R500 W251 won't turn over
Jump started to another vehicle with good battery still won't turn over.
Scanned with DS708 scan tool which showed a key fault. Reset codes and charged battery.
Has power i.e. all dash lights illuminate and other functions work, turn key to start position and nothing ,no clicks nothing?
Thought must be a fuse but cannot identify?
Any suggestions?
I guess the ECM is goosed but again I cannot locate it and nobody seems to know where it located.
As its a V8 engine its not on the engine.
have looked under both floor wells.




I'd be checking the ground wire to the starter (i think it grounds to the chassis close to the catalytic converter). They can corrode at that point which buggers the circuit. These cars are getting older and theses sorts of issues are common. I'd also be retesting yout battery under load witu a proper load tester, not just a voltage test. That could well be your problem.
Also I assume there are no EIS codes showing up? I'd be looking there if you don't get any action from the starter.
Last edited by BlackML550; Nov 23, 2024 at 04:12 AM.
I'd be checking the ground wire to the starter (i think it grounds to the chassis close to the catalytic converter). They can corrode at that point which buggers the circuit. These cars are getting older and theses sorts of issues are common. I'd also be retesting yout battery under load witu a proper load tester, not just a voltage test. That could well be your problem.
Also I assume there are no EIS codes showing up? I'd be looking there if you don't get any action from the starter.
The wiring loom from the engine goes to a junction box then disappears into the car so I checked under the left side foot well and dash no luck.







