24v to glow plugs, 60G's still ok?

[GFB]

Card is toast, but the push button system is up and running. Getting 24v to plugs. Do I need to buy a new resistor bank or are the 60G's ok with that much voltage?

 

[DonK]

Replaced mine with the same 60G's with the existing resistor bank. Now have 8VDC at the load side of the GP relay when energized. Started fine for the first couple weeks. Now I 'm starting to have issues and I'm not sure what the problem is. From what I've read, the 60's should be ok as long as there are no other issues.

 

[GFB]

Or if it's cheaper (haven't priced a new resistor), maybe put in HMMWV glow plugs?

 

[mistaken1]

With a functioning resistor and stock glow plug relay wiring you will measure 24V at the relay until it is energized. The resistor will not develop a voltage drop without current flow. You have to measure the voltage at the relay when it is energized to see the voltage impressed on your glow plugs.

Another option is to place your meter leads on either side of the resistor when current is flowing to see the voltage drop across the resistor.

 

[GFB]

With a functioning resistor and stock glow plug relay wiring you will measure 24V at the relay until it is energized. The resistor will not develop a voltage drop without current flow. You have to measure the voltage at the relay when it is energized to see the voltage impressed on your glow plugs.

Another option is to place your meter leads on either side of the resistor when current is flowing to see the voltage drop across the resistor.

I'm not sure what you're saying. I'm measuring voltage at the glow plugs. The only time they will receive voltage is when the relay is energized. If I'm receiving 24 volts at the plug, then I'm getting no or very little drop across the resistor, right?

Are the 60G's ok with that much voltage?

 

[DonK]

Correct...that means the GP's are open. Measure the resistance, they should read about 1.2 ohms.

 

[MakersTeleMark]

Those 60's will fry at 24v, that is why the resistor is there.

 

[DonK]

Others (oldtimers) have suggested using the 60's which I installed in my 1009. You asked about the voltage, if you don't have a source to ground, you won't have a voltage drop. That's why I said they could be open. Measure what you have just to be sure. Remember you have 8 GP's attached to the 24 volt source, the voltage drop should be below 12vdc if all are good. I'm at 8vdc with good plugs.

 

[mistaken1]

I'm not sure what you're saying. I'm measuring voltage at the glow plugs. The only time they will receive voltage is when the relay is energized. If I'm receiving 24 volts at the plug, then I'm getting no or very little drop across the resistor, right?

Are the 60G's ok with that much voltage?

Correct. No voltage drop at the glow plugs means there is no current flow.

As DonK pointed out if there is no current flow it is most likely because all of your glow plugs are open (ruined).

Even if the resistor were shorted, good glow plugs would drop the voltage (at least for a while). A functioning glow plug controller card would sense the high voltage and short cycle the glow plugs in an attempt to prevent them from being damaged due to over-voltage.

http://www.steelsoldiers.com/cucv/64968-winter-starting.html#post773056

 

[GFB]

It finally sunk in late last night and I understand now. I replaced them all again this morning, but since the card is fried and I have installed a bypass switch, I switched them to a 12v feed. I know this isn't the best option, but for what little this truck will be used (beater/hunt/fish/fun) I think this will work just fine. Thanks guys!

 

[mistaken1]

So you got your truck starting again?

 

[GFB]

Yes. Those plugs burnt up after ONE start LOL. I knew the extra voltage was going to be hard on them and was working on troubleshooting it, but I wanted to also drive the truck a few times to figure out what else might be wrong with it while I have the time to work on it. I couldn't believe it happened that quickly. That was a mistake, and the ones that hit your wallet seem to help you learn faster. I still have one of the old 13G's that I cannot get out. I'm going to get a 30mm socket and a hemostat before I try prying on that one even harder. But, seven 60G's running on a 12v feed starts the truck great for now. Thanks again guys for all the help.