Any electrical experts?

[25v6turbo]

My mates Renault Safrane has developed a big problem

He had it running a while ago and left it running while poping in for a cuppa,when he returned the temp gauge was sky high and the fans hadn,t kicked in...

He turned if of straight away and let it cool right down.

The following day it wouldn,t start,but turns over

Now after some time looking around he has found he has 7 volts on the engine block/gearbox/radiator

BUT he has every electrical connector disconected,injectors,starter,alternator,sensors,rad fan swich,gearbox computer etc,everything is disconnected but he still shows 7 volts! why?

He says even the coolant shows it,but the strut top etc is showing near nothing,only on the engine block etc.

Any ideas,he has swopped the ECU and it still done it 7 volts.

[Pillock]

Bad earth?

 

Block should be at zero volts, it should be directly connected to the body and hence the battery negative terminal. 

Doesn't really matter what the voltage is, if it's not zero that sounds like the block isn't earthed. Just bang some wire from the block to the body and then measure again.

 

Voltage difference could have killed something like an ECU, but equally it could just be not starting because the block isn't earthed so the coil isn't getting 12v, it's getting 12v-7v so 5v.