Reverse light not working and is the switch unit serviceable?

[DrJeff]

I've got a collection now of reverse light switches that don't want to switch the reverse lights on when the transmission is in reverse. Yes, I did check the wiring to the lights and it is 100% - lights come on reliably when the two wires to the switch are shorted.

So that really only leaves the switch (unless there is some strange sort of grounding through the transmission, hmmm... naw). Question is, can one of the switches I have be serviced? Looking at the switch itself the bearing and spring must enter from the back - i.e. where the black plastic plug is with the two contacts inside. The switch is ON when the ball bearing runs into a dimple inside the transmission, and thus a depressed bearing is OFF. The black-end does spin, unfortunately does not unscrew. Tried pulling like made, but no joy. Short of drilling out the black plastic end cap, does anyone know how to open the switch.

Jeff
#6313

[DMCMW Dave]

Have you tried connecting the wires to the switch OUT of the car? (with the ball "out" the lights should be on). I've seen one car now where the switch did not work unless it was out of the trans, actually it only needed a washer to work. For some reason the ball did not drop far enough when installed. 12mm copper washer worked fine.

The switch is not grounded to the trans so that is not the issue.

Why would you mess with taking apart a $19 switch? It is crimped together and I'm sure it's not serviceable.


I've got a collection now of reverse light switches that don't want to switch the reverse lights on when the transmission is in reverse. Yes, I did check the wiring to the lights and it is 100% - lights come on reliably when the two wires to the switch are shorted.

So that really only leaves the switch (unless there is some strange sort of grounding through the transmission, hmmm... naw). Question is, can one of the switches I have be serviced? Looking at the switch itself the bearing and spring must enter from the back - i.e. where the black plastic plug is with the two contacts inside. The switch is ON when the ball bearing runs into a dimple inside the transmission, and thus a depressed bearing is OFF. The black-end does spin, unfortunately does not unscrew. Tried pulling like made, but no joy. Short of drilling out the black plastic end cap, does anyone know how to open the switch.

Jeff
#6313

[ccurzio]

I've seen one car now where the switch did not work unless it was out of the trans, actually it only needed a washer to work. For some reason the ball did not drop far enough when installed. 12mm copper washer worked fine.

THANK YOU FOR THIS.

I just replaced my completely dead reverse light switch with a brand new one from DMCH a few weekends ago, and while it kinda-sorta worked it was still pretty flaky at best. After seeing this post of yours, I went out and jacked up my car, pulled the switch, popped on a copper washer, reinstalled the switch and tightened it nice and snug, and now my reverse lights work flawlessly and properly every time!

[dmcerik]

I've seen one car now where the switch did not work unless it was out of the trans, actually it only needed a washer to work. For some reason the ball did not drop far enough when installed. 12mm copper washer worked fine.


Dave, bet you didn't think you'd get to use that bit of knowledge so quickly!

FYI: those reverse lights work great! Thanks for spending the time to diagnose and fix that before we left.

[DMCMW Dave]

Dave, bet you didn't think you'd get to use that bit of knowledge so quickly!

FYI: those reverse lights work great! Thanks for spending the time to diagnose and fix that before we left.

No, I didn't.

Something is weird here, because I had NEVER seen this before last weekend when we ran into it on Eric's car. I wonder if whoever makes that switch just lost a dimension somewhere. I don't really know if that switch is a "new" or NOS part.

[ccurzio]

No, I didn't.

Something is weird here, because I had NEVER seen this before last weekend when we ran into it on Eric's car. I wonder if whoever makes that switch just lost a dimension somewhere. I don't really know if that switch is a "new" or NOS part.

Houston's online store (where I ordered mine) says its NOS, for whatever that's worth.

[DMCMW Dave]

Houston's online store (where I ordered mine) says its NOS, for whatever that's worth.

I now believe that's correct, that they are NOS. So an interesting coincidence so far.

[dmc6960]

I've had two previous reverse switches fail on me. But I honestly dont think I ever checked them OUT of the transmission. Of course I dont have them anymore either. The third one has stayed working for a while now though so in addition to flaky tolerances I think the switches themselves are also hit and miss.

[DrJeff]

Have you tried connecting the wires to the switch OUT of the car? (with the ball "out" the lights should be on). I've seen one car now where the switch did not work unless it was out of the trans, actually it only needed a washer to work. For some reason the ball did not drop far enough when installed. 12mm copper washer worked fine.

The switch is not grounded to the trans so that is not the issue.

Why would you mess with taking apart a $19 switch? It is crimped together and I'm sure it's not serviceable.


Why service a $19 part? You got me... I'm cheap. And, I'm just curious how the thing works, since I have a few no loss in 'servicing' one. I got my last one (currently installed and not working) from DMCH. Could have chased down a replacement, but its a $19 part... so maybe I'm not cheap after all.

When I was last messing with it, I did get the switch working outside the car. Just frustrating as heck why it wouldn't work when installed. So the 12mm copper washer solution might just work for me! THANKS

Jeff
#6313

[Ron]

Why service a $19 part? You got me... I'm cheap.
Na, cheap is when you fix your oil sending unit and have one on a core engine... :headbang:

[DrJeff]

Tonight I tried the the copper washer (5/8 ID) solution to the Reverse Light Switch - no luck. Even with two washers the reverse light won't come on. If I cross the two wires going to the switch I get the reverse lights to come on. So this can only mean that the switch is a dud :t2:

I did get the old A/C drain out - by cutting the hard plastic elbow and then pulling the attached pipe through the existing hole in the frame (WARNING : if you need a image - like pulling out a tapeworm - you were warned!). It turned out that there was dirt or something in the narrow diameter hard plastic elbow. I then super-glued a 1/2in OD, 3/8in ID to the end of a coil boot (straight through). I folded down the edge of the boot over itself, fed the pipe back through the hole (it didn't want to go), and then folded up the coil boot around the drain out of the A/C. I'll get a chance to test tomorrow - every day in Houston is humid so no worries there.

Next up - Both tie-rod end boots

[Marigolo]

Hi, I'm finding myself in the same situation (no reverse light). What is the best way to access the reverse switch to check it? It HAS to be accessed under the car, correct? Any pointers and things to look out for would be greatly appreciated.
Thanks!
Mario.

[David T]

Hi, I'm finding myself in the same situation (no reverse light). What is the best way to access the reverse switch to check it? It HAS to be accessed under the car, correct? Any pointers and things to look out for would be greatly appreciated.
Thanks!
Mario.

Yes, you can only reach it from underneath. Before removing it try jumping the 2 wires together. With the ignition switch on the reverse lights should light (not uncommon for the bulbs to be burnt out and/or the taillight boards to have bad connections). Very common for one or both wires to not be connected to the switch so all you have to do is tighten the terminal and slip it back on and try to get the rubber boot over the switch. It seems no one cares about working reverse lights so no one spends the money to get them fixed. The only people who are interested in fixing them are the anal owners who want everything on the car to work and try to fix it themselves (I count myself in this category). If you have an automatic it is a little more complicated.
David Teitelbaum

[Marigolo]

Yes, you can only reach it from underneath. Before removing it try jumping the 2 wires together. With the ignition switch on the reverse lights should light (not uncommon for the bulbs to be burnt out and/or the taillight boards to have bad connections). Very common for one or both wires to not be connected to the switch so all you have to do is tighten the terminal and slip it back on and try to get the rubber boot over the switch. It seems no one cares about working reverse lights so no one spends the money to get them fixed. The only people who are interested in fixing them are the anal owners who want everything on the car to work and try to fix it themselves (I count myself in this category). If you have an automatic it is a little more complicated.
David Teitelbaum

Thanks David, I'm one of those anal owners also :-) I also want my backup camera to work again, and it's powered by the reverse lights.
I will have access to a small lift on friday to make things easier and I will follow your advice. Are there any lower panels or plates to remove in order to gain access to the switch or is it pretty easy to get to? Just by lying on the floor I can't seem to locate it.
Thanks!
Mario.

[NightFlyer]

Yes, you can only reach it from underneath. Before removing it try jumping the 2 wires together. With the ignition switch on the reverse lights should light (not uncommon for the bulbs to be burnt out and/or the taillight boards to have bad connections). Very common for one or both wires to not be connected to the switch so all you have to do is tighten the terminal and slip it back on and try to get the rubber boot over the switch. It seems no one cares about working reverse lights so no one spends the money to get them fixed. The only people who are interested in fixing them are the anal owners who want everything on the car to work and try to fix it themselves (I count myself in this category). If you have an automatic it is a little more complicated.
David Teitelbaum

What's this 'rubber boot' that goes over the switch? Can you reference it in the parts manual? Or provide a picture of it?

I'm curious, as the wires going to my reverse switch are just plastic encapsulated spade connectors, just like on the door lights/buzzer switches and engine compartment light switch.

Thanks!

[NightFlyer]

Thanks David, I'm one of those anal owners also :-) I also want my backup camera to work again, and it's powered by the reverse lights.
I will have access to a small lift on friday to make things easier and I will follow your advice. Are there any lower panels or plates to remove in order to gain access to the switch or is it pretty easy to get to? Just by lying on the floor I can't seem to locate it.
Thanks!
Mario.

No - nothing to remove to access it. You should be able to see it by lying on the floor on the driver's side and looking up - it's the round thing in the gear box housing that's about the circumference of a half dollar with two spade connectors coming out of it and two wires connected to it (assuming it's hooked-up).

I'll take a pic of mine and post in few.

217572175821756

[Marigolo]

No - nothing to remove to access it. You should be able to see it by lying on the floor on the driver's side and looking up - it's the round thing in the gear box housing that's about the circumference of a half dollar with two spade connectors coming out of it and two wires connected to it (assuming it's hooked-up).

I'll take a pic of mine and post in few.

217572175821756

THANK YOU!! Sometimes it's just a matter of knowing what you're looking for! :thumbup: