TESTING A TEMP GAUGE

[WILLYSMB]

Hi, after all my rewiring and fussing with my truck. My temp gauge still doesn't
register above cold on the needle in the temp gauge. Is there any way of testing the gauge to see if its shot and if so how?:confused:. Also whats the alternative to the temp gauge they seem too be quite expensive to replace. My gauge set-up is for a 1972 series III with the temp and fuel housed in a single unit with a red charge light located in the bottom center.

help :D

Marshall

[thixon]

If you don't care about original, go buy an aftermarket gauge at your local auto parts store.

[KevinNY]

A VDO brand temp guage and sender with actual numbers on it. Mount it in a VDO single guage pod on the side of the dash or the center dash console. You can also mount it next to the oil pressure guage, there is a cut out already in the steel behind the dash padding.

[siiirhd88]

You can check the wiring diagram from our host's site at:

http://www.roversnorth.com/store/pc-260-276-page-84-electrics-circuit-diagram-series-iii.aspx

The power to the fuel and temp gauges is from a green wire off of the fuse box (fused circuit, ignition 'on'). This green wire supplies the voltage stabilizer, usually mounted on the rear of the fuel and temp gauge cluster. The green wire has a male 1/4 spade connector that plugs onto a female spade on the stabilizer. There is usually one light green outgoing wire (1/4 male spade, plugged onto a female spade on the stabilizer) from the stabilizer that plugs onto the fuel or temp gauge, and jumpers to the other gauge. If the fuel gauge works OK, check to see if the jumper wire is connected. From the temp gauge, a green wire with blue tracer goes to the temp sender on the cylinder head. This wire has a 1/4 female spade connector at the temp sender. The temp sender varies the resistance to ground as it heats up, changing the temp indication. To check the temp sender wiring circuit, unplug the wire from the temp sender and ground the end of the female wire connector. The temp gauge should peg hot. If the gauge pegs hot, replace the sender. If not, check the circuit connections. Or, your gauge is shot.....

If your Series is like ours, the previous owners could have been very creative and replaced the factory wiring with anything.

Bob
'96 Disco SE7
'80 SIII 109
'75 SIII 88 V8
'68 SIIA 109 V8
'6? SIIA 109