trying to get the temp gauge working

I am trying to get the temp gauge working on my 86 258 6 cyl cj7. it is the temp gauge that is in the speedometer cluster on the bottom left side. I grounded out the post on the back of the temp gauge and it went all the way up to hot on the temp gauge. so I ran a new wire for the post on the back of the temp gauge to what I think is the temperature sending unit ( the small post that is threaded into the rear of the cylinder head on the drivers side). and still the gauge did not work . I know the sending unit was replaced 2 years ago. is that post the sending unit or is the sending unit the post that in threaded into the intake manifold? is there any way to check these sending units?

thanks carmine

So, you measured the sender tip to ground and it was 9-73 ohms (hot to warm)? You can put the sender in boiling water to run it through it's range. Assuming the other gauges in the cluster work, it's not likely to be the glass body.

I must admit, I put a new sender in mine and it worked for about a month, so I gave up and put in an after-market unit which is much more accurate anyway.

JimG

I ran all the tests on jeepteck for the temp gauge and they all checked out o.k. but still the gauge don't work. I guess I should mention that I have a fiberglass body if that makes a difference. thanks carmine

That gauge relies on the mechanical voltage regulator inside the gas gauge. The power comes from the metal strap between the gauges.

If the voltage regulator circuit is bad like mine, the temp gauge won't work or only show really low. I think one of the bolts for the power has a bad connection on the circuit board inside the fuel gauge on mine.

If you ground the wire on the engine head the gauge should move.

Fiberglass.... Hmmmm.....

Is your engine grounded to the dash??? The dash needs a dedicated ground wire and the engine is supposed to be grounded to this and the headlights.

I have one main ground tap just beside my fuse panel on the engine firewall. The battery, engine, front and back harness for lights, dash, ignition module, etc. all ground there.

Mike

Jet wrote:

His first test indicates that the regulator is (or was ) OK. It probably would be a good idea to ground the sender wire at the block to prove the wiring though.

Mike, Personally I would use a ten ohm resistor and connect to the block - could grounding it straight burn up the regulator?

JimG

Grounding straight is ok. Putting 12 volts to the power will fry it though.

Mike

JimG wrote: