Glow Plug Controller faulty?

[Big Blue 84]

Hello, I have a 1984 6.2L K5 Blazer that will not start. I believe the glow plugs and relay are good (changed 5 months ago), however the glow plug light and relay do not come on. The week before it would not start, I noticed the glow plug light would intermittently come on after the engine was warm.

Can anyone help?

 

[diesel4me]

stock setup??

Are your glowplugs still hooked up factory,or have you added a manual overide button to activate them??.

If its still stock,you can manually overide the controller by grounding the blue wire on the glow plug relay while the key is on--you'll hear the relay click as you ground that blue wire(you dont have to dissconnect it,just touch a grounded wire to it)..leave it grounded for a maximum of 10 seconds,and crank it over--it should start if the glowplug relay and its wiring is intact and getting 12V,and the glowplugs work...

I bypassed the controller on my 82 K20 with a 6.2 by installing a momentary pushbutton switch to ground that blue wire at the glowplug relay,and I just unplugged and taped over the plug that goes onto the controller that screws into the intake..and I used AC G60 glowplugs,which are supposedly less likely to mushroom like the OEM ones,and are better suited for "manual" operation..I use the seatbelt buzzer as a "timer"--I simply hold the button on as long as the buzzer is(about 6-10 seconds),and it starts right up..

Its started every time for me,even below zero without the block heater plugged in!..and I could only get 7 glowplugs OUT of my motor--one dead soldier refused to come out(probably swelled up)--and I havend dared to force it out--if it breaks I'll be screwed!- My injector lines wont survive being removed to get the injector out to remove the broken tip---I'm not going to mess with it!..

 

[Big Blue 84]

Thanks Diesel4me. I will give it a try. I am assuming it is stock since I am not aware of any modifications made to it.

 

[Brocky]

ya, I had to do the same thing with my diesel mercury topaz. The controller gave out and I can't get one around here. On my car I ran all new wires to switches inside for the glow plugs. I didn't hook up the relays the first time and burnt up my plugs, so the next time around I ran them off the relays and it's been running fine for 3 years now.

 

[Big Blue 84]

Bypass Controller worked

Thanks for all the feedback. As recommended, I connected a wire from chassis ground to the relay terminal (with the blue wire connected to it) and the Blazer started. The glow plug light came on also.

Two questions:
1) How do I wire to a switch?

2) How will I know if the glow plugs need to come on to start the vehicle? By turning on the relay manually, will I burn up the GP's faster?

Thanks for all feedback!

 

[diesel4me]

its simple...

All you need is a momentary push button switch--one wire from it to the blue wire on the glowplug relay.and the other wire to a good ground..(no need to disconnect the blue wire from the relay--just "tap" into it..)

Most 6.2's wont start without activating the glowplugs,even on a warm summer day--you wont have to energize them for long in warm weather,about 5 seconds should be long enough--add more time as the temparature drops..I'd use the G60 AC glowplugs on a manual override ,the stock ones can swell up and refuse to come out if you leave them on for too long....

 

[Big Blue 84]

Routing of wires to switch

10-4 on the glow plugs coming on, even on summer days, which basically answers my prior questions.

How do I route wires to the interior of the vehicle?

Thanks for the advice.

 

[diesel4me]

I just slid the wire thru the firewall where some other factory wires came thru--you could drill a hole and put a grommet in the firewall,but I think thats not really nessasary...there should be at least a few places you can sneak another wire thru..sometimes there are rubber plugs in the firewall you can snip the end off and put the wire thru...

 

[Big Blue 84]

Thanks for all the help!

I was unsure of how to do it, and will now give it a try.

Thanks a bunch!