Today I was driving and noticed that my temperature gauge had suddenly stopped working. I drive a 1987 Wrangler and I'm proud to have one. What I am wondering is where the sending unit is(So I can Work on it) or what could have caused this problem any insight would be great.
ok, got it fixed. first tried grounding the original wire going to sending unit, this should have pegged the guage if guage was good and the wire wasnt broke somewhere between the sending unit and guage cluster. nothing happened so i spliced into solid purple wire on guage cluster and tried grounding it, the guage pegged so i ran the new wire that i spliced through the firewall spliced it to the boot and reconnected. works fine now.
this is from a post i had up when mine quit working.
the sending unit is on the back of the motor on the drivers side on top next to a head bolt. should have one wire with a rubber boot connector.
if you have any problems let me know, maybe i can help.
If it's anything like mine (none of the gauges worked when I bought my 90; the temp and oil pressure gauge worked only intermittently), this is an easy fix.
I removed the cluster, removed the gauges, cleaned all of the terminals to remove corrosion, then replaced everything (dielectric grease!) and made certain that the connections were good and tight when I reconnected everything. Everything's been kosher for a year now.
Also, keep an eye out for shorts on the plastic circuit board on the back of the cluster as well - I had to replace mine due to a couple of shorts.
thanks for the help, i plan on cleaning the contacts since that seems to be the problem (it worked for about 10 minutes of my drive to school) so i know the sender and gauge work i guess its just dirty being 20 years old and all
I'd bet that solves your problem. Don't overdo it, but also don't be afraid to make the nut holding the circuit board to the gauge nice and tight...mine felt good at first, but it turned out they needed an extra turn or so.
I have a little bit of info to add to this thread. I also had intermittent temp, gas and oil pressure on the gauges. I took the gauge cluster out and removed the nuts on the back of each black plastic terminal plug. When I removed the plugs I found some corrosion at the base of the posts where the plug makes contact with the terminal on the circuit board. I cleaned all the posts and contact points (essentially every brass part that touched another brass part) with a scotch brite pad. I also got to thinking about what might be going on inside the plug holes in the back of the gauges. I shined a flashlight inside the holes and it looked pretty corroded. I took a Q-tip (white cotton ones not plastic) and cut off one end with side cutters. I then twisted the cut end into the hole in the back of the gauge and it came out pretty black. Be careful you don't twist the Q-tip off in the hole, just a note even though they are very sturdy. After cleaning all the holes I put everything back together with dielectric grease and the dash works great. No more bouncing gas gauge and intermittent oil pressure. I don't know if this has been covered before but it won't hurt to mention.
I have another post about this very thing, but my gauge stays pegged. I just replaced the sensor and I still have the same problem. If the gauge is pegged, i have to assume there is a ground, but where?
The purple wire is grounding out. As someone else mentioned you can use barrel connectors and run a new wire in place of the purple one. Or try tracing the purple wire to find a burn or cut. If the sending unit wire touches metal, it will cause the gauge to peg out. And by the way if you replaced the sender with a parts store version like autozone the temp may read 30* hotter than actual temp once you fix the grounding of the wire. If it reads hot then return the sender and pick up one from a dealership. Autozone and advanced senders all read 30 degrees hotter than actual temp.
If you need a new circuit board, they sell them on ebay for 79.00$. They claim to be improved over the original. I purchased one myself, but haven't installed it yet. I'm redoing my whole dash with new bulbs, circiut board, heater controls, glove box, paint and stereo.
1987 wrangler, 258 I-6, 5-speed.
2007 liberty sport 4X4, automatic
2009 ford ranger 4x4 FX4 OFF/ROAD, 5-speed
Thanks for your post, I have a 91 YJ and my fuel, oil, and temp gauges started dancing and not working right. I'm going to take your advice, pull my cluster and clean and check all the contacts. I'll also use the dielectric grease, I think I have some laying around that I bought for spark plug leads.
Im having a problem with my temp gage only got up to 110 degrees. I used my IR thermometer on the engine and it read 180. I cleaned all the gage contacts and it still does the same thing. I was going to try an new sending unit but not sure if that is the issue. Any suggestions?