No voltage at cold advance leads - Glow Plug Module faulty?

[nudewheeler]

Howdy Folks -

The big green turd has been quite the SOB to start lately. There is no voltage at the cold advance or fast idle leads that connect to the injection pump.

I have replaced the thermo-swtich at the rear of the passenger's side of the block that threads into the block that governs when the cold advance/fast idle leads get voltage. The thermo switch it good.

I tested voltage at the cold advance/fast idle leads at the injection pump - nothing. I tested voltage at the leads that plug into the thermo switch (I believe these leads come from the controller card, based on diagrams F-3, F-4, and F-7.)

To further explain, F-3 Engine Compartment Ignition Circuits, in the upper left of the diagram you see the cold advance control and temperature switch. I tested voltage at both the cold advance control and the col advance temp. switch (.8 LT GRN-936A and .8 LT GRN-936B. Nada, 0 volts. Further towards the source of power, .8 PNK/BLK-39B(SXL) traces to the glow plug module - this is the entirety of my question to this thread)

Is the GLow Plug Module faulty? Gone to shiznitz?

I have verified all fuses in the fuse box are good. I see no other potential causes why the there is no voltage to my cold advance leads.

Any other ideas? Is this how glow plug modules typically fail? What other symptoms can I expect if the Glow Plug Module is on it's way out?

Any suggestions where to purchase a new Glow Plug Module if this one is faulty?

Cheers and thanks in advance,

S

 

[dependable]

I'm pretty sure the supply lead to idle speed temp switch is on engine compartment harness, not glow plug circuit. Check TM9 2320-289-34, pg e-5. I had a problem with this once and the wire to the switch was broken, but the insulation was still intact and crimped to switch lead. The pink/black wire you need to test comes from engine circuit and also splices (mid harness) to water in fuel sensor, I think.

 

[mistaken1]

PNK/BLK-39B splices and becomes PNK/BLK-39A that terminates on a fuse (20A engine control) to power the circuit in question along with a number of other circuits.

 

[nudewheeler]

Welp Howdy Guys -

I see the PNK/BLK-39A / PNK/BLK-39B splice on E-4 (All except M1010) of the -34TM. I must be failing to spot the temp sensor 'dependable' is referring to. Can someone please help me find this in the wiring diagrams, and maybe a quick description where this is found on the M1009?

As some side notes, the seatbelt buzzer and timer is not connected to my fuse box (bought it like that, plugged it back in, found it very annoying, and disconnected it again).

Also, I have converted the fuel filter to a spin on using some of the NAPA components mentioned on a few of these threads. All of the connectors that formerly lead to the old fuel filter plate are loose in the engine compartment.

The injection pump was replaced by a mechanics shop (Central Motive) in albuquerque NM. They used a Standyne DB2-4510 pump. I did some research on this, and it appears to be a 'high altitude' injection pump. The only major difference I see between the standard M1009 injection pumps and this DB2-4510 is the DB2-4510 has only 2 electrical spades on the housing. One is for the fuel shutoff solenoid, and the other is for cold advance (I am guessing, it could be fast idle as well). Anyways, my IP can not use all three leads from the standard harness. One of either the cold advance or fast idle is left unattached. Refer to one of my past threads for IP pictures http://www.steelsoldiers.com/cucv/73993-engine-stalls-after-cold-startup-after-throttle-blip.html

So, on E-7 (All except M1010) of the -34 TM, the .8 PNK/BLK-39A (SXL) that originates from the Glow Plug Module is unrelated to the Cold Advance and Fast Idle leads??

 

[txmytx_catahoula]

You wrote that you tested the voltage at the Thermo switch but you didn't state the result. I had a problem like this, had voltage to the switch but not to the fast idle and the switch was good. In my case, all the connectors were corroded. A quick clean up and everything worked. If you're not getting power to the switch there has got to be a break in the power supply to it, somewhere.

 

[dependable]

Sensor is a 2 prong thermal switch on right (passenger side), way in the back, behind the exaust manifold.

 

[nudewheeler]

'Dependable' indicates there may be more than one switch to troubleshoot. I was troubleshooting Cold Advance Switch:

2 PAOZZ 11862 14071047 SWITCH,COLD ADVANCE 1

As seen in on figure 54 on page 54-1 of TM 9-2320-289-34P (The intermediate parts manual).

I replaced this switch (and tested both old and the new. Appears the thermo switch opens right around 120 deg. F). There is no voltage before this switch (tested the leads that plug into this switch) nor after this switch (at the cold advance / fast idle connectors at the IP).

 

[txmytx_catahoula]

The pink/black wire traces back to a big connector at the fire wall. You'll have to remove a bolt to open it, but you might see if the power makes it through the connecor. TM-20 figure F-3. Then back into the cab figure F-4.

edit: Depending on how you disconnected the seatbelt buzzer, you might have cut the power to the switch. They are both fed power on the same circuit (pink/black wire).

 

[mistaken1]

As some side notes, the seatbelt buzzer and timer is not connected to my fuse box (bought it like that, plugged it back in, found it very annoying, and disconnected it again).

edit: Depending on how you disconnected the seatbelt buzzer, you might have cut the power to the switch. They are both fed power on the same circuit (pink/black wire).

There it is.

 

[nudewheeler]

To add closure to this thread:

Mistaken is correct, once again. Plugged the buzzer into the fuze box and 10.5 volts appeared at the cold advance leads for the injection pump while the key is turned to ignition. Bingo.

Now, my buzzer kept buzzing, in all conditions. The open door sensors, are not wired to anything in the M1009s. I believe I caught a phrase in the -34 TM that the M1010s have the door sensors wired.
Eliminated open door sensor as the buzzing culprit.

Searched at the seatbelt, and found some cut wires near the base. Connected them together to no avail, still a continuous buzz.

Flipped through a a few threads on here to find some solid state longer rectangular 'thing' that connects to the turn signal and ignition somewhere. Reference this hyperlink http://www.steelsoldiers.com/cucv/41725-part-steering-column.html Bought my M1009 with a whacked turn signal stalk and switch. Figured this part must have been overlooked or damaged in the melee.

Anyways, didn't have enough beer to motivate me ripping into the column to try to find this little bugger part, so we thought outside of the box and wanted to kill the buzz at the buzzer.

Now, my buzzer is located atop the fuse box. There is a retaining clip on the top of the buzzer that, if you pull up on the retaining clip and outward (toward the rear of the vehicle) on the buzzer, the buzzer comes out. The buzzer has four male spades that connect to its connector. After opening up the buzzer to see how it worked, and creating 2ft extension leads for each of the 4 spades to the buzzer, we conducted an experiment.

Which spades may be disconnected to kill the buzzer, while still providing voltage to the cold advance leads through the voltage passthroughs of the remaining 3 spades? The answer: the right most lead, or lead furthest towards the passenger side of the vehicle. What a turd...

So, if your buzzer buzzes continuously and you've disconnected it, and your truck is an SOB to start in cooler weather, this thread will hopefully help you.

Bend the right most (farthest to the passenger side) tab on the buzzer so it cannot make its connection. Plug that sucker back in, and you're in business.

I put the multimeter inline with the batteries to evaluate battery draw after I modified the buzzer to make sure things were kosher, and I wasn't sucking up current silently with the buzzer. No keys in the ignition, total draw on the electrical system was .2mA. Conservatively estimating each battery has 40amp hours, the truck should be able to sustain this minimal draw for ~45 years. Should still have charge even after the zombies come.

Thanks for your contributions everyone!

 

[appalacious]

wowzers....

well done, guys.

I can't say that everything is clear to me on this. When I look at the diagram it sure looks like the seatbelt buzzer is in parallel with the cold advance temp switch (rather than series), but if it works it works...