ML500 2003 wont rev

[AdamNEUK]

I accelerated hard and develped a fault. I now cannot rev my engine above 3000 rpm and my battery goes flat overnight. I have taken the fuses out individually and still there is a spark on the battery terminal and lead when they are disconnected/connected even with the ignition and everything switched off. If I diesconnect the batetry the battery does not discharge. I have an idea it may be the camshaft position sensor.Does anyone have any ideas? Would the camshaft position sensor flatten the battery overnight if it were faulty?

Adam

Princeginge@yahoo.co.uk

 

[Ultymate]

Adam, one thing you could check is whether you have a short circuit in your alternator to do this you would have to disconnect the alternator and see if you still get a discharge at your battery when you connect it ie do you still get a spark. That said flashing a battery connection is not a good thing to do on modern vehicles as it can cause voltage spikes which can damage ECUs,far better to check with an ammeter if you have access to one. If there is an alternator short then the alternator should feel warm to the touch even after standing idle overnight. Having said all this I can't explain why your car won't rev beyond 3000 rpm, I'm pretty sure it won't be your cam position sensor, it may be a thing known as an over voltage protection relay, but to be honest I don't know for sure your vehicle has one fitted, I'm sure someone else with more knowledge of the ML will be along with more info.

 

[television]

This would appear to be an alternator problem,take the Diode pack off the rear,held on with two screws and buy a new one ,under £20 from any Bosch agent.

This is the cheapest thing that you can do at this stage, if it is short circuit it could have been pulling down the battery voltage,hence the 3k max.

Malcolm