cucv glow plug controler and 12v conversion

[doghead]

It does not sound bad to me. It sounds like you have the resistor bank still installed. It needs to be eliminated. when you convert to 12volts.

The system switches ground to the relay to activate it.

 

[rnbebout]

Ok, Dog head, were is that? I will try removing it to see if that works!

 

[doghead]

Post # 13 said where it is.

Follow the supply wire, and see if there is a large resistor set inline.

Post a picture of your firewall or open a technical manual and look at the pictures to identify it. Also a search on this site may help.

 

[rnbebout]

I have a block on the firewall behind the air filter, that is in the middle of the supply cable from the battery to the GP relay. It is on a bracket plate mounted to firewall!

 

[doghead]

The first 2 pictures in the first post of this thread shows it. http://www.steelsoldiers.com/showthread.php?32567-What-happened-here-glow-plug-resistor-bypass

 

[rnbebout]

doghead, I saw those pics and yes thats what my truck has going on!! Thanks for ALL the help. I am brand new here, so thanks again!!!

 

[doghead]

In a stock truck, the resistor combined with the glow plugs cause a drop from 24 to 12 volts.

When you are only supplying it with 12 volts, it drops closer to 6 volts(not good).

So, with the elimination of the resistors, you send 12v and get 12 volts. All is good like this.

 

[cpf240]

Sorry, missed the bit where the truck was converted to 12v. Never mind... nothing to see here, move along...

 

[rnbebout]

Hello, I've got another possible issue! Since i took out the resistor, the truck now seems to be running the batteries down some when it sits for awhile,(6+ hours)! ALSO, when the truck is good and warm, it cranks good but has to crank for an extended time to fire up!

 

[rnbebout]

It does have a brand new fuel pump and filter in it.

 

[doghead]

Unfortunately with it being converted to 12 volts by someone else, we have no idea how it was done and therefore can't really help with a simple/systematic diagnosis.

Maybe some pictures would help.

Removing the resistor should not have changed anything other than it eliminated a voltage drop when the GPs are on.

 

[rnbebout]

I understand no problem I'll probably just put a heavy duty switch in the middle of the battery lead to the relay for the glow plugs cut the power completely to that relay until I will need it.

 

[rnbebout]

I think the difficulty in cranking it when it's warm is fuel backflow somehow I'll probably just try to find anti-backflow valve to put in the fuel line close to the filter.

 

[MarcusOReallyus]

I understand no problem I'll probably just put a heavy duty switch in the middle of the battery lead to the relay for the glow plugs cut the power completely to that relay until I will need it.

Take some pictures and post a description of how it's wired, and we can probably help you figure it out.

 

[rnbebout]

Hello, I'm back with another question! My glow plugs are working great, starts fine after waiting for a click; glow plug solenoid. Have to listen for the click because the (wait to start light) doesn't work Any idea where to check for the wire that goes to it?

 

[antennaclimber]

Try checking the bulb first and all of the fuses.

The dark blue wire from the GP card is a switched ground to the Wait light. See if it pulls (switches) to ground when the wait light should be on.

The pink/black wire going to the wait light is the positive side. See if it has 12 volts on it, if not then you may simply have a blown fuse.