Glow Plug Question

[chevy6two]

Am I supposed to be getting power at the bottom post of my glow plug solenoid with everything turned off?

Something is draining my batteries and I found power at that point. Possibly the culprit?

I have a glow plug relay like the ford starter solenoid..

Thanks for any help.

 

[Warthog]

You are not suppose to have power at the terminal going to the glow plugs.

you more than likely have the wrong type of relay. You can only tell for sure by testing it. The small terminal should not be using the mounting bracket as a ground if so your glow plugs will be on all the time and burn out quickly.

we have many helpful threads in the CUCV Helpful Threads sticky. One of those explains how the CUCV glow plug system works. It is different than the civvy units.

 

[chevy6two]

You are not suppose to have power at the terminal going to the glow plugs.

you more than likely have the wrong type of relay. You can only tell for sure by testing it. The small terminal should not be using the mounting bracket as a ground if so your glow plugs will be on all the time and burn out quickly.

we have many helpful threads in the CUCV Helpful Threads sticky. One of those explains how the CUCV glow plug system works. It is different than the civvy units.

This is how the system is hooked up. This is how it looked when i got the truck. The glow plug module has been bypassed.

What I have looks nothing like this..

The way its setup now..it definitely has a ground on the bottom pin going to the mounting bracket. Which you say is wrong.

While piddling around i unplugged both wires from the small terminals on my solenoid and was STILL getting power to the large terminal where my glow plug wires come from.

 

[chevy6two]

Back Again (glow plugs)

Here is a video showing my glow plug system and its readings. Bear with me Im a noob. I dont believe it is performing as it should. Looking for some advice or corrections. Ive researched Electrical Diagrams and have come as close as I could. I believe the previous owner did away with the glow plug module as I havent come across any wires leading to one.

Just replaced the glow plug relay with a starter solenoid from Advanced Auto Parts #S603 as per the CUCV General Information document found in the files section of the facebook page 'CUCV Tech & Discussions'.


https://www.youtube.com/watch?v=D6gqxzYMISs&feature=youtu.be

 

[eme411]

your resistor bank behind the air cleaner is missing,

 

[cpf240]

Some of this was hard to see clearly in the video, but...

That looks like you are connecting to the diamond-shaped 12v buss for power, but you are showing 24v there. I think you have the power to that 12v buss coming from the wrong place. As eme411 said, the resistor bank that sits on the firewall behind the air cleaner is missing, and in that case, the glow plugs should only be fed with 12v, if using stock-type glow plugs. Also, the rest of the truck gets its 12v feed from that diamond-shaped buss, so if it is really getting 24v, then the rest of the truck is over-voltage.

If the small terminals on the solenoid are isolated from the mounting tabs, as it should be, then you need to ground the other small terminal to complete the circuit to energize the solenoid.

On another note, that looks like the freebie HF multimeter. They are not the best, and it may just be reading stray voltage in that one part of the video.

--Yeah, looking at that video, the red wire going from the 24v buss to the 12v buss is wrong, it needs to go to the hot of the front battery to provide 12v to that 12 buss.

 

[chevy6two]

What your saying is the diamond-shaped buss should only be getting 12v? In my case im getting 24v, which is due to the resistor bank missing?

The power to the diamond shape buss is coming directly from the positive battery bus bar.

Warthog told me in a previous thread "The small terminal should not be using the mounting bracket as a ground if so your glow plugs will be on all the time and burn out quickly."

Can I ground the small terminal to the firewall or something?

 

[cpf240]

spelling

The diamond shaped buss is the 12v buss for the truck. In stock wiring, the front battery neg post goes to ground ( small gauge wire to the core support, heavy gauge wire to the ground buss under the 24v buss ), the pos post goes to the neg post of the rear battery with a tap off to the 12v buss. The rear battery pos cable goes to the 24v buss.

In the stock system, there is a wire from the 24v buss to the resistor bank, and then the other side of the resistor bank has a wire going to the glow plug solenoid. The combination of the resistor bank and the glow plugs form a voltage divider circuit, resulting in the glow plugs seeing 12v. Many people bypass the resistor bank and connect the glow plug relay directly to the 12v buss, as you have done, to help prevent a situation known as "cascade failure" of the glow plugs that can happen in the stock configuration.

What Warthog said is correct for the stock glow plug system. Since you are not using any part of the glow plug controller wiring, you can wire it the way you have it, but you'll need to ground the other small terminal. In the stock configuration, one small terminal has 12v on it, and the glow plug controller card activates the glow plug solenoid by providing a ground to the other small terminal.

Take a look at the wiring diagrams to see the battery cable configuration, etc.

 

[chevy6two]

Thanks for all the info. That really did the trick. I took that hot wire from the 24v to gp solenoid and connected it to the neg terminal on my rear battery. Also i grounded the lower small terminal on gp solenoid. Im getting 12v, that clink sound from the relay and a positive reading at the end of the gp connectors.

With that being said, i ran into another problem. Haha. Turns out my starter button sticks and i bout caught something on fire. I hustled to discconect my pos and neg posts on battery as what looks like the grounding wire on my alternator was frying.

I need to get a fire extinguisher...

Hope i didnt ruin my starter.

 

[chevy6two]

The diamond shaped buss is the 12v buss for the truck. In stock wiring, the front battery neg post goes to ground ( small gauge wire to the core support, heavy gauge wire to the ground buss under the 24v buss ), the pos post goes to the neg post of the rear battery with a tap off to the 12v buss. The rear battery pos cable goes to the 24v buss.

In the stock system, there is a wire from the 24v buss to the resistor bank, and then the other side of the resistor bank has a wire going to the glow plug solenoid. The combination of the resistor bank and the glow plugs form a voltage divider circuit, resulting in the glow plugs seeing 12v. Many people bypass the resistor bank and connect the glow plug relay directly to the 12v buss, as you have done, to help prevent a situation known as "cascade failure" of the glow plugs that can happen in the stock configuration.

What Warthog said is correct for the stock glow plug system. Since you are not using any part of the glow plug controller wiring, you can wire it the way you have it, but you'll need to ground the other small terminal. In the stock configuration, one small terminal has 12v on it, and the glow plug controller card activates the glow plug solenoid by providing a ground to the other small terminal.

Take a look at the wiring diagrams to see the battery cable configuration, etc.

Hey, one more thing..
Now that I have the 12v buss wired correctly from the rear battery neg terminal, let me note that my alternator was also wired to that 12v buss. I got the truck with only 1 alternator. I havent checked but Im assuming its a 24v alternator. With that being said, my 12v buss is 12v now instead of 24v. That would mean my alternator is only getting 12v..not enough to charge two batteries. right?

I was looking at the wiring diagrams for the charging system for the M1010 and it shows it with 2 alternators. So someone got rid of the driver side alternator in my truck.
What I gather from the wiring diagram is instead of the driver side positive terminal going to the 24v buss, my passenger side alternator positive terminal should goto the 24v buss instead. The negative terminal is my ground. Does it have to ground to the engine or can i ground it to the chassis?


---http://www.motormayhem.net/wp-uploads/2009/11/maintenance-manual.pdf
page 863

 

[cpf240]

If the truck came with only one alt, perhaps someone did a 12v conversion on it already? If so, then your batteries would need to be wired in parallel, not series, and then one 12v alt would charge them both. In which case, what was the 24v buss would be a 12v buss and your wiring of the diamond-shaped buss to the ( originally ) 24v buss would have been fine. You'll need to find out more before you proceed. Maybe take the alt and starter in to an auto electric shop and see if they can determine if they are 12v or 24v parts, etc.

 

[bwilson7990]

According to an earlier thread he claims he was reading 24V coming off that POS term board. That would make me think either the single alternator is a 24V charging both batteries or hes got a 12V alt charging one battery which eventually spills over to indirectly charging the other battery because of the way they are in a series? Not sure about that. Definitely need to get the items tested to see what's being worked with and go from there.

 

[MarcusOReallyus]

According to an earlier thread he claims he was reading 24V coming off that POS term board. That would make me think either the single alternator is a 24V charging both batteries

Yes, I wondered the same thing.

or hes got a 12V alt charging one battery which eventually spills over to indirectly charging the other battery because of the way they are in a series? Not sure about that.

Nope. That would require magic. (Or an inverter, which isn't out of the question, but it would be obvious.)

Definitely need to get the items tested to see what's being worked with and go from there.

Yes indeed! Got to find out what's really going on here. Sumthin' ain't right.

 

[chevy6two]

If the truck came with only one alt, perhaps someone did a 12v conversion on it already? If so, then your batteries would need to be wired in parallel, not series, and then one 12v alt would charge them both. In which case, what was the 24v buss would be a 12v buss and your wiring of the diamond-shaped buss to the ( originally ) 24v buss would have been fine. You'll need to find out more before you proceed. Maybe take the alt and starter in to an auto electric shop and see if they can determine if they are 12v or 24v parts, etc.

well I took the alternator off and brought it to advanced autoparts. he ran the alternator as a 12v alt and really couldnt tell me if the alternator was 12v or 24v. but it did come to say there was a bad diode in the alternator. so i took it to oreilleys to see what they would say. the woman there said she wouldnt be able to tell me or test it bc they only have a tester for 12v and that if it was 24v it wouldnt say.

so anyhow i went ahead and put the alternator back in the truck(i just want to hear the truck run!). (No I havent taken the alternator or starter to any auto electric shop just yet). I wanted to see the engine run so i assumed the starter and alternator were 12v (bad idea?). it really does appear to be a 12v system though. everything the way the system was hooked up when i got the truck was just like what the 12v conversion helpful thread said to do: 1 alternator, a missing resistor behind the air filter and an 8 gauge wire from the positive junction box to large stud on 12v buss.

With that being said..

when the 12v conversion instructions said to hook up my batteries on the last steps, it says to hook my battery cable from the positive terminal on rear battery to positive terminal on front battery. The rear positive terminal should already be hooked up to the positive junction box. So I did that. Next I was to take a battery cable from the neg terminal of my rear battery to the negative junction box. Lastly hook a wire from front battery negative terminal to the the negative junction box.
Well, when I hook the rear negative terminal to the battery a spark is made and my starter proceeds to spin..

My key is turned off and I even went as far as to unplug my starter push button thinking it may be stuck, i dont know..

Not sure why its doing this. Any ideas?

BTW here is my reference on 12v conversion..
www.steelsoldiers.com/showthread.php?145322-CUCV-Rosscommon-24v-to-12v-Conversion

 

[bwilson7990]

It sounds like you have an incomplete 12v conversion.. I would decide what you want your end result to be (12v w/ 1 alt, two 12v isolated w/ 2 alts, or 24v w/ 2 alts) and start from scratch to make it however you'd prefer it to be. This way you can go over every step from the beginning and ensure that all variables in the system are accounted for. This means wiring everything according to the approach you are taking (or verifying everything that's been done already), getting a matching starter, and getting that alternator rebuilt so that you know it's 100% functional. Definitely have it rebuilt over buying new though. The quality of the original 100amp alts far surpass what you'll buy in autozone/advanced today. I'm almost certain that the stock system uses two 12v alternators (someone please correct me if I'm wrong) so you should be fine to just use the single remaining alternator for a 12v system if that's what you go for. I wouldn't be surprised if you find other issues with the GP system, or any of the other systems directly connected to that diamond-shaped engine harness block since you were reading 24v there and it's designed to be 12v at that block. You'll just have to do some further electrical testing if you run into issues. The same thing was going on with my 1008 due to the bad resistor pack on the firewall and I'm in the process of completely re-doing the entire GP system from scratch because of it.

Also, you're starter could be spinning when you connect your circuit as you described above with no key or anything else if the relay is stuck closed. It should only be active with iginition (key turned on) but if an electrical surge welded the gate shut you wouldn't need ignition to pass current through it. This relay is behind the dash on a little shelf to the right of the steering column next to the GEN2 relay. It seems the most popular fix for this is the Doghead starter relay mod. A quick forum search will find that easily.

Replace that relay, test/replace your starter, rebuild the alt, wire everything up carefully to achieve the electrical configuration that you want, and test from there. That's your safest bet as far as trying to get this corrected without damaging anything else electrical in the truck.

Lastly, make sure you keep the batteries charged throughout your testing to avoid draining them to no return. And it goes without saying but be very careful with this stuff; there's some serious current/amperage going on with these trucks that can be very dangerous.

 

[cpf240]

It does sound like it has been converted. I would hook the batteries up in parallel, as you described. That would include the wire to the 12v buss from the old 24v buss.

For the starter issue, is your push button going directly to the starter solenoid, or through the starter relay under the dash? Either one could be stuck in an "on" position.

 

[chevy6two]

It sounds like you have an incomplete 12v conversion.. I would decide what you want your end result to be (12v w/ 1 alt, two 12v isolated w/ 2 alts, or 24v w/ 2 alts) and start from scratch to make it however you'd prefer it to be. This way you can go over every step from the beginning and ensure that all variables in the system are accounted for. This means wiring everything according to the approach you are taking (or verifying everything that's been done already), getting a matching starter, and getting that alternator rebuilt so that you know it's 100% functional. Definitely have it rebuilt over buying new though. The quality of the original 100amp alts far surpass what you'll buy in autozone/advanced today. I'm almost certain that the stock system uses two 12v alternators (someone please correct me if I'm wrong) so you should be fine to just use the single remaining alternator for a 12v system if that's what you go for. I wouldn't be surprised if you find other issues with the GP system, or any of the other systems directly connected to that diamond-shaped engine harness block since you were reading 24v there and it's designed to be 12v at that block. You'll just have to do some further electrical testing if you run into issues. The same thing was going on with my 1008 due to the bad resistor pack on the firewall and I'm in the process of completely re-doing the entire GP system from scratch because of it.

Also, you're starter could be spinning when you connect your circuit as you described above with no key or anything else if the relay is stuck closed. It should only be active with iginition (key turned on) but if an electrical surge welded the gate shut you wouldn't need ignition to pass current through it. This relay is behind the dash on a little shelf to the right of the steering column next to the GEN2 relay. It seems the most popular fix for this is the Doghead starter relay mod. A quick forum search will find that easily.

Replace that relay, test/replace your starter, rebuild the alt, wire everything up carefully to achieve the electrical configuration that you want, and test from there. That's your safest bet as far as trying to get this corrected without damaging anything else electrical in the truck.

Lastly, make sure you keep the batteries charged throughout your testing to avoid draining them to no return. And it goes without saying but be very careful with this stuff; there's some serious current/amperage going on with these trucks that can be very dangerous.

I want it to stay a 12v 1 alt system. However whoever modded it did away with the starter relay. i have a wire going from the starter to the push button switch. from the push button switch to a toggle switch, and from the toggle switch into an abyss of wires..

My glow plug system seems to be working fine as long as it gets 12v at the solenoid. I dont know what would make something stuck to let the circuit run thru.

For the starter issue, is your push button going directly to the starter solenoid, or through the starter relay under the dash? Either one could be stuck in an "on" position.

Yes the push button goes to starter. There is no relay.