Glow plugs only come on if engine is warm

[visotzky]

Like it says. When i try to start in the morning, no clicks. After I get it running and drive a while and turn the engine off. Start the car again after a while( up to three hours later) and two clicks , just like it should. Could it be the temp sensor?
I recently replaced the ecu,and it worked fine for a month.
Cheers
Val

[loki]

probably the temp sensor

[Jester]

I got into the van this afternoon and also got no clicks.
Where is the temperature sensor?
Could it be something else? Is there a fuse for glow plugs?
Any experiences fixing this would be most welcome...Winter is coming.

[Green1]

I got into the van this afternoon and also got no clicks.
Where is the temperature sensor?

temp sensor is on the top of the engine near the front, has 2 wires on it, one goes to the glow controller, the other goes to the dash gauge (it's actually 2 sensors in one unit)

Could it be something else?

always! (glow controller, relays, wiring....)

Is there a fuse for glow plugs?

yes. right at the battery there is a fuse (80A I think) for the glow plugs.

[Jester]

Thank you Grren1
I'll start troubleshooting.

Something I was thinking about though, is that before this happened my glow plugs ALWAYS cycled when I turn the ignition on.
No matter what the temperature, how long I driven, how hot the engine.
So I'm thinkin' I have a faulty temperature sensor no matter what other problems may be present.

....mann this is NOT the time of year for glow plug problems...

[Spearo]

Thank you Grren1


....mann this is NOT the time of year for glow plug problems...

Murphy's Law and all that.
Same as finding out your windshield wipers are broken. When else but when it's raining?
Cheers,
Erik

[jessef]

Same as finding out your windshield wipers are broken. When else but when it's raining?
Cheers,
Erik

funny you say that.

The bladed on my L400 are junk and I went to replace them only to find out they are not common mounts. Canadian tire, lordco didn't have replacements. The guys said they never saw a wiper mount like that.

I had to take the off/put them on a few times in the pissing rain.

Still on the hunt for one's.

[Green1]

Something I was thinking about though, is that before this happened my glow plugs ALWAYS cycled when I turn the ignition on.
No matter what the temperature, how long I driven, how hot the engine.

On the L300 the glow plugs will ALWAYS cycle on, regardless of temperature/run time/etc. the only difference will be how long they stay on for, when the engine is up to temperature they usually come on for less than a second, whereas when it's really cold they can be on for 8-10 seconds (-20c sitting overnight)
On the L400, I'm not sure, but it seems that they don't bother at all if the engine is still warm... but don't quote me on it...

[Jester]

can someone direct me to the glow plug relay and controller?
I looked at the diagram on wiki, but it's no help to me..

Also, what's the troubleshooting for the temperature sensor? is it continuity=no good or reverse or something else?

[Green1]

can someone direct me to the glow plug relay and controller?
I looked at the diagram on wiki, but it's no help to me..

Also, what's the troubleshooting for the temperature sensor? is it continuity=no good or reverse or something else?

Controller is inside the driver's "B" pillar, relays are in the air filter compartment (under the driver's seat) behind the plastic air duct that runs along the aft side of the compartment. (the bolts to get the controller out is also in this compartment, you'll also want to remove the seatbelt retractor)

as for the temperature sensor, resistance varies with temperature, if it tests open it's bad. (resistance measured from the lead to the engine block, not to the other lead as they are independent)

[Jester]

Thank you, I shall dig into my grumpy van further, and post my findings.

[Jester]

So as far as I can tell the wiring seems intact, the controll unit has no blown capacitors or anything like that..
If one of the glow plugs goes, that wouldn't cause the whole system to loose continuity, would it?