300SD Starting Issues - Page 2 - PeachParts Mercedes-Benz Forum

#16 01-03-2008, 11:37 AM

Quote:

Originally Posted by LUVMBDiesels

I tend to agree with the bad starter crowd. However, you can hot wire the car from the juction box on the passenger side. If it starts consistently by hot wiring it, then you probably need a new neutral safety switch or ignition key starter switch.

I agree too, these intermittent failures can be a PITA. My old POS jeep did that for months until the failure finally got frequent enough to diagnose, turned out to be a bad NSS.

94mgm · #17 01-03-2008, 12:01 PM

If you hear a click:
when you turn the key, if the lights go dim, its the starter. If they dont, its the solenoid.

If you don't hear anything:
Check your connections

Brian Carlton · #18 01-03-2008, 12:24 PM

Quote:

Originally Posted by 94mgm

If you don't hear anything:
Check your connections

.........or it's the NSS.

LUVMBDiesels · #19 01-03-2008, 01:25 PM

Quote:

Originally Posted by 94mgm

If you hear a click:
when you turn the key, if the lights go dim, its the starter. If they dont, its the solenoid.

If you don't hear anything:
Check your connections

The lights will dim when the glow plugs are heating as well. If they do not get brighter in 45 seconds then it could be the battery or a stuck on GP relay.

Best way to test would be to make sure the car in in park, then jump the two outer screws in the junction box If the starter spins, it is OK. If not then it is probably the starter assuming the battery is charged and the wire to the motor from the juction block is not loose.
I would also check the ground strap from the engine to the chassis.
If it spins then the issue could be in order of probablility:

1) NSS
2) Key switch
3) Wiring from the key switch to the solenoid...

Hope these help