Truck does not glow!

[BlueBreadTruck]

Sometimes when cold, i go to start my truck. When I turn the key ON, i get no wait to start light, I have to turn it off, then back on again and it will glow normally.

any ideas? something is on its way out....

 

[Agnem]

Do you think it is just the light that is not coming on, or do you think the glow plug controller is actually not energizing? Sometimes Lady Moose's WTS lamp doesn't illuminate, although clearly everything else is acting as if it was. I just listen for the relay to open. The WTS usually works fine the rest of the day.

 

[jim x 3]

Do you think it is just the light that is not coming on, or do you think the glow plug controller is actually not energizing? Sometimes Lady Moose's WTS lamp doesn't illuminate, although clearly everything else is acting as if it was. I just listen for the relay to open. The WTS usually works fine the rest of the day.

So what is causing these symptoms? Is the fault in the wiring to WTS lamp (or +12V ) or is the fault in the logic portion of the GPC?

Regards,

 

[Agnem]

As for my specific situation, I've not examined a wiring diagram to see what the cause may be. I suspect a faulty relay somewhere, possibly in the controller itself, but since the actual glow plugs are not affected, it's a really really low priority....

 

[franklin2]

A good way to know if the glowplugs are actually working is to watch your voltmeter. If it swings way down close to the "8" on the gauge, they are working since they are putting a heavy load on the battery.

 

[jim x 3]

As for my specific situation, I've not examined a wiring diagram to see what the cause may be. I suspect a faulty relay somewhere, possibly in the controller itself, but since the actual glow plugs are not affected, it's a really really low priority....

Mel, In my '88 Ignition ON provides +12V to one side of the WTS lamp. The other side is wired to the GPC. The GPC pulls the WTS lead low to light the lamp. So if the lamp is out with GPC working (and the lamp isn't burned out, since outage is intermittent), then there is likely a bad connection in the WTS wire from lamp to GPC. Probably at the connector at the GPC. I'm guessing.

Regards,