Glow controller upgrade problems.

[Jgreemo]

After a long delay, thanks to work and good surf, I finally got around to installing the 85-93 g.p. controller. Install went well and all my connections look and meter good. But, no glow. The relay will not close and despite rechecking all the connections, no joy.

Thanks to a dead soldering iron, I could not solder all the connections, but they all looked good on the meter.

The setup so far:
-I have one lead to a 12 v ignition on source.

-One to a ground.

-One to the yellow lead off the old controller. To this lead I added a 9 ohm resistor, which was soldered.

-One to the starter solenoid (purple), which is 12 v at start only.

Wired them all in according to Dr. Lee's article and still the relay doesn't close.

A few questions to those of you who performed this upgrade: Does the ground have to be to the engine, or will the chassis work?
On the old relay, there was a small green wire tied into the 12 volt "ignition on" lead by what looks like a small resistor. I don't have a wiring diagram for this, so any ideas as to it's purpose?
Is there any way to test this controller? I purchased it new from GM, but it would be nice if just installing a replacement would solve the problem.

Thanks for the help. The old controller (which was only a year and a half old, was on the fritz so it as time to change it. Now, I have no glow at all, so hardly an improvement.

Jon

Well, found the trouble shooting article in the online guide. Will check the ground and my ignition switch.
Thanks!

[Jgreemo]

Can someone who has installed the upgraded controller confirm this wiring arrangement?

On the harness:

A- empty
B- switched 12 volt
C- feedback from old controller (yellow wire)
D- 12 volt on run (purple wire)
E- ground (now to both chassis and block)

I rechecked all connections, wired up the ground to both chassis and block, and picked up another controller today, checked it, and still no luck. The controller is mounted and has power but no relay action.

Any ideas?

Thanks
Jon

[john8662]

I've never done the upgrade, although it's on my list too.

My question is in regard to your upgrade, you already have an 85 model, which already had the integrated glow/relay controller. So did you have the cigar-style controller or the electronic controller?

According to the diagram under the troubleshooting section on the main site I seem to think that your problem is with pin C

Pin C is the glow inhibit switch, so if it's not used you have to cross it to the hot on the diagram.

So, looks like you need to cross the pin C to the main lug on the glow circuit that supplies power to the glow plugs. Otherwise you'll never get anything.

You'll want to abandon the yellow wire if you had the cigar style controller.

Make sure you test the other two wires, one that's only engaged when the starter is cranking, and another that gets power when the ignition switch is on run (constant power).

[Jgreemo]

Thanks John, I tested out the two hot leads today. One is the power on run, the other, power on start. Both are ok.

It looks like you are on to something with the inhibit switch. I do have the old cigar style controller and I jumpered the yellow wire, plus a resistor over to the new controller at pin C. Unfortunately, my 2000 reprint, which had the article featuring the upgrade, went missing.

If I read you correctly, I should cross pin C into the hot lead on the relay. I did see the troubleshooting section, but one question, does pin C pick up gp feedback before or after the plugs? Without the 2000 article, I was thinking the yellow wire was the feedback after the glow plugs, with the gps acting like resistors.

Anyways, I'll set it up like you suggest tomorrow. I do appreciate the help.
Jon

[john8662]

I think that the yellow wire you're referring to is the alternator feedback wire, this was to give the glow controller signal by means of alternator output that the engine is running, which would initiate after glow. The new electronic glow controller that you're converting to no longer needs this wire. It only needs (according to the diagram I'm looking at online) here (http://www.thedieselpage.com/members/guide13.htm) an:

-ignition run hot wire, Pin D
-a starter sense wire (keep controller from coming on while you're cranking), Pin B
-a large amperage (10 ga) supply wire,
-connection to the glow plugs.
-Ground connection, Pin E

To answer the question of before or after the plugs, I'm not really sure. But if you don't have the inhibit switch (like you're now going to bypass) you'll probably get glow time every time you turn the key, which I think is a good thing.

You'll take Pin C connection and make a jumper that connects to the large lug that has all the glow plug wires going to it, not on the unswitched hot side.

[mhagie]

Hey guys go to the members area,scroll down to the reference section click on the online 6.2/6.5 troubleshooting resource.
Glow plug controller stuff is there.
Merle

[john8662]

jgreemo,

Hows it coming? Is the little light in the cab glowing before a crank now?

[Jgreemo]

Thanks for checking in John. Everything is working perfectly, after rewiring the C pin. I have a bit over 10 seconds of glow (with light), using Kennedy quick heats. I imagine in the winter, that time will be longer.

I also found that mounting the new controller was pretty straight forward. Simply notched the two mounting tabs on the new controller with a dremel, slipped in the rubber isolators from the old relay and drilled a new hole in the fender.

Thanks for your help. Without the proper wiring diagram, I was having a bit of confusion.

Best regards,
Jon