Glow plug light not going on.

[Nessy]

My car hasn't been starting well for about 1 month than about 1 week a go the glow plug light doesn't turn on anymore when i go to turn on my car it just chugs. I thought this was because my glow plugs arnt working so i changed my glow plugs but the light doesnt go on. what could this be im new to diesels

[Vincent Waldon]

Unfortunately the light on the dash is not actually connected to the glow plugs... it's connected to the glow plug relay (big tall sucker on the fuse panel).

If the light was working but stopped *and* the car is hard to start it's a reasonable guess that the glow plug relay has gone south... swapping in a new one is probably the easiest test.

If you have a multimeter or test light you can confirm power at the glow plug buss and work your way back.

[Vincent Waldon]

im new to diesels

BTW... welcome to the forum Nessy!!

You're gonna have fun... I'd highly recommend you give the FAQ a once-over to get you started, and we also recommend you put your location in your profile in the event you have a question or comment that has a geography component to it.

[Nessy]

Okay thank you so much i put my location to lol

[Vincent Waldon]

Okay thank you so much i put my location to lol

Merci!!

[jettabrendan]

It could also be the glow plug fuse by the firewall no? I'm having a similar issue except the light is staying on longer than it should. I would check the fuse first.

[Vincent Waldon]

Nah, sadly the light has a mind of its own... not related to the fuse.  The fuse is downstream of the glowplug relay and protects the heavy-duty wiring that provides 60 amps to the glow plug buss.

In your case, if the light is staying on too long the glowplug relay thinks it's cold out.  This can be caused by a defective temp sensor, broken/damaged wiring to the sensor, or a defective glow plug relay.

I usually start by checking the wiring at the sensor itself... it can break and/or disconnect itself, particularly given the vibrations of the average diesel.  After that, the sensor is only a few bucks...  :wink:

[jettabrendan]

Well if you need a gp relay I have one with your name on it. Oh and which sensor is it that is related to the gp. I replaced both on the collar on the front of the head. Still stays on.