Hi All,
I am at a loss here. I have a 99 ML320 that began to shut off randomnly without warning. The engine would shutoff while driving and I would lose most electrical components. When I would try to restart it would not crank, click or anything and then suddenly all dash lights would come on and it will start as though nothing happened. Also when it shuts off I have headlights,horn, radio, seats, lcd dash (odometer, temp, clock). No locks, mirrors, windows, warning lights, climate control, flashers, signals...Also no check engine light after restart. After the latest shutdown it has not reset itself and this time it seems for good. I have checked all the obvious (batt., cables, relays, fuses, second key,) Any suggestions would be appreciated.

sounds like a voltage supply issue.

there is a relay in the main fuse & relay box marked circuit 15.

you can try swapping that relay with another with the same part number.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks for the reply MBDOC. Unfortunately it wasnt the circuit 15 relay. I swapped all the same relays and nothing. Is it possible to be the ignition switch/lock? The conditions almost mimic the position 1 of the switch when going from run position to 1. Is there a test with a multi meter I can do to eliminate the ignition switch? I can unplug the back of the switch to get to the male and female connectors.

Is the circuit 15 relay getting the "turn-on" signal from the ignition switch?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I pulled the fusebox from its housing and pushed on connectors, moved wires and knocked on the thin plastic box that comes down the left side of the fusebox assy. As I was doing this the power came back on! The bad news is I dont know what caused the problem, in case it happens again. but at least I narrowed it down. Do you know what the black plastic housing on the lower left side of the fuse box is? Thanks for your help.

Hi,

Im having the same problem with my ml320 1998 have you found a solution to this strange problem ?

Thanks

Best Regards

Any idea what this could be , I am having the same issue.

Air filter?? That is what happened to my car.