4+3 button fix
Thread Starter
Cruising
Joined: Mar 2005
Posts: 14
Likes: 1
From: Lincoln Nebraska
4+3 button fix
I tried a search and found nothing. I know there has to be something on this board about fixing this in a 87. How much does this generally cost. I am looking to buy one and the button does not work and I want to use this in negotiations. What is the most common source of the problem? Is it the button itself or the overdrive unit? Thanks for your help.
Race Director
Joined: Oct 2004
Posts: 10,719
Likes: 18
4+3 overdrive
Below the gearshift lever, under the boot, the is a rod that goes down from the switch button to actuate a micro-switch that engages and disengages the O/D operating through the computer. This switch appears to have come from Radio Shack, but such is not the case. It cost me (hold on to your hat) $120.00 from the dealer. That was the only place I could find one. Perhaps a wrecking yard or salvage yard may have one. They are very fragile,so use care. A simple continuity check can tell you if it is working or not.
Team Owner
Joined: Mar 2000
Posts: 83,381
Likes: 87
From: Boston, MA
If you buy it from Ecklers it is $125. If you buy it online at another vendor it is $11, but without the wire harness (easy solder job to transfer it). 
Oh yeah.... common source is just the button going bad. This is assuming that the overdrive works perfectly except for manual override with the button.
Oh yeah.... common source is just the button going bad. This is assuming that the overdrive works perfectly except for manual override with the button.
Team Owner
Joined: Mar 2000
Posts: 83,381
Likes: 87
From: Boston, MA
Originally Posted by ballox
contact 88BlackZ-51 he fixed his for a few dollars on his own
http://www.newark.com/
For 1986-1988 use P/N: 61F753
Ooops sorry, it is $12.30 now.
http://www.newark.com/NewarkWebComme...SKU=61F753&N=4
Advanced
Joined: Dec 2004
Posts: 50
Likes: 0
I have the same problem with my switch, I just went down to radio shack and bought a switch, but I think I got the wrong kind. Anyone know how the factory switch function. When I wire it, the over drive is alway off. Then when I press the button , over drive comes on. When I release the button, overdrive goes off. If I switch the wiring, it does the same, but opposite. Is the push button switch supposed to work like a toggle. ie. press it for 12 volts, then press it again to toggle it off?
Advanced
Joined: Dec 2004
Posts: 50
Likes: 0
Nevermind, I bought a momentary switch, when I needed an on/off switch. Only cost $3.50 or so a Radio Shack.switch The second one on the right is the size you want, but make sure it when you go get it isn't a momentary switch, they have both. The one you want has a red top. Not bad for a $140 factory part!
Last edited by ddorlando; May 7, 2005 at 05:11 PM. Reason: edit
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Heel & Toe
Joined: Feb 2005
Posts: 24
Likes: 0
From: SE MA
It may be just a frayed wire at the switch like it was on both my and my father's 4+3 equipped cars, it's a common problem. The wire fatigues and frays to the point at which it breaks off the switch's solder tab. I soldered the harness to the ground and normally open (N O) leads on the switch and it worked perfectly. After determining the switch was good, the overdrive still did not work. I believe the bad connection in the switch caused the relay to fail, $17 for a new relay and I was back in business.
Good luck.
Good luck.