The Stovebolt Site Forums The Shop Area The Electrical Bay Fuel Gauge (Smoke)

What did I do wrong I replaced the non-working 6V fuel gauge with a new 12V gauge and when I put the battery cables back on and turned on the switch the hot lead to the fuel gauge burned up. Any idea what happened or what I might have done wrong to cause this. I hooked up the 12V gauge just like the 6V gauge I took out so just not sure?
Thanks

Mike, Three things...

1. What kind of truck do you have?

2. You should check your wires to ensure that they are not grounding out. I would recommend running new wires.

Next, come off your fuse box with a hot wire (one that is keyed) to the IGN side of the gauge Then, take the wire from your sending unit and connect it to the other side of the gauge SENDER. If you get these turned around you will burn up your sending unit. To go a bit further, i would make sure your tank is grounded well to the frame.

3. When you installed the new gauge in the housing check to see if it's touching the housing and grounding out (HOT LEAD). This could be why it's shorting out and smokes.

Jeremy

It sounds like the hot lead shorted to ground. There whould be a fiber washer that insulates the connection.

Thanks for the info guys I have a "54" 3100 it seems the only wire that smoked was the hot lead from the ignition switch to the gauge not sure how you would prevent the gauge from shorting to the housing the studs just come through the metal housing so they are touching, the back side of the gauge is touching the housing there is a cardboard divider that goes on the studs after they come through the housing but it does not prevent grounding? All I did was remove the 6v gauge and install a 12v gauge what happened?
Thanks

Mike, I'm all out of answers. It appears you done all the correct things to prevent contact. It may be a faulty gauge.

Jeremy

I haven't had a '54 Chevy apart in a while but it sounds like you are missing some insulation. Those studs can not be touching or your hot wire will be straight to ground.

Any one that has switched out there fuel gauge recently give me any idea of what I am missing on mine. Insulation, gasket, what keeps the gauge and studs from grounding to the housing? Pics would be great if possible.
Thanks

mperk,can you post some pictures of your setup and installation ?

Mike, Pics would be great. I just rebuilt two '37 and one '53 Chevrolet gauges(all componets) and wired the trucks with no trouble. If you post a pic we may be able to help you figure out what's going on. Are you using the old wiring harness?

Were here to help...

Jeremy

While we are on the subject...I'm almost finished rewiring my '53 GMC to 12v. pos. ground but don't have the gas gauge hooked up yet. Can someone tell me which post on the gauge goes to the tank and which is hot? I don't want to fry my old gauge. Thanks.

Well, there are two studs and the frame is grounded to the dash. The power stud supplies the power to one movement coil directly and suppies power through a second coil to the sender. So, measuring the resistance to the unit frame from each stud separately should give two dufferent values. The one giving lower resistance value is the power lead.

Well I think I figured out my bone head mistake, put the new gauge in and put the insulator and bolts in the wrong sequence thus a really nice smoke show so now I need to replace the wire from the switch to the gauge can someone tell me what size wire that is? It appears to be either 14 or 16 but not sure.
Thanks

Mike, a 14 GA wire will be fine. I'm glad you figured it out. When i rebuilt my 37 amp gauge, i had a hard time getting the dang thing centered as it don't have the tabs to line it up. About, an hour later and two 800 MG Ibuprofen I finally got it right.

Jeremy

Thanks guys for all the help. Once the smoke clears and you realize you did not just burn the whole truck and shop up you want to just kick yourself in the arse for being so stupid and not putting things back the way they came apart. Oh well the more I do to this truck the more I learn. 2nd one should be really easy!!!!!
Thanks

Mike, you're right, the second one will be so easy you will wanna do a third.


Jeremy