Back up light issues

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blondie

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My back up lights were staying on all the time. I replaced the switch on the steering column. Now only one backup light comes When the vehicle is put in reverse. Any suggestions. I tried adjusting the new switch with no luck.
 

theblindchicken

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I'd throw the truck in reverse and verify you have voltage at the reverse light with a voltmeter.

If you have voltage, then check the ground. If ground is good, then its the bulb.

If you don't have power, then check it coming out of the reverse switch.

If power out of the switch, then you have a break at a connection or wire somewhere between the switch and the reverse light.

If no power out of the switch, then the switch is faulty and may either somehow need adjustment or replacing.
 

1987 GMC Jimmy

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I have a question. Do those switches wear out over time without going out completely? On my Jimmy and Caprice, you have to put the lever in just the right position or the lights won't come on. Or is it adjustable?
 

Cuba

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Yes, on the automatic it's somewhat adjustable...I believe it's part of the neutral safety switch. But it may be just the spring/wire for shift selection slightly off.

Oh, and they could wear out partially & not completely break. To answer the 1st parr. It's the contacts within the switch. .. they tend to corrode or sometimes dust could accumulate. You could pull it off to clean it up... BUT if you've never done one before, it can be a pain to do. It's at the base of the column & needs to be aligned for trans,ECM, & starter reasons. It can throw a code if not aligned right. I believe it's #21
 
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smoothandlow84

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Check for a bad ground. Mine was loose causing almost the same issues as yours
 

HotRodPC

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I have a question. Do those switches wear out over time without going out completely? On my Jimmy and Caprice, you have to put the lever in just the right position or the lights won't come on. Or is it adjustable?

Also if you have any grommets to the shift linkage or the shift linkage itself is wore, then it can put the gear selector in the wrong position to hit the switch even if it is in the correct position.
 

blondie

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Thank you guys for the replies. I will give your suggestions a try and let you know what happens.
 

chengny

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I have a question. Do those switches wear out over time without going out completely? On my Jimmy and Caprice, you have to put the lever in just the right position or the lights won't come on. Or is it adjustable?

At one point a few years ago I was having the same trouble keeping the back-up lights on as you. Most of the time it wasn't really an issue.

But it does become an issue when - in order to keep the back-up lights illuminated - you have to keep upward pressure on the shift lever with your right hand while trying to back down a steep dark driveway in the middle of the woods with just your left hand.

Just so happens that I have a steep dark driveway in the middle of the woods. So one day I decided to at least look at the switch. Often that's as far as I get.


This time however, I fixed it. Took about 2 minutes and zero dollars.

While I was poking at one side of the switch with my finger, the entire assembly made a ratcheting sound and rotated around the steering column. Seems that the plastic housing (which sets the open/close point for the contacts within) is infinitely adjustable.

It might take a few minutes to dial it in, but it is time well spent. Basically, the procedure goes like this: put your gear shift in R and then (with the key on) have someone watch the back-up lights. Push the switch one way or the other - I forget - until the back-ups come on.
 

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