Where are the earth connections?

[Tacchino]

I'm trying to diagnose a lighting issue - they're pulsing - that effects headlights, interior lights etc
I'm guessing that it's caused by a voltage fluctuation.
Pulsing only occurs when engine revs are above about 1200 rpm.

The car has just had a new alternator fitted and the supplying / installing dealer is suggesting that the problem is related to an earth at the rear of the car ie. the bit they didn't touch!

Does anyone know if there's a big earth at the back end or just a collection at various places within the boot area that earth different items?

My thoughts are that the alternator is a bit iffy but I'd like to cover as much as possible before going back to the dealer with the old grumpy head on

[Tanguero]

Front nearside chassis at the back of the wheel arch.
Engine block nearside down by the oil filter.
Inside the passenger compartment behind the panel with the immobiliser plug thing. (This is a swine to get to!)
In the boot above the fuel tank slightly to the offside, behind the control boxes.
There is a main earth connection to the fuse panel as well.

I think that's all of them.

Its always worth checking the big fuse - its only in the alternator charging circuit but may possibly be related to your symptoms only occurring at certain revs. Its at the back of the engine in the V behind the coil packs.

Edited by Tanguero on Friday 8th July 20:13

[mikesr]

There is also one on the top front cross rail by the radiator fans.

[Tacchino]

Thanks guys, I'll get checking this lot through.

The big fuse and holder was replaced when the alternator was fitted so, hopefully, that shouldn't be the problem.

Now, where's me hammer

[Tanguero]

mikesr said:

There is also one on the top front cross rail by the radiator fans.

Ha - forgot that one!


ETA. If you connect the diagnostic software, is the pulsing showing as a fluctuation in voltage? If so my guess would be that its something that the new alternator is doing.

Edited by Tanguero on Saturday 9th July 02:36

[petelem]

mikesr said:

There is also one on the top front cross rail by the radiator fans.

What is connected on here?

[mikesr]

That's the earth that I thought was on the cross rail. My memory isn't what it used to be :-)