Help! 123 won't start - electrical prob.

[DerBenz]

Car is a '84 300D (617 eng.) Mileage is about 228,000mi.

Wife went to start the car this morn. and it wouldn't even turn over.

The symptoms when ignition is turned-on:
1. Instrument cluster lights noticeably dim (about half normal)
2. Tachometer needle pegs all the way to the end
3. Buzzing/squeeling sound coming from under hood

I'm gonna diagnose soon as I'm off work. Searching archives, I'm thinking voltage reg. or alternator.

Any other ideas? Anyone had this problem/symptoms? Thanks

[stevebfl]

The immediate problem sounds like a lack of battery voltage getting to the starter which can be caused by high resistance in any of the connections along with the obvious possibility of a bad battery. If the battery is low check also the alternator. The alternator DOES NOT need to be working for the car to start, but it is required to keep the battery charged.

[IMUL]

Lack Of Voltage. I had the EXACT symptoms in our SD recently. Turns out that the negative battery terminal was corroded. I cleaned the terminals and haven't had the problem since.

[DerBenz]

Thanks for the help, Stevebfl and IMUL!

Problem seems to be the battery. Voltage across terms. was 7.55. Alt + volt. reg. is only a couple years old w/about 55,000 mi. on it.

I swapped another battery in there temporarily and I've been watching the voltage as I've been driving the car and no loss - so it appears alt. is ok.

The battery was 47 mos. old. Seems about right to go now given that 45-50 mos. has been my average w/batteries.

Diesel engines require a really high ampherage output to crank, so you won't get much action from under the hood if the battery is dead or near dead.

Also unlikely that a "jump" will work, except from another diesel. Even from a tow truck's cables, which are set to start gasoline engines and won't generate enuf cranking power for you.

I'd also suggest you don't give a gas powered vehicle a jump from your diesel. Amps could fry some electronics.