LB7 Glowplug issue

[catman3126]

I have an LB7 that is not turning the glow plugs on I can check with a meter when I turn the key on and no voltage is being sent to the glowplugs I have power to the lug on the top but doesn't seem to be activating the relay to send power to them. it is a Cali emission LB7 also. does the relay get its ground through the mounting hole that has metal in it? and what are the four wires in the center plug doing? I have voltage on 3 of them and a ground on one. if anyone has a wring diagram for this that would be great also I have deleted the AIH and its relay.

 

[tgebes]

I do not know much about the cali emmision set up but when mine was not working I found the eyelet going to the glow plug relay from the hot post on the controller had melted, right at the eyelet. It was throwing a check engine light as well. I would just check the controller over real well, lots of wires going every which way with high current.

 

[juddski88]

You can just swap the relays for now and see if that fixes it. The other relay is just for the heater. Also, just to be sure, check the maxifuse.

 

[catman3126]

Maxi fuse are you talking about the 175 amp fuse under the fuse box cover? I have good power to the go controller do I have to keep the relay plugged on for the intake air heater to make the go controller working?

 

[dmaxbowtie]

i have a cali emissions glow plug module not sure what they are worth but if you end up needing one shoot me a pm

 

[juddski88]

I could be wrong, but I do believe it needs to be plugged in to complete the circuit, even if the relay doesn't work properly.

 

[THEFERMANATOR]

You can just swap the relays for now and see if that fixes it. The other relay is just for the heater. Also, just to be sure, check the maxifuse.

The CALI controller is COMPLETELY different from the federal one. Wish I had a wiring diagram for the differences between them, but all I have is my 01 which was strictly federal.

 

[catman3126]

got it figured out.

1-Air heater relay does NOT need to be plugged in,
2- The controller somehow knows if the GP's are bad because it doesn't sent power if they are
and this thing had all eight GP's bad. after I found that there was no power besent to them I OHM's one and it was open so I removed it and hook up jumper cables and nothing so I took one out of the old more and did the same it lit up right away, so as I removed each one I OHM's them and jumper cabled them and all were open, no I first thought I wonder if somehow the controller is bad and continued to send power until they burnout out but after I started it up with my meter connected it sent power for the normal amount of time and shut off. this motor was from a wreck yard and was said to have 16k on it is all but I know they removed the glow plugs to do a come test as I could see the signs on the hex that they were loosened. so I don't know but hope this fixes it so as of right now they are working. thanks for the help

 

[THEFERMANATOR]

The LB7 controller is basically 8 relays in one from my understanding, and if the ECM senses a problem it doesn't command that one on. Odd to have 8 bad ones, they must have had the glow plugs on with a starter charger hooked to it.

 

[catman3126]

Actually the glowplugs were the ones that came with this lly engine I swapped into a lb7 rig with lb7 electronics so the controller could have been bad in the diner rig. I believe they were bad when I got this engine

 

[juddski88]

So you pinned the old controller into the correct pins in the bale connector right?

 

[juddski88]

The CALI controller is COMPLETELY different from the federal one. Wish I had a wiring diagram for the differences between them, but all I have is my 01 which was strictly federal.

There's still the 2 main relays that mount next to the bale connectors like the federal trucks

 

[catman3126]

I used the lb7 harness and made harnesses to if into the lb7 harness and adapted the to the lly injectors so I uses the harness and controller for the truck that I put the engine in, there was only one relay on this rig for the air heater and it got its power from the lug that the main power was supplied the controller, as soon as I changed the glow plugs it started sending voltage for around ten seconds I will see how it starts in the morning since it is getting down on the teens here at night, I know for a fact it is sending power and before it was not

 

[THEFERMANATOR]

Are you using LLY or LB7 glow plugs? If your using the LB7 controller you have to use 11 volt glow plugs. I believe the LLY uses 4.7V glow plugs which would explain why all 8 quit.

 

[dmaxbowtie]

glad to hear you've figured it out. iirc you could read engine codes on efi live and it would tell me individually which glowplug was bad when i had the cali emissions.

 

[catman3126]

yeah didn't have any individual codes just the p0380 no glowplug feedback or something

 

[THEFERMANATOR]

LB7's don't tell you which glow plug failed like the newer trucks do, they just give you the P0380 code. Sounds to me like you used the wrong glow plug controller combo and took out the LLY glow plugs. I hope you put 62G's back in it of your using the LB7 controller, otherwise the 63G's are going to fail right away again.

 

[juddski88]

I use Lly glows with my lb7 controller. I blow relays when I have low voltage....never blown a glow plug yet.

 

[dmaxbowtie]

LB7's don't tell you which glow plug failed like the newer trucks do, they just give you the P0380 code. Sounds to me like you used the wrong glow plug controller combo and took out the LLY glow plugs. I hope you put 62G's back in it of your using the LB7 controller, otherwise the 63G's are going to fail right away again.

Im almost positive that when i had the cali/egr engine in my truck that it would tell me which glow plug were bad? (had individual wires to each glowplug and not one of those bars connecting them all also) Regardless his didnt throw individual codes so its of no help to him.