Hi
My 90 failed it's MOT on an earth fault. What's happening is when indicating the side lights are going dim then normal. I've tried earthing out the indicators separate and even taking the bulbs out. This causes the side lights to go dim and normal quicker because The indicators are now not working right.
Here's the first problem. Second earth problem I have is that when I put my fan on it makes the temp gauge rise, put my foot on the brake and same thing.
It's had a 200tdi engine fitted in place of the 2.5na engine because I had one spare from another project. Someone I know fitted it for me, but I can't see an earth from engine to chassis. I did used to be able to see it on the old engine. I think it went from sump to chassis.
So the question is, if I fit an earth cable from the engine block to chassis will this solve my problems? If t will where's best to do it to and from?

I can't remember if it used to do this on the old engine, it isn't too bad I don't think, the side light isn't going on and off it's just dimming then coming back.

If it isn't this earth where else do I need to look? Help before I set fire to it!!!

stick jump lead from neg bat to engine block and see if your probs go away.

either way stick strap from engine to chassis, chassis to bat, i'd also stick one from gear/xferbox to chassis.

What he said.

Also check the handbrake cable hasn't had it's insulation rubbed off, which might be creating an earth/short point across it! (Or was that just the Disco's?)

Each sidelight and indicator has to be earthed separately to work well .. there's a metal tab inside and this needs to be connected to metal via the self tapping screws that hold the light body on. Without a decent tight thred connection this can produce similar faults to those described.

Thanks for the reply
I ran a jump lead from negative on battery to engine block and nothing. I then ran one from engine block on the sump to the chassis. It sparked when I did this. Still no fix.
Any other ideas?

With regards the light earth, one front indicator has a desperate earth because of another fault that came up. I earthed the back on the same side with another wire, and took out the screw that earths t through the mount(without this screw in the indicator stopped) and still no fix. They are flashing all lights aswell not just the side indicating if that makes any difference.

Cheers

go do bat neg to chassis and chassis to engine when ign is off. so you are using both jump leads.

it shouldn't spark.

then ign/engine on turn fan on and see if the gauges are fixed. if not on engine bay side bulkhead to the right of brake servo there is a wire coming from the inside of the dash that should be bolted to the bulkhead. this is your dash earth. undo, clean up and reconnect.

check again.

have a good look at what earth straps you actually have