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I'm rewiring 53 chevy 1/2 ton.It is converted to 12 volts already. Found a componet about 3/4 diameter by 2" long. one end is connected to amp gauge the other was not connected at all.Does it go to gas gauge? Gas gauge was not working before it started to rewire. There is a number on it. 7257919, .5MFD, 200V.D.C. What ever it is do i need it? And how do i test it?

Odd, that appears to be a .5 microfarad, 200v capacitor. Not sure why you'd have one of those connected to the ammeter. (Capacitors block DC voltage.)

If you're using the stock, 6 volt gauges, you will need resistors to reduce the voltage to 6 volts for the gas gauge. Randy Rundle, who is the Garage Foreman here, sells a Runtz voltage reducer which will do the trick. Don't recall the price off hand, but you can find a link to him on our Links page. You can also just go to Radio Shack and buy a proper resistor (but I don't know what values you'd need.)

I have heard of people using capacitors as noise filters for radios and stereos. Maybe the capacitor was used for something like that?

Sounds like someone's attempt at a filter capacitor to eliminate static in the radio. Used to be able to buy one from JC Whitney that was about 6" long, worked best if mounted near or on the generator. I put one on a Mack that I drove, it did help with the CB.

Thanks everyone for the help. Can you advise how to check the gas gauge in case it did burn out?

Here's how the gas gauge system works:

• You have 6 volts going to the positive terminal of the gauge.
• The negative terminal is wired to the float in the gas tank
• The arm of the float has a needle that rubs across some windings (called a potentiometer)
• When the float is high, there is some resistance to ground
• When the float is low, there is very little (if any) resistance to ground

So, you can put 6 volts on the + side of the gauge and then ground the negative side. Then remove the ground. In one position, the gauge should read full, in the other it should read empty.

I did indeed design the Runtz voltage drop for gas gauges. Just for the record The Runtz is solid state and also has some built in circuit protection to protect your dash gauges in case of an electrical malfunction. The other advantage to the Runtz is that it accepts a range of voltage between 8 and 20 volts while still providing a constant regulated output. This helps if you are running a generator. Normally the voltage changes that occur within a generator system will cause most all solid state accessories fits. You might want to keep that in mind if you plug your cell phone into your cigarette lighter if your truck is generator powered.. You might have smoke leak out of your startac!! Wouldn' that be embarrasing!!