08-13-2015, 04:23 PM
Join Date: Aug 2014
Location: Waukee, IA
Temp Sending Unit
TJ owner, so be gentle...
A friend has an old Willy and asked me to help diagnose a problem he is having. The Willy was down for a while and is now back up and running, but, his temp gauge is not working. Note, I don't think anything is stock on this thing. It is an aftermarket VDO gauge. When the ignition is off, it sits at mid range, as soon as he turns the ignition on it heads to zero and never moves as the temp comes up (if it does move it is miniscule change.
I was reading that to test the sending unit take an ohm reading between the 2 contacts when cold then again after a few minutes of running and I should have approximately 200 ohm swing. Going by memory here, but, I only remember one contact on the sender (or did I not look close enough? I assume with one connector I would check the resistance between the connector and group, is this correct?
Any advice on diagnosing would be great, older gentleman that I would really like to help out.
2005 Wrangler X, 4.0L, 6 Speed
Zone 3" Lift - SYE Eliminator Tom Woods DS
Ford 8.8 rear, Dana 30 HP - 4.10 gears
Barricade HD Trailforce front bumper -made into a stubby
Home built rear bumper/tire carrier