300 electrical trouble

Got an electrical problem on my 300 110. It all started a few weeks ago, driving a short distance, it started to rain so I turned the wipers and side lights on, plus had the heater on, when the temp gauge went right into the red, so I pulled over to check everything, water was cool, and no sign of overheating. over the next few days, changed the thermostat and temp sender, and blew the rad through. Went out that night and tried again and it still went into the red.
So this got me thinking this was electrical, so I turned all lights, heaters and wipers off and the temp gauge shot down to normal.
Now my horns packed in, the wipers have halved in speed and my led side light bulbs wont work when normal bulbs do, which has got me thinking could this be a bad earth? im sure I read somewhere these led lights need a good earth??
What's your thoughts on this?
Thanks

earth fault always favourite

I'd start with the bulkhead earth behind the dash

I had a earth problem on my 300tdi, if I can rember correctly mine used to cut out when I put the headlights on.
I took the battery earth of which links from batt to chassis and gearbox and wire brushed everything ,never had a problem since

Station House said:

earth fault always favourite

I'd start with the bulkhead earth behind the dash

Click to expand...

Where about is the earth behind the dash? wasn't aware there was one there? or are you on about the one on the bulkhead near the servo?

L90 BCM said:

I had a earth problem on my 300tdi, if I can rember correctly mine used to cut out when I put the headlights on.
I took the battery earth of which links from batt to chassis and gearbox and wire brushed everything ,never had a problem since

Click to expand...

Ive checked that earth and everything seems clean, but ill fetch it off and clean the contact points.

Thanks for the replies chaps.

similar problems to me. Driving in the dark i noticed my ign light glowing slightly. turns out i have the wrong alt belt fitted, too wide and now that it is worn a bit, it is slipping. Job for the weekend, change ps and alt belts and hope my temp gauge goes back to normal.

My drivers-side side-repeater is now dimly it when I have side lights on, this is starting to become very puzzling.