Ok the original gas gauge on my car is 6 volts. The car is set up for 12 volts now.
It is currently not hooked up.
I need to know the following:

How do I test the gauge
How do I test the sender
If they are both good, how do I hook it all up?

I know this will involve a dropping resistor, but not sure where it will be.

Also if I use an aftermarket universal sender, can I use it with my original gauge or do I need to stick an aftermarket gauge under dash?

Never knowing how much gas I have makes me nuts, and paranoid. I can not even go to cruise night because I am afraid to get more than a mile from my house.

As usual I really appreciate any and all help. After 30 years of working on cars I still have new questions all the time, and you folks really help!

_________________
Tony
1964 1/2 Barracuda
Slant Six 225
(my dream car)

You should have a voltage regulator that gives 5 volts to the gauges, they need a fixed reference voltage and the regulator takes care of that, it takes the 12V as input and give 5 volt on the output.

If the temp gauge works (unless you have a light) you should have a working regulator in there.

http://www.allpar.com/history/mopar/electrical2.html

Not sure what you mean with the 6 volts gauge ? we are talking about the 64 right ?

On some models the regulator is on the back of the instrument cluster and on some it is built into the gas gauge (you should have your on the back of the cluster).

A resistor will not be a good solution because the voltage will not be regulated, the 12V in your car are not always 12V volts, it changes, and this would be reflected on the output and as a result you might damage the gauge or the needle will move with the voltage changes (happens with the crappy original regulator to some extent also ;o)

If you use an after market sender it must match the gauge if it is going to work, otherwise you must modify or replace the gauge.

No actually this on a 52 Chrysler Windsor with an 89 Dodge 318 in it. Luckily i can get to the sender from the trunk. No need to drop the tank.

_________________
Tony
1964 1/2 Barracuda
Slant Six 225
(my dream car)

Ahhh!

Then you might find this one helpful, it's for Imperial 52 but should not be much different.

http://www.imperialclub.com/Repair/Lit/ ... /index.htm

You could use an electronic voltage regulator, very easy to install, one of the 7806 models, I don't think the gauge use much current, it's the same idea as they used in the previous URL but you use a 7806 instead of a 7805.

The alternative is to make a voltage divider
http://en.wikipedia.org/wiki/Voltage_divider

If the two resistors are the same size you will get 6V out if you have 12V input, just make sure the resistors can take the current, but as I said, the fuel gauge should not use much I think.