wait light

[rbesaw]

I have a 1986 blazer that has been starting just fine, today I tried to start it and the wait light took forever to go out and the truck still would not start. the glow plugs are about 1 and 1/2 yrs old

 

[Matt65]

Welcome to the forum!

 

[24farragut]

This happned to me with my M1008 two weeks ago. Wait light took a few min to shut off, and truck didnt start, but prior to had always been very quick. Go to the fuse box in the cab, look for the one labeled GP, i think it is 20 or 30a, check it out, could be the culprit. I actually found i didnt have that fuse, put one in and it started right up.

 

[markg]

I have a 1986 blazer that has been starting just fine, today I tried to start it and the wait light took forever to go out and the truck still would not start. the glow plugs are about 1 and 1/2 yrs old

ill bet your glow plug card is bad, turn your key to on, listen for the click of the solinoid under the hood, and see if the voltage gage drops from current draw. if none of those things happen, to start your truck, go under the hood and jump the solinoid for about 5 seconds to energize the plugs, jump in and start your truck. wire yourself up a switch or buy a card off flee-bay thanks, mark

 

[doghead]

His system has been working, why would you suspect a bad control card?

Testing your glow plugs is the first place to start. Then the GP relay if you do not find any bad gp's.

Remove the wire from each glow plug. Measure it with an Ohm meter. 0-3 ohms.

The controller senses voltage, which helps make it decide when the wait light goes out. The voltage drops when you have 8 good glow plugs.

If you PM me your phone number, I can give you a call and talk you through any issue your having. (if you want)

 

[markg]

His system has been working, why would you suspect a bad control card?

i listen for the relay click first and foremost, (and look for current draw) if that happens, your getting juice to the plugs. (normally). in my experience, when the card fails, it doesnt energize the relay. i doubt any of the plugs are bad. i have a stack of bad cards that look good but wont energize the relay. been there- done that.

 

[doghead]

Well, since you cannot "test" the controller card, you must do a component test of all the other components, to eliminate all other possibilities(as per the TM)

 

[markg]

Well, since you cannot "test" the controller card, you must do a component test of all the other components, to eliminate all other possibilities(as per the TM)

if i knew what chip on the card controls power to the relay, i could fix all the cards i have . you can trouble shoot the card to a certain extent, i read it in some tm somewhere. i have seen his problem before, no current draw, no start.