Hi, I have a 1990 Chevy Corsica 3.1 V6 auto...the lockup for overdive does not disengage...thus I have removed the wire plug to the tranny. The plug has 4 wires, purple, beige, black and green. Does anybody know which wire I can put a switch in so I could
reconnect the plug and obtain overdrive on the highway by the switch. Thanks for your imput.

Ok.......I'm confused, are you talking about the torque convertor lockup or are you talking about overdrive. OD isn't electrical on these units so I'm assuming you're talking about lockup.
Don't hack the wiring, go get a lockup solenoid from GM and replace it.

Hi afRaceR, sorry about the confusion...it is the torque converter lockup. How hard is it to replace the solenoid ? Is it easily accessable once the tranny pan is removed?
Thanks.

There are lots of things that can cause the TCC to stay engaged. Personally considering the cost and aggravation factor.....I'd just leave it unplugged. Done hundreds if not thousands this way with no ill effect.

Phil

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GTDude
OVER 25 years GM experience

Thanks Phil for your input. I've been driving it around unpugged for about 5K miles. Just thought I could get a "quick fix" with a spiced in switch. My wife uses the car mostly around town, so it really doesn't get on the highway that much except once a month when I take it to clean it out.
Peter

Try this: http://www.kichline.com/chuck/fiero/TCC.htm

You can wire in a switch but I think it would be more of a hassle then to actually replace the solenoid. Like Phil said there are a couple of other things that could cause this, 9 times out of 10 the solenoid is what keeps lockup engaged though.

There's really no problems leaving it unplugged for running around town except for slightly less gas mileage. But if you do highway driving - even a couple hundred miles - can burn your transmission up. The lockup function actually helps to cool the transmission fluid.

I would eventually get around to fixing it though.

quote Originally posted by afRaceR: can burn your transmission up.

I agree with everything you said until you came to that burn up part. Temp of the tranny is controlled by the transmission cooler in the radiator which both heats and cools the tranny depending on conditions. Lots of us have had the TCC unplugged for years and I do a 600 mile trip which is 10 hours straight a couple times a year. I might get around to replacing the soleniod toward the end of the summer.

Hey Guys, thanks for more imput..especially the write-up from Purr-fections. I guess I'll replace it when I don't have anything to do .ha.ha.ha in the meantime I can return to work my 86 SE.

quote Originally posted by pja: ...in the meantime I can return to work my 86 SE.

Aha! I knew this had to be a Fiero-related tech question somehow!