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Throwing codes again!!!

Sinners Saint

Sinners Saint

New Member
Messages
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Location
Houston, Texas
Alrighty then, today I went to have lunch with my girlfriend and noticed the speedo and tach gauges would jump up and down several times, was even doing it when the truck was'nt running with the ignition on. It would stumble and hesitate on take off. I checked the codes and it was 18,35, and 54. I had similar codes when the PMD went out. The new one has'nt been on the truck for long and I mounted it behind the bumper with the PMDCABLE.com kit. A few things I recently did where, replace the OPS and modded the turbo boost controller(made it manual). So could the PMD be going out again? Could the new OPS be an issue?
 
With the tach and spedo acting funny with the truck not running, I would be thinking electrical. Think grounds and connections.
 
Agree with all of the above.

In additiong, check your alternator? Tach signal comes from alternator. That is what it did when my alt on its way out.
 
Cleaned and reattached the grounds on the engine and batteries yesterday. Did'nt get a chance to drive it til today and it was running fine, until, I left the Dr. offices and the gauges quit working suddenly when I got the truck started. No warning lights, no glow plug light, no speedo,tach,oil,temp or voltage gauges. The only one still operating is the fuel gauge. WTF!!! I'm bout to pull whats left of my hair out! I can't even check the codes now cause the SES light is'nt even working. The picture is with the truck running sitting in the parking lot of the doctors office.
 

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Does the truck start and run when no SES and gauges? Test or change out the ECM fuse, and the gauges fuse under the steering column.

Check to make sure the ALDL pin A (top right) is a good ground. Ohm it out to the chassis, needs to be less than 1 ohm.
 
Yep truck runs without the gauges and ses light. The backlighting in the cluster works, but the gauges aren't reading out. Thanks for the tip, I'll check it out.
 
If its running then the ECM fuse is fine, but the Guages fuse could be suspect. Or that ignition switch contact, but 94 isnt know for switch issues. Could be the Instrument Panel connector as mentioned before, but I would think a ground more likely.

Once you test the Gauges fuse and ALDL ground, make sure there is a ground wire secured where the ALDL port attaches under the dash and that there are two good grounds on top of the engine at the rear of passenger side, on an intake bolt and a water blockoff plate bolt. And there should be one more on the back of the engine near the fuel filter manager.
 
Went to crank the truck this afternoon to go to the store and it won't start now. Checked the fuses, the gauge fuse is blown, can't find whats doing it. The ECM fuse was fine. I've pulled and cleaned the grounds. nothings gotten anybetter, just seems to be getting worse.
 
My offer in our PM's still stands, if you can get the truck down here (he's local) and want to try another PMD let me know. I have not had a single problem with the Dtech PMD's, but there is a first time for everything.

Other option, send me your PMD and I will see how it works on my truck.

Leroy
 
Doubtful its a PMD. Is it cranking at all? Or any other symptoms?

Did you test the ALDL port ground to chassis?

There is a 23 pin bulk head connector. It is between that ALDL DLC pin A and the ground. If you dont have good continuity from there to chassis, then it also provides ground to Park/Neutral Switch, and wont start without that grounded most likely.

If you didnt find all three grounds, one of those was the PCM/LP ground. Does the LP work (pump fuel out the drain) if you jump the LP fuse on the firewall to a battery junction post? I think it is the ground on the coolant block off plate.
 
The grounds are all ok, I've cleaned them all and made sure they all have good connections. Could a bad glow plug controller be the problem?
 
It can be anyhing, have you tested your alt as suggested above?
Clean the cluster ground? These are not the engine ground.

Take up Leroy's offer to test the PMD to eliminate 1 problem.

It can be the LP goes bad, happened to me.
It can be the GP controller.
 
The Gauges fuse does go to the GP controller, as well as the instrument panel and cruise control. It would have to be nasty cold for the truck to not start without the glows. It would end up starting after about 10 seconds of cranking unless it below freezing I suppose.

A no start need to check other fuses though, like ECM and Fsol (goes to PMD and Fuel Shutoff Solenoid).
 
Yeah thats my way of saying the glo controller isnt his problem ;), although it could cause the gauges fuse to blow, neither are necessary for it to start the truck.

And the codes he has are becaue his lift pump probably isnt working. Either that or it isent getting power, like an OPS failure. I was looking at the no start and electronics issues though, not the fueling codes. The codes are caused by air or fuel starvation, both likely due to LP failure, and gets worse when filter isnt installed correctly.

That ALDL DLC port ground is the same as the LP I think.
 
I changed the glow plug controller and plugs today and changed the gauges fuse. As soon as the ignition is turned on the fuse blows, and the truck still don't start. I jumped the lift pump and it still puts out as much flow as it did when I got the truck. I can't tell you exact psi cause I don't have a gauge. I've cleaned the grounds on the engine as well. What could be shorting out to blow the fuse?
 
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