G/P Ground

[73m819]

The reason for this cucv love note > http://www.steelsoldiers.com/showth...u-get-the-GP-card-holder-OFF-mounting-bracket is,

I put a new ip, lift pump and spin on filter on Swiss's wheel chock or as some call it a m1009, in doing so I had to pull the intake manifold which included disconnecting TWO grounds from the right rear of the intake, fast forward to start up, NO WAIT light, so started looking, replaced the temp. sensor, still no wait, solenoid works if grounded, so start though the trouble shooting in the TM.
Looking at the G/P wire schematic, THERE IS NO G/P GROUND shown. scrolling though the wiring schematics, I looked at the START wire schematic, it had the G/P module shown, followed the wires looking for a THIN black wire (cucvs use black for ground), after going thought a bunch of twist and turns, splices, blocks, plugs, ect., found that the MORONS that designed this POS hitched hiked the G/P ground onto the "water in fuel sensor ground", this IS the THIN ground that is attaches to the right rear of the intake manifold. There is NO WHERE in the wiring schematics that SHOW the G/P GROUND, The wiring schematics show EVERY conceivable thing that CAN be added to the electrical system and the grounds for them yet these IDIOTS that designed this POS could not show the ground for the most needed system on the truck (without the G/P system working, the truck does not start cold). Anybody but a moron would GROUND the G/P system right there under the dash where the controller card IS instead of running the ground back out to the engine bay (not a direct route either) and then hitch hiking it on another systems ground.

So for you who might need to know WHERE the G/P system GROUND is, now you know.

CAN YOU FEEL THE LOVE

I want to thank, DH, Joe, Leroy, for there patience with my many help/frustrated calls (cucvs WILL cause the POPE to become a Muslim)
and Swiss who lead me to find the MISSING ground.

 

[antennaclimber]

TM-2320-289-20

Appendix F, Figure F-1 Engine Starting Circuits clearly shows the ground for the glow plugs.
It's marked "Ground Strap"

Appendix F, Figure F-7 Glow Plug Circuits clearly shows the ground location for the glow plug module.

 

[73m819]

I sure cannot find " G/P ground" on that page, NO WHERE does it say G/P GROUND or show it, I have looked and looked ???

F1 shows the two ground straps but not stating it is the G/P GROUND,
F7 That ground shown up near the top is NOT the G/P ground, the ground off the intake needs to grounded to make the G/Ps to work.

 

[antennaclimber]

It's labeled "Ground Strap". It grounds the engine block, the engine block provides the ground for the glow plugs.

Correction: This ground strap does not ground the engine. It provides a ground to the vehicle body from the engine.

 

[73m819]

The big wire is the ground strap, the thin one IS the g/p ground, that needs to be grounded, it works if or if not the thick ground strap is attached.

 

[antennaclimber]

The thin wire is not the glow plug ground. It can not handle the 100 amps that glow plugs draw.

The thin wire is the glow plug module ground. If it is not connected the glow plug module will not function properly.

 

[Warthog]

The ground for the controller card is actually at the main ground terminal behind the rear battery. In the above diagram it shows to be attached to the center terminal. It goes to the firewall connector, to the 6-plug connector under the dash and then to the controller card. All of the connections need to be clean.

Very few of the ground connections say "ground".

Now looking at at diagram E-1, tracing the black wire from the controller card back to the engine ground, there is a splice that shares the ground with the water-in-fuel switch.

Looks like conflicting info. Or there might have been a change order.

There is even a sticky in the CUCV forum that lists all the grounds and their location.

Ron are you telling us you forgot to reinstall a ground?

 

[antennaclimber]

I just went out and looked at my M1009. This is how its wired:

Front battery ground goes to the Negative buss bar.
Neg. buss bar has a heavy wire to engine intake manifold bolt. This is the ground to the glow plugs.
Also on the intake manifold bolt connection is the ground strap to the vehicle body and one or two smaller wires.
So the ground strap does not handle the current to the glow plugs. My statement above is incorrect.
Also on the ground buss bar is a wire to the front slave connector and to the rear radio buss if your vehicle is equipped with that option.

Warthog is right, there is conflicting info in the TM and what is really in the vehicles.

 

[Recovry4x4]

Now I feel like a super idiot. I thought the glow plugs achieved ground through contact of their threaded body to the cylinder head? Gheez.

 

[antennaclimber]

Now I feel like a super idiot. I thought the glow plugs achieved ground through contact of their threaded body to the cylinder head? Gheez.

It's all magic.

 

[Recovry4x4]

This must be why civilian heads won't work. Isolated ground heads.

 

[doghead]

24V heads ?

 

[antennaclimber]

24V heads ?

HMMWV heads are 24 volt.

CUCV heads are 12 volt isolated ground.