Hey guys, I've had nothing but issues with my gas gauge ever since converting to 12v on my '53 Chevy. It works intermittently. My last attempt at fixing it showed 12v at the "in" side of the runtz but 0v at the out. Clearly this is an issue. Do they burn out? Thanks, Carl
Any resistor will burn out if you exceed it's power rating. If you are only using it to run your gas guage, it shouldn't have burnt out unless the ouput was shorted directly to earth.
If you are only running the gas gage it may be a simple fix to use the LM7806 electronic voltage reducer. I run one on my 37 Chevy and the gas gage works great. Few $ for the part and basic wiring work and your gage will be receiving 6v supply. Only drawback to the electronic voltage reducer is they have about 1 amp capacity, so good for gages, not good for heater fan or old 6V radios.
odd that you have this problem, a buddy of mine also has a '53 chevy converted to 12 volts and has burnt out 3 of the LM7806 regulators...can't understand why, only running the fuel gauge. And they are mounted on heat sinks.
"FORD has a better idea" up through the 80's ford used 6 volt gauges with this:http://www.ebay.com/itm/360928515943?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT This Mustang unit took care of the whole gauge cluster.What gauge wire are you using for your ground at the sender? and what gauge from the sender to the gauge? Make sure the ground is attached to clean bare metal on the frame.
i had a customer try to jump start his truck but hooked the cables up backwards. the gage stopped working, i had to change the runtz resistor.
I have also used an LM7806 regulator, and used that to regulate a larger transistor. I run my 6v heater fan,, gas guauge and a couple of other 6v gizmos fom it. It has a 5 amp capacity, and i built it in a box with a heatsink and small 12volt computer fan for cooling. If anyone wants the circuit, I will post it up. If you can handle a small (20) watt soldering iron, you should be able to build it.
the Ford regulators wore ok on Fords, which have thermal gauges (Mopars used a similar system), but not so well on GMs with magnetic gauges. what exactly is the voltage reducer you are using? does it look like this?
Squirrel, under that heat shrink and the alum heat sink, is a small electronic piece with three legs. One is 12v supply, one is 6v out, and one is ground. It is about 1/2 inch square for the electronic portion. Here is an ebay ad where you can buy 10 of them for cheap, or at least see the part. http://www.ebay.com/itm/10pcs-New-L...641?pt=LH_DefaultDomain_0&hash=item27dc7b8f29
i have used the ford stepdowns for years and the LM7806 regulators also with no issues, i used to pull them out of old electronic boards.
This circuit will increase your current capacity for the LM7806. Don't worry too much about the formulas, this circuit will be good for about 8 amps as long as the BD536 is on a good heatsink in some airflow.