Glow plug voltage 1984 300d
 

Hey Folks
What should the voltage be at the glow plugs during the glow interval. I get 9.5 volts on all plugs + the fuse. When the relay trips I get 12V. Is this normal?


Thanks

Glow Voltage at Plugs
 

'Think about all the power those Glow plugs suck up?
9.5 Volts ain't the greatest...BUT it'll turn the tips Cherry Red and start the engine.

Please see my unsolicited short novel, on your other post, about the best way
to get this baby back up on the Parking Lot known as I-575.

Thanks for the post, I come from a town called Hope.

Sounds about right. A little higher voltage might be better but to get it you might have to increase wiring size.

Cleaning all the connections in the circuit including the block ground and body ground can give you a little more. Make sure to treat all those connections if you where to clean them. Actually a good preventative move on an older car unless you live in a place like arizona perhaps. Even clean the battery connections well and treat them.

I try to always remember that I am not dealing with a younger car anytime I work on a 123. There are conditions that deteriorate with time that are not considered by many. If you want reliability in an older car it takes some effort to keep it. Basically a lot of detail items not really costly to perform need checked.

A good example is the ignition lock getting shakey. Change it before it costs you a lot more to deal with. It is not going to get better. It can even strand you somewhere. Electrical connections are in the same catagory. Doing these small chores helps reduce the frequency of problems.