86 4+3 trans

[bluequad]

I just got my 86 3 days ago,it has the 4+3 manual.The problem is tranny shifts just fine but I have no overdrive.I can push the button and nothing happens.The light on the dash doesnt even come on.I feel it may be something electrical,but his is my first vette and I dont even now where to start to look for the cause of this,so any ideas or solutions will be much appreciated.Thanks,Danny

 

[Top]

First check to see if the rod attached to the button is centered over the switch at the base of the shifter and is engaging it. Next replace the front relay (there are two) next to the brake master cylinder. Next would be to test the shifter switch to see if it is working. The fact the light doesn't come on makes me think it is one of those two things.

I'm betting relay.

Good Luck

 

[bluequad]

Thanks,I'll look at those relays and the switch.
Danny

 

[larry bud]

Don't forge the switch

I would also check that the wires haven't come undone from the switch itself. You need to remove the cover of the center console off to take a look.

I soldered that sucker on 3 times and it kept coming off. Finally, the lasting fix was to solder it, then put epoxy over the connection as a type of strain relief.

 

[bluequad]

Thanks Larry,I will check every thing that is mentioned.Does anyone know how I can check these relays?I hate to try and buy new ones then find out they were good.If only that little light would come on.........
Danny

 

[Top]

The relay here from the dealer was $18.22. The car is almost seventeen years old. Your gonnna replace it sooner or later, might at well knock it out now. It's part number 14078915.

Good Luck

 

[bluequad]

Thanks for the part # my local dealer is very hard to deal with so this will make it a little easier,your right with the car being this old I will have to replace several parts sooner or later.BTW this is a great site!!!!

 

[trupp]

86 4+3

The biggest problem I've had with my 4+3 is the 1st gear indicator switch on the transmission. Sometimes I have to jiggle the shifter back and forth towards 1st gear to get the switch to work and allow the overdrive to engage. Does reverse work on your car? No reverse is a sign of a major problem with the 4+3's.

 

[bluequad]

My reverse does work,as far as the 4-speed part goes it works great,it shifts smooth and doesnt grind at all.Im going to see if I can get the relay today that Chris suggested and get the car on the stands and see if I can figure this thing out.I feel it is something simple.
Thanks Danny

 

[bluequad]

I finally got my overdrive to work tonight.I replaced the relay that Chris told me to do and I also checked the switch.The switch was bad so I used a toggle switch I had just to check it out and it worked!!!!!!!I a happy camper right now.I asked the dealer while I was there if they carried the switch but he told me it was dicontinued.Does anybody know where I can get one.Thanks for all the help and suggestions
Danny:s

 

[Top]

The switch from the dealer is NOT Cheap. He could find one for you if he did an old stock check with the dealer network. The good news is any 12v momentary on-off switch will work. Take the old switch and hit the electronics store. You should be able something that will fit. The numbering and letters on mine say

MPA
10SF
ALCO

Look at you old switch carefully. You might just have a broken wire at the switch you can't see. Heat them up with a solder gun and pull the wires off, trim back an inch and reconnect. See if that fixes it.

Glad to hear it's working for you now.

Cheers!!