The Stovebolt Site Forums The Shop Area The Electrical Bay Suggestions for tracing my gauge lights not working - 55.1, C3100

HI All
I finally drove my 55.1 during dusk for the first time and noticed my gauge lights are not working ( shift by engine sound, and know my speeds from the wind sound, so I was OK, a little uneasy, but certainly drive-able). The gauges are stock, and all but fuel gauge work. The headlights (normal and brights), blinkers, brake and parking lights all work ( first pull out of switch lights up parking lights, second lights headlights) - and I have attempted to turn the light switch both clockwise and counter clockwise ( manual said gauge brightness was counter clockwise). No luck on the gauge lights no matter what. I am assuming for the moment that the chances of both gauge cluster bulbs being burned out is certainly one possibility, but wanted to ask for some other things to check. I looked up the headlight switch for my truck at LMCtruck, and they show 3 types of switches, including original OEM type. My 55.1 was originally 6V, and has been converted to 12 - So far, my research shows original OEM switch appears to not be bothered by 12V

Any suggestions would be welcome, otherwise, I have to crawl under the dash and have a sore back for a few hours to look there - thanks to all who respond!

Joe

Joe,

Did you change your gauge light-bulbs to 12v?

The original 6v rheostat/switch will work OK with 12v.

Hi Tim
I was not the one who did the 12v conversion, but I am slowly making changes to the electrical system. For example, the coil has no ballast resistor, so Perhaps the gauge bulbs were left from OEM - I did change one of the blinker bulbs, and it was a standard 1157 Amber turn signal bulb that even had dielectric grease on it, so this conversion is definitely a mixed bag so far of things done well, and things neglected/wrong

I have been quite busy since my initial post, so I have not had a chance to look at them. Heck, I have not taken a look where the bulbs are yet, so I have to start there

Thanks for your suggestion - I am hoping it is a bulb issue, that is easier than pulling out the old switch

Joe

start with the bulbs, if they are Ok, then look at the switch. There should be a separate lug or terminal on the switch for the instrument lights (they are the only ones that dim). You also need to check the rheostat on the switch (looks like a round spring on the front, right behind the dash).

There should be 2 bulbs to each gauge cluster( 1 each left and right side), plus 1 that lights around the ignition switch. Unless left 6v cant see all 5 blowing together.
I'd check the switch one the terminal that feeds the lights. Don't have diagram with me right now but I think it was centre top or dash end terminal on top the switch.

1954 truck light switch - should be the same on 1955-1st series.

Hi 52Vff and TClederman
Thanks for your replies - life kept me away from here for a while
I was thinking the same thing that it would be unusual for all 4 bulbs to go, but I also took a look at that light switch and almost pulled my back trying to contort to even look behind the dash - lots of room behind the dash, but man I cant bend the crazy way to even see it - I looked it over as best I could with a mirror for now to see any obvious problem.

I am wondering a couple things here now

1) I wonder if I can unscrew the pull knob and nut on the cabin side, push the switch through and hope that there is enough slack to drop the switch and look at the connections - bad idea?

Where is the bulb access on these gauges - I could not see any sign of the bulbs from the front?

Thanks for the diagram as well Tclederman - that was quite helpful as well

All I can say is, disconnect the negative cable from the battery first. Lots of things back there are wanting you to let the smoke out of them.
Well I guess there is more I can say...
There is a spring-loaded button on the light switch which allows you to pull the knob out. Push the knob in all the way first. Then you remove the chrome bezel with a large screw driver. You should have plenty of slack in the wires to pull the switch out to look it over.
Carl

The bulb sockets are held into holes on the forward side of the gauge housing by spring clips. Grab ahold and rock to one side and it will come out.