Glow plug relay mod

[livn2play]

I am trying a resistor in to lengthen my glow plug cycle times. I have a 10ohm resitor and thought I have done everything the way it explains it in the manual. When I put the resistor I can't get my glow plugs to cycle, if I put a jumper wire inbetween the resistor they cycle, at the regular cycle time. What could I be doing wrong to not get a cycle when I put the resistor in? Could the controller be getting weak? I have an 1985 truck.
Any help would be greatly appreciated, I didn't think that such a simple mod. could be this frustrating.............

[More Power]

Originally posted by livn2play:
I am trying a resistor in to lengthen my glow plug cycle times. I have a 10ohm resitor and thought I have done everything the way it explains it in the manual. When I put the resistor I can't get my glow plugs to cycle, if I put a jumper wire inbetween the resistor they cycle, at the regular cycle time. What could I be doing wrong to not get a cycle when I put the resistor in? Could the controller be getting weak? I have an 1985 truck.
Any help would be greatly appreciated, I didn't think that such a simple mod. could be this frustrating............. Are you sure the resistor is 10 ohms? Is it a 2 watt or higher rated.

Jim

[snoman87]

Here is how mine looked ... installed the 10ohm 2watt and it works no problems. You must have something off.

My wire harness mod web page (http://www3.telus.net/gmc62td/engine_harness.htm)

[joed]

I'm thinking about doing this mod. as well to my recently acquired 82 6.2 (the orig. 82 controller died). In looking at the 85-93 glow system schematic, as an alternative, could you install a switch to send 12V to pin C after the controller's initial glow cycle to extend the time? This way you would have some manual control when longer times were needed?

Please forgive my electrical ignorance.

Thanks. Joe.

[livn2play]

The resistor is a 10ohm but I think the watts are higher, than a 2 watt. I am taking that this will make a difference? I guess my assumption was that the higher the watts the more load or current it could handle and the ohms creates more or less resistance. Let me know how the watt will affect the function of this mod.

[More Power]

The wattage spec is an indication of how much current flow the resistor can handle without damage. That wattage was determined during our tests when first developing the extended glow modification for the 1985-93 glow system.

When the glow system doesn't work with the resistor, but does without, I suspect the resistor value may be more than 10 ohms. A value of 5-10 seems to work fine.

Jim

[CleviteKid]

If you want to be exotic, do what I did, insert a NTC (negative temperature coefficient) thermistor in place of the resistor. It gets higher in resistance as the air gets colder. Glows longer cold than hot. Works like a charm.

Dr. Lee :cool:

[Portland Suburban]

Personally, I prefer manual. smile.gif

[BobND]

Manual is JUST FINE, until someone else has to drive the truck!

[NH2112]

I don't see why people say "manual is just fine until someone else has to drive the truck." Come on now - if the person you're letting drive the truck can't comprehend simple instructions like "turn key to ON. Push glow plug switch for 15 seconds. Release glow plug switch and start vehicle" then maybe he or she doesn't have quite enough intelligence to drive a truck in the first place.

[More Power]

It's hard to predict who might need to drive the truck in an emergency - or in your absence.

www.peninsularengine.com (http://www.peninsularengine.com) sells a simple glow timer that glows the plugs for a user defined length of time - and that is activated when the ignition key is first rotated to the run position.

I know one guy who drove his 6.2 truck for more than 200,000 miles over many years, and never had an operational glow system. He used ether for every cold start. Not my idea of convenience, but...

Jim

[NH2112]

I know that just about anyone could need to use the truck, but who else are they going to get the keys from, if not you? If the significant other has a set of keys, he/she most likely knows how to start the truck and can give instructions. If it's a REAL emergency nobody's going to come looking for the keys, they'll either push or tow it out of the way.

My point is that use of a manual glow controller is hardly rocket science that can't be explained or demonstrated in a few seconds while handing over the keys, and that I don't think anyone could think up a reasonable, likely, scenario that wouldn't allow time to explain the use of the manual switch. Hell, the tire monkeys at Sears don't have any problems getting my truck started and they're getting the instructions in scribbled form from a 3rd party (the service writer.)

[BobND]

I run 60G's, and have done the extended glow time mod (to about 15 seconds, COLD), on a couple 6.2's I have. (Also moved the controller to the fender, and eliminated the "warm glow plug inhibit switch".)

They start better than EVER, warm or cold. I've had no trouble over a couple of years, and ANYBODY can jump in and start them, with NO instructions, scribbled or otherwise.