Electrical nightmare!

Damn that new fangled 80s technology! My MFA and economy guage are desperately temperamental. Here are my problems:

Economy guage: works only in 5th. The light rarely/never works but some days seems to be fine! I've heard mumblings of the leads being related to the reversing lights, and something was mentioned about only 1 reversing light working when I had an alarm fitted, but alas I haven't checked yet.

MFA: just about everything seems OK apart from the external temperature guage which reads a constant 45 degrees. Probably a sensor but where can I get a replacement?

Other problems: indicators sometimes flash to fast, but not always. Rear heated window doesn't work but the switch is fine (light comes on).

I'm hoping that everything bar the temperature guage is related to one problem…but maybe that's optimistic. Any ideas?

The economy gauge only works in 5th so you are OK there!     My upchange light flickers very rarely and I?ve tried another relay with no joy. According to one of the other posters there?s a thing you can twiddle near the dizzy. When the weather is warmer I?m going to twiddle to see if it fixes it. :roll:

Yes the econ gauge and reverse light use the same switch block on the gear box, but different switches of course.

The temp sender is under/inside the drivers (?) side of the front bumper. Try GSF or VW for replacement. Mine usually read OK or -31, I?ve tried a second hand one with no joy. :cry:

Indictors and rear screen, clean up the earthing point under the rear boot mat. Infact clean up all earthing points, battery, chassis leg, engine, rocker cover, rose next to fuse box etc.

Use a mulitimeter to test 12v is getting to the rear screen. On MK11s the wires break in the rubber grommet between the body and hatch but I?ve never come across a MK1 with that problem but worth a look.

Again use a multimeter to check the none working reversing light.

Anybody trying to solve electrical problems without a multimeter are wasting their time. They are less than ?10 and should be issued as standard to all MK1 owners.
 

Thanks a lot mate! I wondered about the economy guage only working in 5th but the other problems made me paranoid!

Will clean all the earthing points tomorrow and order a new sensor

Whereabouts is the little twiddleroo?

Also have a look at the wiring which comes out of the top of the rear hatch. Don't those go to the rear screen.  They can break inside the rubber gromits.

Yeah I checked that, it looks clean and I don't think that it's causing the failure. I'll get a circuit tester to check everything though