Simple glowplug question, 7.3L

[timmi]

What exactly is happening while the "Wait To Start" light is ON? My battery gauge doesn't show much activity while this WTS light is on. The GP controller starts its cycling a few moments after the WTS light turns off, and this cycling is noticeably shown on the battery gauge, which I assume is normal..?

Are the glowplugs being warmed during the WTS period or is it afterwards? Or both?


Thanks,
Tim

 

[Dsl_Dog_Treat]

Tim,

I'm guessing that you are watching the factory dash voltmeter?

I don't see much difference on mine, hence an aftermarket digital voltmeter on my radio plus a mechanical one, they'll show some number crunching.

The first time you cycle the GP is on constant and usually drops to around 10.5 volts when the relay is activated and should be on for around 12 seconds, little longer in the colder temps.

A quick easy way also is to have the dome light on then hit the key to cycle the relay. That will tell ya also as the relay draws a huge amount of power to light up the GP's.

As far as cycling of the GP's the answer is both periods do provide current to the GP's.

WTS light acitvated = relay constant on.
WTS light deactivated = relay will cycle on/off for about 30 seconds thereafter.

Sounds like a normal system to me.

 

[timmi]

Thank you

That all makes sense.
Thank you sir.

 

[93_E_350]

Not sure what year you have but check my web site and go to Diesel Informationfor then Glow Plug and Controller Analysis 1993 , look at the whole document it gives you a temperature / time range that the relay should be running also – you might find it interesting…