Which bad earth causing weird MFA oil temps?

[G60 Bob 0]

There are several posts on this but none has an answer. Basically the MFA oil temp rises by 4 degrees when i switch the sidelights on and a further 4 degrees when the main beam is switched on and posts found during searches indicate its caused by a poor earth - it seems to be a common problem.

 

However none of the previous posts have an answer as to which earth was causing this or indeed anyone who has actually solved the problem - any suggestions good corrado people?

[Crasher 3]

Almost incurable, my 83 G1 does it; my 88 and 89 G2's do it etc etc

[Henny 0]

change the main earth strap from the battery... it's the one with the battery clamp attached to it which then goes to the chassis and on to the gearbox mount.

 

That'll normally sort it out... ;) (it has on all 3 of the corrados I've owned...)