Hello

Car is 1994 E 300 Diesel with OM606.910 engine.
One of the fuses on the OVP (overvoltage protection relay) have blown two times today.
The OVP is almost brand new.
The tachometer dies and the electronic idle regulation (ELR) fails.
Can this be caused by faults in the electronic systems supplied by the OVP, for example short circuit in the ELR-control unit?

Or is the most probable culprit the alternator?

Thanks in advance for any advice

check for short circuits

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Any blink codes present?

Original harness been replaced yet?

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Hmm, have not checked....

Funny you should ask...
I just had a look see under the intake manifold and the cable harness is in really bad shape.
The insulation on the wires connected to the ELR-actuator is completely disintegrated.
It will have to be replaced as soon as possible.
Checked EPC and where I live (Norway) the harness will cost 1.150 USD

>>where I live (Norway) the harness will cost 1.150 USD

I fitted one about this time last year, which cost me just less than £300 in the UK - if it's the same part number, and you know someone who is coming across...

W124E300TD - Sorry to hear about your problems. Although my wiring harness is currently in good condition, I know that it will only be a matter of time before it goes ka-put.
Almost $1,200 sounds like lots of hard earned cash for a harness...can't you find someone to rewire it for less?
I'm sure I read somewhere, either here or over at Benzworld that one of the members is rewiring harnesses and seems to be doing an excellent job.

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1995 E300 Diesel
2002 GMC Duramax CC LB 4X4