850 standard reverse switch

manoverboard · Post by **manoverboard** » 16 Feb 2011, 15:01

First post for me! This is a great site. Just got this neglected car and want to bring it back to some dignity.

My question is that I have no reverse lites. Took the switch off and it works fine out of the housing. But when it is screwed back in it doesn't work. Does the little plunger thing get harder to push in over time? Will a new one take less pressure to push in? And does the little bit of scoring on the shifter rod in the housing matter? Thanks to whomever answers!

Post by **jblackburn** » 16 Feb 2011, 15:20

Welcome to the site.

Fold up a tiny piece of paper and superglue it to the plunger, just enough to activate it when the car is put into reverse.

I fixed my cruise control brake pedal switch in exactly the same way. Redneck engineering for the win!

And if you want more ideas of dumb things people have done:
http://thereifixedit.failblog.org/

manoverboard · Post by **manoverboard** » 16 Feb 2011, 19:39

I hope you're kidding.

jimmyboy · Post by **jimmyboy** » 16 Feb 2011, 19:54

Sounds like a valid solution to me. A switch is a simple mechanism - it probably just needs a little bit of further travel to make contact any more.

It's the same reason the PNP switches stop working sometimes on the automatics. Many people will tell you it needs a new switch when all it needs is some cleaning and re-adjustment.

Post by **Ozark Lee** » 16 Feb 2011, 21:11

Plan B is to replace the switch but with little or nothing to lose shimming the old one might work.

On the manual transmissions the only function of the switch is to turn on the reverse lights. The rest of the car (the ECU) doesn't care.

The auto slush boxes are much pickier and they do care since the transmission is controlled through the PNP switch as an input.

...Lee

manoverboard · Post by **manoverboard** » 17 Feb 2011, 14:13

Sounds so simple, but don't you have to worry about the paper or glue, etc, wearing off and falling into the case??

Post by **jblackburn** » 17 Feb 2011, 19:50

I try to add a bit of humor to things, sorry if I made a bad first impression.

It shouldn't hurt anything if it does, but superglue holds up a really long time. If you could find a small, thin piece of plastic, something like that might work too - it depends how far it needs to be depressed to activate.