The Stovebolt Site Forums The Shop Area The Electrical Bay Gas gauge 12 volt

Our 54 3100 has all its original gauges. They all work except the gas gauge. The trucks been converted to 12 volt. The PO took the sender out of the tank and threw it away. From what I have read it's a 30ohm that's what I ordered and instead of using a runtz I purchased a 12volt gauge quadrant. Is there anything I need to know about installing this gauge that will make it easier? I see a hole in the floor with a grommet is that how the wire is routed to the gauge? Gas tank is behind the seat any help is always appreciated and thank you. Steve

Don't trust that the tank is grounded to the truck. Run a dedicated ground from one of the sender mounting screws to the cab.

Thanks that's a real good tip. The tank is on some kind of tar paper so that may effect the grounding. I'll run a separate ground wire.

I have a 54 3100 I just completed replacing the gauge with a 12v gauge and replaced the sender. Yes, my sender unit wire goes through a hole in the floor. My gauge had some strange behavior until it was completely installed and the ignition turned on to apply power to the gauge. Ground is critical, as cletis pointed out.

Wow....I never realized ground was so important for these gauges. After the wire goes through the hole how did you route it to the gauge? Also what was your technique for installing the gauge quadrant ?

Reality is .......ground connection..........is critical in every circuit, not just gauges.

You are most correct...I have grounded myself out on a spark plug....it was shocking to say the least! You only do it once.

Yep, I touched a bare connection from the coil and it slammed me against the one.

One time is one more than enough.

How is the cab grounded to the frame/battery? Cab mount bolts?

Got that covered two grounding straps cab frame and starter battery...my 90 year old uncle had me do that he said it was the thing to do back in the day. ...Carl you haven't mentioned any secrets to putting in the gas gauge ...come on give them up!

Who,
The factory location of the fuel sender ground is the bottom of the cab (outside of the cab) under a wire clip held on by a nut and bolt (the bottom of the cab originally may have had some red oxide primer if any coating at all). Since the cabs originally did not have a ground strap going to the cab, I am guessing that the cab mount bolts provided the cab ground. Fast forward 60 years, where we epoxy prime and thoroughly paint every part to prevent rust, we may be losing adequate cab grounding.
As far as "secrets" to putting in the gas gauge, it helps if you have extra elbows in your arms.
Carl

Thanks Carl...no xtra elbows and a fat head to boot! Looks like hell under there ...maybe it's a job for a younger mechanic with xtra elbows and a back that can bend! I'm in my rusting years!

A suggestion on working under the dash might help? One of my buddies suggested I build a simple plywood platform with a thin pad to span the floor board area. It worked like a charm for laying on my aching back while fixing a rats nest of wires a PO had made. It was comfy enough, I might have even bagged a few z's a time or two.

Hey now that using your head to save your back? Plus you can bag a few zzz' and the wife will never know. Just looking up into all those wires will give you nightmares though....l