Glow Plug Relay Issue

heliodriver · Feb 12, 2023

New to me dk40se.

When I got it, it did not start worth bean. Previous owner had wired in a manual glow plug switch to activate the glow plug relay.

Found 3 burned out glow plugs. Replaced them. Starts good now.

What I'm finding is that I get less than 1 volt to the signal wire at the glow plug solenoid when the glow plug light is on.

After the glow plug light goes out, I get a full 12 volts to the solenoid signal wire. This will keep the glow plugs on after then engine has started and the glow plug light goes out.

Any suggestions and does anyone have a wiring schematic for the glow plug circuit?

Venturabass · Feb 15, 2023

You’re referring to the singal wire to the glow plug relay, right?

The only thing I can think is that it’s wired such that the machine is supposed to deenergize the relay in order to complete the circuit. Normally I’d think that it’d be set up to energize the relay to complete the circuit. It’s sounds backwards, but without a wiring diagram hard to know.

Have you tested the plugs or harness to determine if they correctly get power when activated, and that they shut off after being activated?

There is a listing of shop manuals you can download in the owners section. However a simple call to your closest dealers service dept and they may know the answer.