E30 Zone

Having issues with temp gauge. Gauge bounces up and down when putting load on the car as in hazards heated screen heaters all causing gauge to rise and fall. Making me unsure on temp of engine. M20 325. Any help appreciated

Have you checked the nut on the back of the clocks?

Yes should of said nuts checked and washers cleaned.

give the dash a good hit above the temp gauge ..

Tried wacking have had clocks out and don’t believe it’s a loose connection. Interested to no where earth points are for dash wiring. Or can dodgy alternators cause strange things like this?

I reckon I'd have a loose connection if I kept "wacking my cocks"

paultv wrote:I reckon I'd have a loose connection if I kept "wacking my cocks"

Mart.

The Earth for this is along the drivers door edge , there are 4 Earth points on these dashboards, under the dash on the drivers side, along the frame on the passenger side and behind the glove box there are 2.

With these cars now well over 30 years old I would suggest checking the resistance of the cable from the dash (Brown/Violet - If I recall) all the way to the temp sender. A dodgy connection on the brown plug could also be the cause as the wire tends to break on the bend before it goes into the connector.

There is only one earthing point behind an E30 dashboard, although on cars with extras that increase the number of leads connected, some of the wires may be connected to a short bar with a second stud, fixed onto the first stud.
There is also an earth for column stalk leads to the top f the steering column, whih eventually earths to the body through the steering column lower bearing.
Any other earthing points you may come across weren't put there by BMW.
The main failure point for the temp. gauge wiring on post facelift M20 cars only, is under the lower rubber cover of the injector harness to engine loom plug and socket under the inlet manifold.

Spot on Brian. However, I cleaned the earth on the drivers top suspension mount and it cured my gauge fluctuating whilst under load.

Mine was cured by changing the earth strap between above Hem sump and leg.