reverse light issue

[214martin]

Whats up guys so my truck has had this issue for ever (literally) and its about time i fix it. its a 90 gmc c1500 RCSB 4.3L. when i put it in reverse the lights DO NOT turn on. If i want them to come on i have to hold the lever up like putting it back into park and something it sounds like the gears are grinding so i don't do this. but sometimes i have to if its REALLY dark. i just replaced my tranny so i don't want to do that anymore and possibly damage it. anyone know a fix to this? thanks guys!

 

[90W7]

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#3 should be the source of your problems. I forget if its adjustable or if you should just swap it out with a new one. Haven't had a problem with mine. Hope this helps.

 

[someotherguy]

It has teeth that allow you to ratchet it side to side for adjustment. First try pulling the gearshift all the way down to manual low 1 (far end of travel) then bring it all the way back to park. If that doesn't get it into place, then gently give it a little nudge either way until it works right. If you get it too far out of whack you'll have trouble starting the truck, because it's also your park/neutral safety switch, as well as the reverse light switch.

Richard

 

[214martin]

Sweet thanks guys!!!

 

[214martin]

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#3 should be the source of your problems. I forget if its adjustable or if you should just swap it out with a new one. Haven't had a problem with mine. Hope this helps.

Pictures always help! Lol thanks man!

 

[214martin]

It has teeth that allow you to ratchet it side to side for adjustment. First try pulling the gearshift all the way down to manual low 1 (far end of travel) then bring it all the way back to park. If that doesn't get it into place, then gently give it a little nudge either way until it works right. If you get it too far out of whack you'll have trouble starting the truck, because it's also your park/neutral safety switch, as well as the reverse light switch.

Richard

What if it cant go all the way down?? I only ever put it into The drive with the O around it. But i did try pulling the lever all the way and its weird it start pulling the letters on the cluster down with it and cant go into 1, the farthest is 2. Im scared itll break if i go into 1.

 

[Schurkey]

Searched the forum, and this thread was as close as I got to my issue.

1988 K1500, automatic trans. Backup / Reverse lights don't work.

I need to replace the "Trans Position Switch" which includes the backup light switch, item 3 in the illustration in the #2 post above.

My switch doesn't turn on the backup lights, and it fell apart when I removed the connector for the backup light wiring. The backup lights both work when I jumper the connection, so the power, ground, bulbs, and wiring from cab to taillights is OK, but the backup lights won't work when connected to the switch. There's no switch available locally, I have one on order but it won't be here for a couple of days. Therefore, I can't tell from the new switch how it would be held in place.

I don't see--or feel--any screws, bolts, or other hardware that holds the existing switch in position. I have the "official GM" service manual for my '88. The "electrical" section tells me that the switch installation is covered in the "steering column" section, but apparently they forgot it, 'cause it's NOT listed in the steering column section.

It's also not listed in the Service Manual Supplement, which corrected a heaping pile of other mistakes and omissions in the primary Service Manual. Gotta love "first model year" vehicles, and the documentation that goes with them.

HOW DOES THE TRANS POSITION / BACKUP LIGHT SWITCH COME OFF THE STEERING COLUMN? HOW IS IT ADJUSTED?

Thanks, folks.

 

[someotherguy]

It snaps into the column and ratchets side to side on teeth for you to adjust it.

Or, it's been a whole lot of years, it may slide in, instead of snap - you'll be able to tell by looking at it, for sure.

Richard

 

[Schurkey]

Success! Thanks, in part, to 777stickman sending me a scan of the service manual pages I needed. MUCH APPRECIATED! My service manual--for an '88 model year--was copyright dated in '86. There's a heap of pages my manual doesn't have, that later editions do. Very frustrating. I have a "Service Manual Supplement" that adds some pages, but still not all of them.

As someotherguy said, the switch snaps into position on the steering column of automatic-transmission cars. (Reverse switch is in the trans on manual transmission vehicles.)

My switch was broken at the tang that moves the electrical contacts that turn the switch on and off, and the switch itself was jammed (which probably caused the broken tang) so that it wouldn't go into the Reverse position. Once I got the switch completely off the vehicle, I polished-up the contacts, added some Syl-Glide lube...but it still wouldn't move properly once it was put back together. That's when I noticed that the tang was broken.

The new switch has an additional contact to show the vehicle is in "Park", but my truck has no electrical connector for that, so it's un-used.

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The OEM number is/was 22509632. The "0" is hard to make out. I thought it was an "8" for awhile.

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The switch adjusts by sliding the ridged piece under the locking tab. It's supposed to self-adjust by putting the trans in "Park", but I had to tweak mine by hand otherwise the backup lights came on only with the shift lever pushed towards "Neutral".

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When I originally pulled the switch off the column, I pulled the switch off of it's snap-together mounting bracket. The new switch comes with a new mounting bracket. Spread the "legs" of the bracket to pop the entire switch assembly into or out of the column locating holes.

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[Jameer]

Searched the forum, and this thread was as close as I got to my issue.

1988 K1500, automatic trans. Backup / Reverse lights don't work.

I need to replace the "Trans Position Switch" which includes the backup light switch, item 3 in the illustration in the #2 post above.

My switch doesn't turn on the backup lights, and it fell apart when I removed the connector for the backup light wiring. The backup lights both work when I jumper the connection, so the power, ground, bulbs, and wiring from cab to taillights is OK, but the backup lights won't work when connected to the switch. There's no switch available locally, I have one on order but it won't be here for a couple of days. Therefore, I can't tell from the new switch how it would be held in place.

I don't see--or feel--any screws, bolts, or other hardware that holds the existing switch in position. I have the "official GM" service manual for my '88. The "electrical" section tells me that the switch installation is covered in the "steering column" section, but apparently they forgot it, 'cause it's NOT listed in the steering column section.

It's also not listed in the Service Manual Supplement, which corrected a heaping pile of other mistakes and omissions in the primary Service Manual. Gotta love "first model year" vehicles, and the documentation that goes with them.

HOW DOES THE TRANS POSITION / BACKUP LIGHT SWITCH COME OFF THE STEERING COLUMN? HOW IS IT ADJUSTED?

Thanks, folks.

So are you to jump the green and blue wires together with the plug in plugged from the NSS ??