Glow Plug Voltage

[TGP (IL)]

A'm I to understand the GP sytem should be 12V.
I'm reading 25.5 at the relay,engine off.
Needless to say all the GP are toast.
Was there a 24V set up.
I haven't dug into yet but the wires all good and original,except for a new relay.
Should I pull the cover of the firewall mounted resistor's and see if it's been tampered with?(wired wrong)
Thanks for any help.
TGP

 

[nk14zp]

http://www.steelsoldiers.com/cucv/62990-yet-another-glow-plug-question.html

 

[nk14zp]

http://www.steelsoldiers.com/cucv/45694-glow-plug-voltage.html

 

[TGP (IL)]

http://www.steelsoldiers.com/cucv/62990-yet-another-glow-plug-question.html

Thanks
TGP

 

[doghead]

What kind of reply is that? Someone posted 2 links with information that they thought would help you and you reply with that?

Post like that again, and you'll have some time off.

 

[TGP (IL)]

Ok I'm Sorry for that and I hope he accepts my apology as I did not see the links.
They don't show up well here on this monitor.
I figured he was picking on a newbe.
That's what I get For Thinking!
So now I have more than one major problem.
Thanks,
I have read those threads.
TGP

 

[Marlboro]

HaHa i see were you could take that as a wise remark if you didn't know it was a link

I like the dually!

 

[doghead]

So you missed the fact that they were links!

Your reply is much more understandable knowing you missed the links.

Do you have a better understanding of thet GP system now? Or need more info?

 

[Warthog]

We all learn the hard way don't we....LOL


***** WARNING - LINKS INCLUDED *******

Welcome to the site.


Make sure you visit the Cucv Wiki - Steel Soldiers::Military Vehicles Supersite (CUCV Wiki) that is at the top of the page on the CUCV Forum. All of the CUCV Technical Manuals are listed and many other helpful bits of information.

Make sure you download the repair manuals. You can get then for free. A couple of our members have posted them on their websites.

Also the wiring diagrams are in the appendix of the -20 and -34 manuals.

JATONKAM35s HOME ON THE WEB

Also checkout the http://www.steelsoldiers.com/cucv/20600-faq-thread-cucvs.html stickey. It is where we try to post helpful tips and tricks.
Almost every question you will have has been asked and answered many times. The advanced search will become your best friend. Please don't hesitate to ask something that you can't find.
Read the TM 9-2320-289-10 Operators Manual to find out how a stock system should work. It is simular to the Operators Manual for Civilian vehicles. It tells you where all the lighs, switches, etc are located and what they do.

Three of the most important tools you can buy are:
Voltmeter and know how to use it - ~$10 and up
12v Battery Charger - ~$50 for a decent one
Battery Load Tester - ~$30 for an okay one at Harbor Freight

Warthog

 

[TGP (IL)]

So you missed the fact that they were links!

Your reply is much more understandable knowing you missed the links.

Do you have a better understanding of thet GP system now? Or need more info?

Thanks. Yes,I truly missed the links.
I went and got my laptop and can see there orange indicating links.
The glow plug system is not new to me. I understand it fully.
Have Had K 30 Chevrolets since the 14 th one off the line in there debuted year 1977.
I thought from what I have read and learned was that they were 12v,as with everything else,except the staring system and one alt.
Just hard for me to believe that with no load on the resistor you will get full voltage.
If that's the case I can certainly understand why they don't last.
I think I will pull the covers off to make sure it's wired correctly.
Have also found all the TM links and read the FAQ.
Thanks for your help And I sincerely hope my apology is accepted for my remark and appearing to be a idiot.
TGP

 

[Warthog]

Don't worry about it. You can delete that post if you want to, or edit it.

 

[Barrman]

Just to make something clear because you will be working on them soon if your truck follows the pattern most of our have. The truck has a pair of 12 volt alternators. They are both isolated ground 100 amp SI27 units. Drivers alternator charges the front battery and runs all the truck systems found on a regular Chevy. Passenger side alternator charges the rear battery and is there to split starting, glow pluging and slave cabling with the front battery.

 

[TGP (IL)]

Just to make something clear because you will be working on them soon if your truck follows the pattern most of our have. The truck has a pair of 12 volt alternators. They are both isolated ground 100 amp SI27 units. Drivers alternator charges the front battery and runs all the truck systems found on a regular Chevy. Passenger side alternator charges the rear battery and is there to split starting, glow pluging and slave cabling with the front battery.

Thanks.
So is it normal to have 24.5 Volts at the Passenger side Alt. engine off not running.
I just got 8 new plugs to install still can't imagine after there in, they will drop the voltage at the relay from 24V to little above 12V.
Also everything else works as it should.
All lights come on and go out on the dash after starting.
Thanks.
TGP

 

[Warthog]

Thanks.
So is it normal to have 24.5 Volts at the Passenger side Alt. engine off

Yes. You are reading the combined voltage of both batteries.

This is due to how the alternators are wired in series.

With the resistance in the glowplugs and the LARGE resistor on the firewall, the voltage will drop to 12v.

Alot of guys will bypass the resistor and wire the glowplug relay to the 12v terminal post next to the relay. That way if one glowplug fails it doesn't take out all the others.

 

[Barrman]

Put the negative lead of your volt meter on the negative of the rear battery. Then check the power lead on the passenger alternator. Should be 12.6 volts or so with everything off and 14.4 volts with it running.

The wiring system really is pretty easy to figure out. Once the light bulb in your head goes off when you understand how it works together. Until then, you will be confused. Probably.

 

[TGP (IL)]

Thanks Guy's,
Yes I have 12V at that Alt.,using there Battery Ground like you said.
I just finished installing the 8 GP's and it starts perfect.
Now the volt meter drops while the GP cycle,and I have a belt squealing until it catches up.
Which tells me there working.
Now to install new belts. these are shot and out of adjustment.
I am slowly figuring out what they have done to this electrical system. Like you said it really is simple the theory there using.
I am fairly knowledgeable in Automotive electrical wiring.
Really just enough to be Dangerous I guess LOL!
Thanks Again,
TGP

 

[TGP (IL)]

Oh,
And one more thing I got the AC Delco 60G glow plugs as suggested here.

No one said the wire connector is too narrow to slide on the wider tang?
Nothing a little grinding couldn't fix.
Thanks
TGP

 

[mistaken1]

A resistor will not develop a voltage drop until there is current flowing through it, ohm's law E=IxR.

 

[cornrichard]

Mistaken1 That graphic is awesome. I Know ohm's law but always have to try 3 or 4 different combos on my calculator until I get an answer in the range I know is right. I am going to print that and put a copy in my car, house, and shop. I should probably put one in the deuce too.

 

[tbearatkin]

Unless you have $80 to spare and want to spend that everytime you burn out your glow plugs I would get rid of the resistor on the firewall behind the air cleaner and send 12V to my GP relay. Some use the 12v's near the GP relay I connected it directly to my front battery because I did not want to overload any wiring when I powered up all 8GP at the same time. Here is the string of post on how I solved my problem thanks to help from here.

http://www.steelsoldiers.com/cucv/56682-what-why-did-smoke-2.html