Overdrive relay

[capyjack]

I recently bought one of the aftermarket six volt OD relays.
None of the terminals are marked and I have yet to find the right combination to make it work.
I did find a site that identifies the identical looking 12 volt relays terminals but that doesn't seem to work for my six volts.
The 12 volt info suggests that the battery is connected to the post with the fuse. This makes sense but as soon as I hook up the battery the relay clicks, thus would be activated whenever the battery is hooked up.
The seller here hasn't a clue and I am lost as well.
This is a 48 Jeepster that runs and drives well but non op OD.

[gmwillys]

Here is a diagram from Willys America, for Jeepsters. I do not know much about the Jeepster set up, but I would think it would have to go through a kick down/or dash switch.

https://shop.willysamerica.com/Overdrive-Relay-p/916721.htm

[capyjack]

Thanks GM,
Yes, this is the 12 volt diagram, there is no diagram on the 6 volt offering.
I wired it up as per the 12 volt picture and it does not work, it clicks as soon as I hook up the battery, I suspect that the battery would be dead in a short while.
I was in hopes that someone here would have the info that I need.

[LarrBeard]

I was in hopes that someone here would have the info that I need.

I'll bet that the Jeepster and Kaiser-Frazier had a lot in common.

From a description:

The overdrive was of the automatic type; all one had to do to engage it once the control knob was set was lift off the gas pedal slightly. Pushing down hard on the gas pedal would disengage overdrive for quick passing maneuvers or climbing hills. Four-wheel drive was never offered; apparently it wasn't even considered by Willys.

Here is a link to a great description of the Borg-Warner overdrive and all the stuff that goes around it. There is a diagram of the relay, the solenoid, the kick down switch and even the rail lockout.


http://www.kaiserbill.com/Web-PDF/KF-Overdrive.pdf

[gmwillys]

I'll bet that the Jeepster and Kaiser-Frazier had a lot in common.

From a description:

The overdrive was of the automatic type; all one had to do to engage it once the control knob was set was lift off the gas pedal slightly. Pushing down hard on the gas pedal would disengage overdrive for quick passing maneuvers or climbing hills. Four-wheel drive was never offered; apparently it wasn't even considered by Willys.

Here is a link to a great description of the Borg-Warner overdrive and all the stuff that goes around it. There is a diagram of the relay, the solenoid, the kick down switch and even the rail lockout.


http://www.kaiserbill.com/Web-PDF/KF-Overdrive.pdf

Great! That is a good find LarrBeard.

[capyjack]

This relay that I have is not marked as to which terminal is which.
It is also common to Studebakers and Fords and other six volt negative ground cars as many suppliers sell this relay.
BUT NO ONE KNOWS WHICH TERMINAL IS WHICH. And when I do wire it up according to the info supplied with its 12 volt counter part it not correct.
I know how it works and how to drive it and I have seen probably hundreds of diagrams but NO ONE can identify which terminal is which on this 6 volt relay.
Its the exact one that GM shows above but is six volt.

[gmwillys]

With the schematic that LarrBeard provided, the battery (6 volt) voltage is applied from the starter solenoid/ (starter positive post if a starter pedal is used)to the fused link (1), as you figured to be correct. The Ignition terminal (2) goes to the negative side of the coil, in which it goes through the ignition switch. This is where the relay is turned off and on through the ignition switch. The 3rd terminal goes to the kick down switch terminal A. Then the remaining terminal (4) goes to the Solenoid terminal 4. With all this being said, the make up of the relay is very similar whether it be 6 or 12 volts. The relay that is pictured bellow from Kaiser Willys, and it is 6 volt.

https://www.kaiserwillys.com/category/overdrive/factory-rebuilt-overdrive-relay-6-volt-fits-46-55-station-wagon-jeepster-with-planar-suspension

If your relay does not match with what we are talking about, please include pictures of what you do have. It tends to help us realize exactly what we are talking about.

[LarrBeard]

BUT NO ONE KNOWS WHICH TERMINAL IS WHICH. .

Here is how to figure out just which ternimal is which:

The solenoid relay is a four terminal device. The relay coil is connected between the throttle (TH) and ignition (IGN) terminals, which are interchangeable.

The other two terminals are the solenoid (SOL) and battery (BAT) which are also interchangeable.

Take your meter set up to measure continuity and find the two terminals that are connected together through some relatively low resistance. These are the TH and IGN terminals – they are interchangeable, just two ends of a coil of wire in the relay.

Once you find these two terminals, the other two are the SOL and BAT terminals. With your meter, verify that there is no continuity between those two terminals.

Connecting the BAT terminal should not do anything to energize the relay. It should only energize with the IGN and TH terminals connected. There may be a wiring harness issue somewhere.

[capyjack]

Thank you LarrBeard, I think this is what I am looking for.
You make it sound pretty simple and being rather simple myself.....LOL
A couple of questions.
Would the (TH) and the (IGN) as well as the (SOL) and (BATT) typically be on opposite ends of the relay as you illustrate?
Also, does the relay need to be grounded to function properly?

The relay looks exactly like the one in the link that gmwillys provided above, however mine is marked as a six volt unit.

I will reply soon when I get back to this.

[capyjack]

With the schematic that LarrBeard provided, the battery (6 volt) voltage is applied from the starter solenoid/ (starter positive post if a starter pedal is used)to the fused link (1), as you figured to be correct. The Ignition terminal (2) goes to the negative side of the coil, in which it goes through the ignition switch. This is where the relay is turned off and on through the ignition switch. The 3rd terminal goes to the kick down switch terminal A. Then the remaining terminal (4) goes to the Solenoid terminal 4. With all this being said, the make up of the relay is very similar whether it be 6 or 12 volts. The relay that is pictured bellow from Kaiser Willys, and it is 6 volt.

https://www.kaiserwillys.com/category/overdrive/factory-rebuilt-overdrive-relay-6-volt-fits-46-55-station-wagon-jeepster-with-planar-suspension

If your relay does not match with what we are talking about, please include pictures of what you do have. It tends to help us realize exactly what we are talking about.


Wait, you said negative side of coil? Would that not be the distributor side?
The Jeepster is negative ground.
The lead to the pedal switch is on the negative side I think.

[capyjack]

Well, I couldn't stand it and had a few minutes.
The only terminals that have continuity on this relay are on the same end of the thing and one of them has the fuse.
So, I am thinking that maybe the fuse is on the (IGN) post of the relay.
So I hooked those two up (TH and IGN (to the fused terminal))as suggested and the remaining two on the other end of the box also.
At least now I don't get a click when I hook the battery up.
I also don't get any reaction when I turn the key on. The rail switch is closed, all I did was put the ohm meter on it so don't know if there is any voltage there.
Is this a good thing?
Does the governor have to be spooled up to provide a ground to the solenoid to trigger the relay?
So maybe I wont know if its working until I drive it again?
Would a good test be to hook a ground to the governor lead to see if the relay activates?
Sorry if I am asking stupid questions but having the thing wired up and being able to hook up the battery is kind of a big change here.

I should also add that I picked up this car as an unfinished project, it had been rewired, the OD harness was not dealt with however, but was included, the relay was missing.
I am pretty sure that I have the OD harness installed correctly now as there were pretty good instructions for that included in the boxes of parts. Also a new kick down switch which works as it kills the engine if I floor it.
If I could get comfortable with the wiring installation I would hope that the OD would activate.
If it doesn't then I will be doing more trouble shooting, I see this as fairly simple puzzle but this unmarked relay has been throwing me.

Thanks again, Jack

[LarrBeard]

You asked:

A.Would the (TH) and the (IGN) as well as the (SOL) and (BATT) typically be on opposite ends of the relay as you illustrate?

Close, but not really. Here are two configurations of relays from Willys America.

https://shop.willysamerica.com/Overd...y-p/916721.htm

BAT is the terminal with the fuse. TH and IGN seem to be opposite each other at opposing ends.

B. Also, does the relay need to be grounded to function properly?

No, none of the terminals is a ground and the metal case is only a mechanical mounting bracket.

[LarrBeard]

We are crossing emails and asking a lot of questions too fast for my old brain to handle. Before this morning I had no idea how an overdrive worked so I can’t claim to be any kind of authority after just a day of looking. I have looked at Studebaker and Kaiser-Frazier/ overdrives and they look a lot alike. Here are the things I can say with some degree of certainty.

A. The terminal with the fuse is the BAT terminal. That ties directly back to the battery and has no other overload protection so the fuse is in the high current path from the battery to the solenoid. The fuse is a 20-amp fuse; it is in the solenoid-battery circuit. The terminal with the fuse is neither TH nor IGN.

B. The vehicle has to be moving for the switch contacts in the governor to close.

I am enclosing scans of the three pages from the Willys-Overland Shop manual that speak to truck overdrive operation.

Examine the wiring diagram on page 149 to see the three circuits that control overdrive operation.

We really need to see a photo of your relay if we are going to get much further.

[gmwillys]

I agree with LarrBeard. Four wheel drives do not use the automated overdrive units, so this is a new subject for most of us. I know I as well have never looked into how and why the system worked, although it seems fairly straight forward. Testing will require driving, because the overdrive will not kick in until 30 MPH is attained. There are several things that have to coordinate with each other before the overdrive will engage. Once you have everything dialed in, it should work fine. Education by trial and error tends to be the best way to learn.

[LarrBeard]

Well, a new day and we still don’t all know for sure just what the relay terminals are and what they do. It is time to do some creative poking around and figure this out once and for all – then we will be “authorities” on the subject. We can awe folks with what we know about an ancient and elusive secret. Our wives will think we are geniuses. Yeah, sure …. .

I suggest that we do some off the vehicle testing. Bring the relay to the bench or kitchen counter and gather up a meter, a couple of clip leads and one of those big square 6-volt lantern batteries. If you have a 6-volt vehicle, one of those batteries comes in as handy as a half-inch box end wrench many times. You can test this or that without trying to connect up to the vehicle battery.

IF, and notice that I highlighted IF, we have the relay we think we do - it is a simple single pole, single throw relay with a 6-volt coil and normally open contacts rated at about 15-amps or so. It’s a big relay, but in no way is it exotic.

Use your meter to find the two contacts that have continuity between them. I would guess that the resistance of the relay coil would be about 10-12 ohms, but that is just a guess. It won’t be zero and it won’t be several thousand.

Using the clip leads, connect the battery to those two terminals. You should hear the relay armature clunking on and off. Once you get the “clunk”, we’ve found the coil of the relay. Those are the TH and IGN terminals of the relay.

The other two terminals will be the BAT and SOL terminals. Everything I see anywhere says the BAT terminal has the fuse tied to it. Use the meter set up to measure continuity or low ohms and verify that when the relay armature goes “clunk”, the fused terminal connects to the remaining terminal.

Now, if this doesn’t happen, we have a different relay than anything I’ve seen described in the literature or something is bad. Once we figure out just what is where on the relay, we can move on to looking at something else if needed.

A picture of the relay would be a help, and of course a picture of the Jeepster!

Hang in there, we’ll figure this out too.

[capyjack]

OK, I have been spending some time here and I am finding that the only two terminals on the relay that have continuity are the one that has the fuse (batt) and the (TH) terminal.
Earlier suggestion was that the continuity should be the IGN and TH.
If I hook the hot wire from the battery to the fused terminal (and other wires accordingly) the relay activates as soon as I hook up the battery.
Therefore I switched the wires from the battery and the ignition on the relay.
I drove the car and still have no OD.
However I am getting some clicking at the relay once in awhile by turning on the ignition.
So lets assume that the main feed to this relay wants to go to the IGN post suggested in the image and the switched feed goes to the fused post on the relay.

The trouble shooting page in Jeepster Mechanics manual says to check that the governor wire be "hot" with the ignition on and the OD lever pushed in. The governor lead is not "hot" when I do that.
I was under the impression that the governor supplied a ground when it is spooled up so I may not be understanding this. It also could be that it does indeed supply a ground to the solenoid which in turn sends power to the relay to activate it.
This is where I am confused.
I am hoping that I can attach the info that the vender supplied as well as the pics you guys have been asking for.
The "6V" was written on the relay when I got it.
Where you see the "sol" and "ign" I wrote on there from the info in the first image, which is supplied by the vender for the 12 volt unit.

I very much appreciate the help here and I am in hopes that your wives will consider you to be geniuses. I don't have one so I just want to impress myself.
Thanks, Jack

[LarrBeard]

The pictures show a lot of info I was wondering about. It helps that you have a replica original wire harness. Hopefully whoever did the harness made a faithful copy, including wire colors.

In the picture of the relay on the fire wall, there is a red wire with three white tracer strands. That is a fairly heavy wire. In the wiring diagram I scanned and sent you, on p. 149, the wire identified as “Red-3 White trs” goes from the battery terminal to the upper left corner of the relay in the illustration. That is the terminal with the fuse on it. Incidentally a “Red – 3 White trs” goes to the upper terminal of the voltage regulator as well. “Red 3-White trs” is the color code for a primary battery lead. Red- 3 White Tracers is the BAT lead.

There is another wire, Blue with 2-white tracers. That is the wire corresponding to the SOL wire in the wiring diagram.

I see a green wire, I cannot see what the tracers are, connected to the relay. In the diagram the green wire with 2 blue tracers should go from the (–) side of the ignition coil to the bottom terminal of the kickdown switch. It should not be connected to the relay.

On the left lower corner of the relay is a wire that looks yellow(?) with multi-colored(?) tracers. I can’t find anything like that in the wiring diagram. Did a wire list come with the job? See if you can find a Yellow – whatever wire in the list and see where it might go. The guy who put the harness in my ’48 wired some things together that got wires really hot – fortunately nothing damaged.

One of the Jeep rules – trust no work that someone else did before you got the vehicle.

What I don’t see are a couple of black wires with 2-white tracers. One would go from the (+) side of the coil to the IGN terminal of the relay, the other would go from the relay (TH) to the kickdown switch. Is there an extra wire on the + terminal of the coil?

Just looking at pictures, I would guess that you have the relay shown on the right, the one called “Overdrive Relay 1948 to 1955”


Here would be my guess at terminal layout and wire colors:

TH IGN
(Black, 2 wht tracers) (Black, 2 wht tracers)


BAT SOL
(Red, 3 wht tracers) (Blue, 2 white tracers)

That attempt at a diagram didn't turn out well ... stinkin' editor tool ...

I can’t explain the odd continuity from BAT to TH. Internal failure or damage? I'd be about ready to carefully pry the case off and take a look inside to see just what is going on in there.

I would suspect that the 6V on the case was just someone’s way to identify that as a 6-volt relay. And, oh by the way, I really like the color! It looks familiar...

[capyjack]

Thanks for this Larr.
It will be a week or so before I can get back to this.
I kind of thought that I may have a bad relay. I bought it from this site KW even though it cost a hundred more than the competition.
I doubt that it has any kind of warrantee as its electrical and I have tried several installs.
Taking at apart will certainly cost me $250. However that would be worth it if I could get the stupid thing to function.

[LarrBeard]

Wow! I really like the two tone red. Nice Jeepster.

If you look at the case for a while, I'll bet you can figure out how to get the can off without hurting the innards. It may take a couple of slits around the edge of a crimp to get some pry room. I'll bet it's built on a insulation base with the lid just as a cover.

I've done that with the original bimetal oil pressure sensor on the '48. I used RTV sealer to close it back up.

Oh, by the way, on the truck the primary battery leads are red with 3 white tracers too.

[capyjack]

LARR said - Use your meter to find the two contacts that have continuity between them.
OK, I have continuity between the SOL and IGN terminals as well as continuity between the TH and BAT terminals.
Applied voltage to the TH and BATT makes the click. The SOL and IGN is more like a short.

LARR said - Those are the TH and IGN terminals of the relay.
But one is clearly the fused terminal.

My Jeepster manual suggests that there be voltage at the governor lead when the OD is turned on. I don't have any voltage there so I cheated some voltage to it and the car drives locked into overdrive. (side note: the car wont go into reverse this way)
Back to the trouble shooting section. symptoms', "Relay clicks at idle or as soon as ign. is turned on. Vehicle is in overdrive from a standing start. Impossible to shift into reverse. Impossible to pull out of overdrive plunger. Impossible to tow or push"
My relay clicks when I hook up the battery, also sometimes clicks when I turn the ignition on.
Manual "probable remedy" "Short or ground in relay control circuit. Check wiring, relay, kickdown switch, rail switch and governor for short or ground. Faulty governor. Replace. Faulty relay or solenoid. Replace.

Needless to say I am very suspect of this relay that I paid KW $250 for.
So I took it apart as suggested. Knowing nothing about these it all looks good, No smoked wires, no bad smell, all looks new,

[capyjack]

LARR said - Use your meter to find the two contacts that have continuity between them.
OK, I have continuity between the SOL and IGN terminals as well as continuity between the TH and BAT terminals.
Applied voltage to the TH and BATT makes the click. The SOL and IGN is more like a short.

LARR said - Those are the TH and IGN terminals of the relay.
But one is clearly the fused terminal.,

I should add that when the relay is tripped by applying voltage to the BATT terminal and a ground to the TH terminal I get voltage at both the IGN and the SOL terminals.
Still stumped.

[LarrBeard]

I should add that when the relay is tripped by applying voltage to the BATT terminal and a ground to the TH terminal I get voltage at both the IGN and the SOL terminals.
Still stumped.

Is this with the relay out on the bench or in the vehicle wiring harness?

If you get a voltage on the IGN and SOL with the relay on the bench with nothing connected to those terminals, I think it is time to open up than can o'worms and see just what is in there.

You've lost the "warranty" by hooking it up. SOmething is going on in there that just doesn't make sense.

Anyone else got an idea??????

[capyjack]

Yes, out on the bench.
Positive voltage to the terminal with the fuse and a ground to the TH terminal. This activates the relay and puts voltage to the IGN and SOL terminals.
I opened it up but don't have any idea what to look for.
Its clean and new and doesn't show any signs of being hot.

[gmwillys]

I don't have the diagram right in front of me, and these derned tablets don't multitask well at all. The relay must still be hooked up from what I gather.

Having power at batt terminal and ground at the throttle terminal is correct when the throttle is not fully depressed. The ignition having power is correct when the ignition is in the run position. The solenoid having power also sounds right, if then the solenoid is controlled by the governor. That is my fuzzy part. The document from Frazier had a governor, but I don't know 100% that Willy's used one or not. The governor would engage the solenoid above 30 mph, then kick out at full throttle via the throttle switch ground being interupted. Check over my recollection to see if that makes sense.

[LarrBeard]

We're guessing as to how this thing is wired. We "think" it is wired like a truck or wagon, but we don't have the early service manual to look at.

https://www.kaiserwillys.com/category/literature/mechanics-manuals/mechanics-service-manual-fits-46-50-truck-station-wagon-jeepster

Since I have a '48 truck, I'm going to take my own advice and break down and buy one of these.

[capyjack]

GM and Larr,
First let me thank you guys for your info and for your patience with me.
It was a tough decision to have to step up and re-buy a fairly expensive relay.
However with that said.
THE NEW RELAY FIXED IT !!!! YEAAA !!!!
Yesterday was a good day in Oregon with a blue sky and 45 degree temps I took the Jeepster for a fridged drive for an hour or so. (the top will be the finishing touch)
I love these forums and the information they provide. The world has become much smaller with the internet.
Cheers, Jack

[capyjack]

Larr,
Dang, since this is not one of my regular stops I did not realize that I had private messages here.
Sorry about that I didn't mean to ignore.

[gmwillys]

I'm glad that LarrBeard's leg work came through yet again. Enjoy the remaining nice days, keep us in mind while you are out and about. Take some photos of your travels!

Enjoy!

[LarrBeard]

How about that!

I suspect that when someone fabricated the original relay, they crimped an insulator somewhere or pinched a wire. There is just no way that the coil voltage should have shown up on the contacts - they are physically two separate entities.

Some day when you get a chance, give us a good photo spread of the Jeepster. There are just not that many of them in original condition.