Water Temp operation by itself. How to configure

Nope.

The power for the temp gauge comes from a voltage regulator built into the gas gauge via that copper strip. It needs 5 volts.

You 'can' just make up a small electronic voltage regulator to power up the gauge, they are pretty easy to make if you know how to solder.

Here is a good link on how the stock gauges works:

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

William Oliveri wrote:

So if I under stand you correctly I the voltage regulator would drop 12 volts down to 5 to power the gauge. Is this correct?

Is so It would look like this:

12v source -> 5v regulator -> To pole on temp gauge opposite sender pole.

Yes?

Thanks,

Bill

Yes.

Here is a link on a regulator:

Well, the fuel guage and the temp guage both use the same 12v source. They are grounded through the respective sensors. So, if you took the 12v away to feed the fuel guage, you need to make a jumper of some sort to get that 12v back to the temp guage.

You could also take a 4.1kohm and a 5.8kohm resistor (or a 41k and a 58k) and tie them in series. Tie the 58k end to +12 and the other end of the 41k to ground. Grab approx

5 volts from where these two join.

I don't know how picky these gauges are about their 5volts!! But note that

+12v isn't exactly clean.....so maybe a capacitor in parallel might smooth it out!

SB did pass the time by typing:

Much better solution.

7805 Voltage Regulator (Radio Shack 276-1770)

Takes any voltage from 6 to 35V and gives you a rock steady 5V at up to 1A.

You only need three wires, voltage in, ground and voltage out.

CJ gauges use 5 volts, not 12.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

CRWLR wrote:

They are pretty picky. Your method would rely on alternator output with no regulation and the gauges would go with the rpm or lights or...

Mine has a punky rivet connection on the board inside so I sometimes only get 3 volts and my gauges act accordingly.

Mike

SB wrote:

I thought there was a rectifier in the alternator to keep it from going way overvoltage. The battery acts as a filter to get rid of a lot of that AC stuff.

But I agree....a separate regulator is what I'd use....