Thanks for going for that drive and confirming it's all good! 
4+3 relay question
Thread Starter
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
4+3 relay question
I just replaced my overdrive relay with a new one. The old one worked fine, but it's the original and I just wanted to do a little winter preventative maint. I warmed the engine to 190 degrees idling in my garage. I put it in second gear while keeping the clutch engaged, and flipped the console mounted overdrive switch to "on". position. The dash o/d light did not come on. Does the car actually have to be moving for even the overdrive light to come on. I know it has to be in second gear to engage but I was just sitting still with the shifter in 2nd gear position and the clutch depressed. Any thoughts?
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Try jacking up the rear end so the drive wheels are off the ground. Then with the engine running and trans in 1st, apply light throttle to get the speedo to read about 15-20MPH, then shift to 2nd and then hit the switch.
I don't think the OD indicator should be on if the car is stopped regardless of the shifter position.
I don't think the OD indicator should be on if the car is stopped regardless of the shifter position.
Thread Starter
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
No road speed , VSS =0 ; nothing is going to happen
O/d light indicates the O/d relay has been operated ; nothing else.
Does not indicate " time to shift" into O/d or that the O/d has actually engaged ; only that power is coming out of the relay .
There is no feedback from the unit to indicate that it is engaged or not
Last edited by vetteoz; Jan 5, 2013 at 07:03 PM.
Thread Starter
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
All is well
I didn't want to, but I couldn't resist taking her out of winter hibernation today just for a test drive. I replaced the overdrive relay as well as the fuel pump relay just because the originals were 28 years old. They still functioned perfectly but a little preventative maintainance goes a long way. The overdrive indicator light does work correctly and the overdrive operates as it should. The fuel pressure relay did it's job too. Thanks guys for your helpful replies. 
And yes. I did wash it as soon as I put it back in the garage!
And yes. I did wash it as soon as I put it back in the garage!
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