temp guage

[scoutman]

Been working on making a 1984 318i a reliable car for my son. When he bought it there were some cooling issues. I got those straightened out with a radiator, thermostat and fan clutch. All was good until recently, the gauge stopped working. It stays at the bottom and never moves up. all other gauges work fine and I cleaned the nut on the back of the cluster. I am guessing the sending unit has gone bad.
On the upper hose housing there are 3 different electrical units. Which one controls the gauge? I think it is the one with 2 spade connectors, but want to be sure before buying a new one.

Thanks

[ak-]

My guess is #8

http://bmwfans.info/parts/catalog/E30/2-doors/USA/318i-M10/LHD/M/1984/browse/engine/cooling_system_thermostat_water_hoses/

[FLG]

Its the one connector one, brown iirc. If you ground out the wire going to it your gauge should sweep to full, if it dosnt problem lies somewhere between the gauge and the connector.

edit: http://www.pelicanparts.com/More_Inf...0%281987-91%29

[vpilarrt]

ak- is correct. Sorry FLG, but you have the wrong part, it doesn't even go into the '84 318i.

[jlevie]

A bad SI board can cause this.

[FLG]

ak- is correct. Sorry FLG, but you have the wrong part, it doesn't even go into the '84 318i.

My apologies I didn't see the 84'

Sent from my Galaxy Nexus using Tapatalk 2

[Gregs///M]

Its usually the brown sender with the single pin in the connector. However, there were a few different colors.

Also, Jlevie is correct. Dead SI board will most definitely affect the temp, tach, and MPG gauges and sometimes not at the same time.

I'd replace the sender first, then consider an SI board replacement.

[scoutman]

Thanks, I sorta thought it was number 8 in the diagram. I will pick up a new one and hope for the best. I already swapped out the circuit board. The batteries had corroded and leaked, corroding the imprinted circuit for the instrument lights.

Nick