# Where's the backup light switch??



## burnt03 (Mar 22, 2005)

Crawled under the truck today to try to test backup light switch, found 2 connectors near the shifter and 3 more that look to be on the transfer case. 

Any ideas which one is it??









Here's the two near the shifter











Two of the rear-most ones that look to be off the transfer case


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## smj999smj (Jan 1, 2006)

Back up light switch would be on the trans. Would help if you have a year/engine of your 4X4 Hbody. Anyway, it's easy enough to figure out. Just unplug the switch and jump the plug on the harness side. Turn on the key. If the reverse lamps light up, you know you have the reverse lamp switch. Looks like the switch on the right in the top pick has a broken wire. The bottom pic shows a pic of your vehicle speed sensor (on the left).


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## burnt03 (Mar 22, 2005)

smj999smj said:


> Back up light switch would be on the trans. Would help if you have a year/engine of your 4X4 Hbody. Anyway, it's easy enough to figure out. Just unplug the switch and jump the plug on the harness side. Turn on the key. If the reverse lamps light up, you know you have the reverse lamp switch. Looks like the switch on the right in the top pick has a broken wire. The bottom pic shows a pic of your vehicle speed sensor (on the left).


Whoops, for some reason I thought I had it in a sig. It's a 95 with the V6. 

And duh, good idea  Was so caught up in testing the switch by measuring resistance that I didn't even think to do that first. Thanks!

If the one is reverse, what would the other one be? Senses that clutch has to be pressed in to start or something?


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## smj999smj (Jan 1, 2006)

The other switch is the "neutral position switch." All you need to test the revese lamp switch is a continuity tester. Switch will be "open" or no continuity normally and be "closed" or have continuity when the gear position is in reverse. For you switch location, refer to part code "32005" in the diagram below:

Part Detail

Coincidentally, it's the switch on the right that looks like it has a broken wire that is your 'reverse lamp switch.' Maybe you just need to fix the wire.


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## burnt03 (Mar 22, 2005)

Alright, worked on it tonight with mixed success. Removed the switch and bench tested it, no good. Put a little heat onto it, must've burned off some old shmeg on the contacts, and it started working! 

Soldered on some new wire, plugged back into the wiring harness to test and boom! Reverse lights for the first time since I've owned the truck! 

Thread it back in, give it one more try and nothing. Unthreaded it to test again in case one of my solders let go but it worked fine.

I guess whatever is inside the tranny that should be pushing against the switch to activate it isn't working.... is there anything I can really do at this point?


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## smj999smj (Jan 1, 2006)

Any chance the plunger on the switch is worn down and not as long as it used to be?


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## burnt03 (Mar 22, 2005)

It looks in pretty good shape:


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## SPEEDO (Jun 9, 2003)

take it to a parts store and check out the plungers...


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## smj999smj (Jan 1, 2006)

Well, either the switch it worn or the part inside the trans is, which I've seen before. Only fix for the later is to remove and teardown the transmission unless you want to find someone who's good at welding to add a little length to the switch's plunger. I would try a new switch and see what happens.


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