O/D relay wiring question

[Uwe Blab]

I posted this in the '47-'59 forum, but haven't gotten any responses, so I thought I'd try it here...

I am, what is hopefully, in the final stages of installing a 3-speed transmission with electronic overdrive. The transmission is out of a '55 truck, but I'm putting it in a 1970 C/10. The question I have is regarding the relay. I've acquired a 3-post version out of a F**d, but I'm not sure if it may be what's keeping the transmission from kicking into o/d. It has a connection for the transmission solenoid, kickdown switch, and the battery, but only when the ignition is turned on. I had a 4-post relay, which had an additional connection to the battery permanently, but it was a faulty relay.

Bottom line, should the 3-post relay be sufficient to run the transmission?

Thanks in advance for your help.

Adam

[dwcsr]

It all depends on how its wired and Is this the type with a lever on the side ort just a solenoid or solenoid and lever?

[Uwe Blab]

Originally Posted by dwcsr

It all depends on how its wired and Is this the type with a lever on the side ort just a solenoid or solenoid and lever?

Not sure if I understand what you mean by lever? I'm relying on the solenoid (and governor) to engage and disengage the overdrive, and not override it with a lever in the cab. The only thing I'll have in the cab is the pull cable to lockout the overdrive.

[raycow]

Originally Posted by Uwe Blab

Bottom line, should the 3-post relay be sufficient to run the transmission?

3 terminals on the relay are enough. The connections should be ignition(switched power), solenoid, and throttle switch. If you don't have a throttle (kickdown) switch, connect the throttle switch terminal to the governor and put a toggle switch in that lead so you can downshift the O/D when you are above the cut-in speed.

If I remember correctly, the 4 terminal relays had a fuse clip on them.

To test, first make sure you have power at the relay and then ground the throttle switch terminal. Both the relay and the solenoid should click.

If the relay turns out to be bad (and they almost never die) you can use an ordinary "cube" relay that you can get at any parts store for cheap.

Ray

[Uwe Blab]

Thanks for the info raycow. As a follow up, is there a way to test the governor to see if it's okay? And if the governor isn't working, is it possible to take it apart to fix...oh, AND put back together to reinstall?

[raycow]

Originally Posted by Uwe Blab

is there a way to test the governor to see if it's okay? And if the governor isn't working, is it possible to take it apart to fix...oh, AND put back together to reinstall?

Yes, you can test the governor, but you will need to get the truck up to at least 30 mph, either on the road or on a lift. Use a test lamp or multimeter to make sure the governor contacts close (to ground). The governor can be opened and repaired if necessary. It has a relatively simple centrifugal mechanism that closes the points at about 1500 rpm (driveshaft speed), but if you need parts for it they won't be easy to find.

Ray

[Uwe Blab]

Thanks again Ray.

Adam