No glow plug power

[Glock Cop]

Please help. I have a 1985 6.2 pickup. A few weeks ago the glow plug light in the dash stopped working and I could no longer hear the relay doing its usual clicks and cycles. It will still crank pump fuel and everything else just no power it seems to the glow plugs/controller. I have replaced the glow plug controller,the temprature inhibit switch and checked for broken wires or burnt fusible links and have found nothing. Any ideas from the experts? Am I overlooking something simple? I love this truck and want to drive it again and this is driving me (and wife) crazy. Thanks

[Robyn]

Be sure you have ignition voltage to the glow plug relay.

I will pull up my schematic tonight and post exactly what wires should have what to them.
Be sure your heavy gauge cable on one side of the realy has full battery voltage.

Be sure there is not a stupid little fuse in the panel that is toast. :eek:

Later

Robyn

[Robyn]

Ok

Looking at the glow controler from the front of the rig.
You have the two heavy lugs in the front and the gang plug in the back.
The far side pin (drivers side) is the ground and the wire to it in the plug is BLACK be sure it is grounded This is terminal "E"

Them next one over is the PINK wire and it should be hot with the key on
Terminal "D"

Then comes terminal "C" YELLOW this goes through the inhibit switch to the glow plug wires in the harness on the engine. Make sure this wire has continuity through to the glow plugs.

The next is terminal "B" and this one is a purple wire and is hot during cranking only.
The "A" terminal is not used.

Check out the wiring to make sure things are the way they should be and that you have voltage where you need it.
A bad ground will kill this thing totally as will no feed from the ignition switch.

The inhibit switch must be closed so you get a complete circuit for the relay to work. If need be you can jumper the plug and forget the inhibit switch as it is not needed. (REAL PITA)

Had an inhibit switch fail to close in Spokane washington in the winter and had no tools with me. Managed to bum a paper clip off the Motel manager and jumpered it and wrapped the sucker with duct tape to get home.
Seems that that paper clip and duct tape went with the Burb when it sold.:rolleyes:

Hope this helps

Robyn

[Robyn]

Oh BTW

Welcome to the forum glad to have you. :D :D

I assume by your handle you are a cop.

Yes Glocks are a fave with me. I own a gun shop and cater to local law enforcement folks as well as the public.

Robyn

[Glock Cop]

Thanks for the info. I am on my out to the garage to take another look.

Yes, I am a state trooper and not only carry a Glock on duty, but shoot Glocks in IPSC. The wife (who also shoots IPSC with a Glock) works part time for an indoor gun range/shop here in Oklahoma. Small world, huh? Do you have a web site for your store? Now she is planning a trip to Oregon!

She will be happy when the truck is fixed because I am "using all her gun and ammo money" to buy parts.

[HammerWerf]

Could be the relay has died. I've had 2 quit on me. A real quick & dirty test that will get you going is to use a jumper wire from the near battery HOT ( + ) terminal to the back side othe relay ( large lug with the 2 heavy wires attached. This is a short cut method of the starter circuit. Use a heavy guage wire ( 12 AWG. minimum) THis will produce some sparks, but will apply voltage directly to the glow Plugs and indicator light. The light is wired in a parallel circuit so that if you apply voltage, the light should turn on.

Now depending on which glow plugs you have installed, limit your application of power to about 4-5 seconds ( AC 9 or 11G) or don't worry about it (AC-60G). If you don't know, assume 9 or 11G and keep the time short.

Like I said, a quick test to test that checks the fusible links (buried in the wire loom by the back cylinders.

Welcome to the forums.

HammerWerf

[Glock Cop]

Okay first I want to thank all for your help. It appears Im getting no power to the glow plug relay. I test the pink wire with key on and my test light lights up. I touch it to the hot side (heavy red wire) of the relay and get nothing. Could the ignition switch (on top of the steering column) be causing this? Im next going to try hammers method of jumping across and see if I can eliminate something else and a t least give me something to go on. Again A BIG THANKS and Ill post results a little later.:confused:

[Robyn]

Does the relay click when the key is turned on?
If yes then there should be power on both heavy lugs of the relay.

If the relay does not click then check the gound wire (Black one on the plug)
Also make sure the inhibit switch has continuity through it too.

The link to our web site is www.bigborecanyon.com (http://www.bigborecanyon.com)

Let us know

Robyn

[Glock Cop]

Now you have done it!! My wife was looking at getting a Rock River AR for her birthday after the first of the year. Now she is booking flights to Oregon as I type!! LOL Cool SUV, BTW. :eek:

[Glock Cop]

I tried the jumper wire from battery to controller where the two black wires are and I got a click and dash light lit. SO what do I do now? What did this show when I got those results? Also Robyn to answer your question there seems to be a click at the controller when you put the key to ON but no glow plug light. Could this be the inhibit switch(which I just replaced):mad: And if so could you explain the paper clip trick?:confused: I would really appreciate it. So close yet so far.

[Robyn]

The inhibit switch is the one on the RH rear of the engine "ON top"
The one down on the side of the head at the rear by the exhaust is the Cold advance switch.
The one on top can be defeated simply with a jumoper wire with two spades connected to it and plugged into the connector.

If you replaced the one on the side you have the wrong switch.

The paper clip trick is the down and out stuck in the parking lot last ditch effort thing.

If your relay is clicking when you turn on the key then Im suspicious of the inhibit switch or a connection.

If you have 12V on the pink wire and the black wire on the far right of the connector is grounded good the relay should work and things should glow.
This is unless there is an issue in the inhibit circuit.

[PVSLS400]

hey guys been searching alot and i have the same exact problem on my 94 3500 hd 6.5 td where is the relay located at?

thanks
Josh