Gauge Lights Won't Come On - Help Please

[Gregski]

74 GMC half ton

headlights come on but gauge lights do not, I pull the headlight switch out twist it left and right and nothing, do it with both no key in ignition and with key in ignition in all sorts of positions, nothing

replaced all six bulbs

replaced all 9 fuses

tested light bulb under dash it is a good one (not related but would want that one to come on too)

removed headlight switch cleaned and rebuilt it (dont know how to test it)

dont know how to test with a multimeter or where to start, which wire is the power for those darn cluster lights?

advice needed

[77K10Silverado]

Prob a bad printed cluster circuit. I had a bad one that acted like that. Changed it and everything lit up!

http://www.classicparts.com/Wiring-H.../products/368/

[Cabnchassis]

Mine has a short or something but will usually come on if i mess with the dimmer a little.

[walkerb]

I had the same issue. Bad headlight switch. Things worked just had a bunch of corrosion on it.

[Gregski]

Originally Posted by walkerb

I had the same issue. Bad headlight switch. Things worked just had a bunch of corrosion on it.

Thanks, gonna pick one up at AutoZone today for $15 bucks, I was taught long time ago to replace the easy/cheap stuff first, even if it ends up being the printed circuit, that thing is $70 bucks, so hope the switch is it, that would make The Greg happy

[HEADTURNINGC10]

Do your tail tights come on? My brothers truck is currently doing the same thing (1980 gmc sierra) but his marker lights, dash and tail lights arent coming on only the headlights come on when pull out the the switch.

[Gregski]

Originally Posted by HEADTURNINGC10

Do your tail lights come on?

Yes, in my case my tail lights do come on

[swissarmychainsaw]

Originally Posted by HEADTURNINGC10

Do your tail tights come on? My brothers truck is currently doing the same thing (1980 gmc sierra) but his marker lights, dash and tail lights arent coming on only the headlights come on when pull out the the switch.

GM did this on purpose. If you blow your fuse for your tail lights, you'll know it because you dash lights stop working.
Least that's what Dad always said, and he worked there for 30 years!

[Gregski]

found this very helpful post

http://67-72chevytrucks.com/vboard/s....php?p=5190913

[Dead Parrot]

Headturning - check the fuses in your bother's truck. Made a 100 mile trip at night thinking just my dash lights were out. Instead, much like your brother's truck, its was dash lights, and all running lights. Brake and turn lights worked, headlights worked as did the dome light. It was a 68 Impala but I am guessing GM didn't change much on the wiring between the two. Replaced the bad fuse, all lights lit again.

[Gregski]

after replacing all the light bulbs in the cluster and all 9 fuses in the fuse panel and installing a brand new headlight switch, it was time to yank the printed circuit board

check out my light bulb testing station, a simple 9 volt battery I think is what helped me find the problem...

"just doing the dishes honey, go back to bed!"

[Gregski]

I honestly think the problem was:

1. dirty filthy cluster, circuit board, connectors

2. the light bulbs have these tiny wires sticking out where they need to make contact with their black sockets, well those wires were too pressed in on the bulbs and the contacts in the sockets were too spread out from years and years of pressure

Solution: I unbent the connections on each light bulb very carefully until they made contact, even had to do that on the brand new bulbs, on some of them I bent the wires in the opposite direction to finally get those bulbs to work

I used electric parts cleaner and dielectric grease in all the bulb sockets

[Gregski]

The pictures above show me testing each step of the way, I finished putting it all back together close to midnight so I did not snap any more pictures, I did have more than the four bulbs glowing including the one that is missing in the middle of the cluster which I inserted later on

my advise, is take your time, have a beer, listen to music, work in good lighting, like at your kitchen table, LOL its a labor of love, thanks again for all the advice please check out my Restoring Rusty thread for other progress

http://67-72chevytrucks.com/vboard/s...d.php?t=645440

[walkerb]

Glad you got it working