Temp Gauge not working

[92REDXJ]

i searched a bit and couldn't find anything so here goes...92 XJ 4.0 HO auto tranny, just replaced the head gasket for the 2nd time, first time doing it i was stupid and screwed up, replaced it and its great now, everythings fine, except the temp gauge doesn't work. I replaced the temp sender unit the first time i did it, but it might have been damaged on the 2nd time. I checked the continuity on the wire and it has continutiy, and everytime i turn the ign. on the gauge goes all the way to hot and then goes back down. any ideas?

Zack

[92REDXJ]

ttt

[Saudade]

If the engine is hot, it will show a relatively low resistance (under 1000 ohms). If the engine is cool, it will show a relatively larger resistance (over 1000ohms) . Either case shows "continuity".

How soon does it go back down? How far down does it go?

Maybe you whacked the wiring when you pulled the head.

[JeepFreak91]

pull the wiring harness off the sensor and see if its leaking coolant out of the top of it. thats what happend to mine we had to get another one to replace the one we got to replace it because it broke when we put it in.

[cklaus]

also make sure that u properly filled and "burped" the coolant system of air. a temp gauge won't read if it has an air pocket around it.

[92REDXJ]

hmm haven't thot of the air pocket....its not leaking coolant out of it, and what do you mean how soon it goes back down....when i start the jeep the needle goes all the way to hot and then drops all the way back below 100.

Zack