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help, husband wants to sell it if we can't fix it

okay what is the difference between and fsd and pmd? just where it is mounted? what is the heath version, is there a website? and will the harness have to be waterproof also? I am hoping hubby will have time to check the grounds this afternoon, is there any definitive symptoms that the pmd is out? or is it basically just trial and error? with it happening erratically I guess we do the grounds and if nothing is obvious ride it and see what happens?Thank you so much you all! I will update as I can pursuade hubby to get out in the cold and under the hood!
 
Everyone praises heaths PMD/FSD(same thing) because of its 7 year warranty. Here is a link to his website!
 
I know if fixed my problem, it had just backed off slightly from the contact point and the cruise would think the brake was on, slight rotation and voila, it worked again. Just my experience.
 
To be truthful, I couldn't figure it out myself, the Power Mech instructor at the school I teach at helped me. It took him 5 seconds. He said it just rotates somehow.
 
pmd=fsd, same thing just differant name for it. has the suburban ever stalled out while driving or "bucked" (turned off/on repeatedly very fast)?

pmd 1 year old but relocated to the top of the engine can still die, thats what happened to mine. get it out of the engine bay, away from all sources of heat. mine's relocated to inside the front bumper with a heatsink attatched (pics)
DSCN1406.jpg


inside the bumper
DSCN1407.jpg



clean up the grounds and relocate the pmd, simple and cheap to do.
 
If you plan on keeping the Burb a long time get the Heath PMD Issolator Kit. More expensive but has a warrantee for 7 years.

http://www.heathdiesel.com/P/HDP1280/

That being said the wifes Heath PMD (Stanadyne) is broke so I get to test the Heath warrantee :)

You can save some cash by getting a remote PMD kit on ebay. Saves some coin for sure. Or just carry a backup PMD.

I have both the Pennsecola Diesel and Heath Kits. Heath has a better mount. Pennsecola has a better extension harness cable.

Keep us posted on Hubbies progress ;)
 
okay what is the difference between and fsd and pmd? just where it is mounted?

A PMD is always an FSD, but an FSD is not always a PMD. I hope that clears it up for you J...

FSD = Fuel Solenoid Driver
PMD = Pump Mounted Driver or, in other words, an FSD that is mounted to the injection pump.
 
Okay so the truck will be running just find and will stall out of no where it will it usually recranks and runs but occassionally you will put the key in and it won't make a sound. The glow plug light won't come on and it is quiet.

1. Does the engine crank, or 'turn over'? yes when it isn't having a problem, quiet when it is having and"issue"
1a. Does the engine start and run? beautifully when it does turn over


I dont think its the PMD. When its acting up, does your lights, radio and other accessories still work or does everything quit?
 
everything quits, it just as peaceful as can be it just turns itself off... whenw e orginally replace the PMD it did get a bit bucky, but this is a quiet turn off or not start, and when no start lights come on, except wait to start it won't kick on the glow plugs... new symptom, the past couple of days the radio has decided not to work (might not even be conected but I am adding everything I can think of). We have a spare PMD, our orignal replacement, it "Failed" shortly after we bought it, so we bought another, well come to find out it didn't have the little resistor on it. So the question now is can we take the resit. off the possible bad PMD and put it on the spare to swap them out? Hubby wants to cruise with the bad one, wait for it to buggar up and then swap to see if it corrects the problem... at least he's not blue booking it any more... he is still wondering about the computer under the glove box, has anyone had theirs to go out and if so symptoms? thanks you all! still trucking for now!
 
To get the resistor out of the old FSD/PMD you need to tak a paper clip and open it up, bend it in half and bend little hooks on the ends. Then you can hook on to both sides of the resistor and pull it out of the module, you may need to use pliers or vise grip to pull with. It takes a bit of effort, but just work it back and forth and it will come eventually. A dental pick may work as well.

It doesn't sound like a PMD problem your currently having. I think you should look more to the battery connections or the ignition switch. When the ignition switch goes hinky, it prevents power from going to anything that needs to be on during start ie. glows, starter etc. Look more towards that situation. Relocating the PMD is important, but unlikely to be causing the total power outage.
 
I think you should look more to the battery connections or the ignition switch.

:iagree:
When everything just shuts off the ignition switch would be my first suspect... You did get hubby to remove, clean, replace ALL the grounds and battery connections didn't you? Always do the Free Stuff first :smile5:

Oh - BTW - YOU could probably do the grounds and batteries... You might seriously consider wearing gloves though - Could get messy :queasy:
 
This is likely a bad connection at the main battery feed.

Try this, when the beast balks and there is nothing, using a Volt meter, test the voltage at the main feed lug on the junction box under the hood.

The 96 should see this box on the LH side inner fender well.

The main feed comes from the LH battery + cable and is usually part of the Plus cable on that side. The main feed should be a number 4 cable.

The cables corode under the jacket and it can't be seen.

If the negative cable on the LH battery goes sour then the circuit will not complete and things will not work either.

Both ground cables and the positive cables are suspect.

Bolt type terminals with heavy cables and soldered eyes are prefered to the side terminals used by the factory.

When you get a no go, have someone hold the key in the crank position while the helper OR??? wiggles the cables and connections.

The issue of the no power needs to be rectified before worrying about the PMD.
The PMD has no bearing on the no lights and no crank.
A bad PMD will stop the engine from running but it will still crank and the glow system will still work fine.

Good luck and keep us posted

MGW
 
okay thank you all, I have new info... here is what has happened this evening, on the way to wally world the truck bucks and the "service throttle light comes on, engines seises and once reving good light goes off. after a long grocery shopping with the kids at wally world we get all packed up go to crank it up and the beast's "Wait to start" light won't come on. SO Jason (said hubby) jumps out and replaces the PMD, nothing. hubby jumps out and takes battery cables off, both negatives, wait for ever (cold, kids asking billions of ???) reconnect truck cranks. We get half a mile away and truck turns off (stalls) (here is where I need to add a correction) the engine goes off but some dash lights are on. pull over and try to crank up again, "wait to start light" flickers and cranks briefly then turns off again. Hubby swaps PMD nothing, wait several minutes engine cranks put in drive and it quits. Hubby decides maybe something with "drive" cranks it and puts in 3rd it runs fine (this could be just a flook, who knows at this point). We noticed during one of the "stalls" the battery icon comes on and the check engine light is on. Then the air bag light began to flash 7 times before crank and 6 times after crank (I don't know maybe the truck is sending me an SOS, but I wrote everything down to pick all your brains). Hubby had a long week but we're leaving him along to bond with the truck tomorrow to do clean the grounds, something with the wires under the steering wheel and a few of the other suggestions, I noticed him eyeing the sale lot at the nissan dealership on the way home... ANy other suggestions? will update after tomorrows bonding session... radioman, thank you for the confidence but I go cross eyed when tools and engines come out, I do the research and spend hours on the internet looking at parts for us to replace and he figures the rest out! good night to all...
 
Sounds like my Ign switch scenario... next time its not displaying its lights and no-start condition, cycle the key back and forth ALOT and see if one of the times it makes that contact to verify ign switch replacement.

I had to do mine 2 years ago, and truck had 85k on it then, so it is defanately an item that only gets 10 years or so of use out of it. If you do replace it, replace with a Delco unit. You get what you pay for there.

I can even remember a distinct light pattern, and beilve it also only displayed the Service Throttle light (no wait to start) on key onw/out the final powercontact that ign switch wasn't making that atttempt.
 
Sounds like my Ign switch scenario... next time its not displaying its lights and no-start condition, cycle the key back and forth ALOT and see if one of the times it makes that contact to verify ign switch replacement.

I had to do mine 2 years ago, and truck had 85k on it then, so it is defanately an item that only gets 10 years or so of use out of it. If you do replace it, replace with a Delco unit. You get what you pay for there.

I can even remember a distinct light pattern, and beilve it also only displayed the Service Throttle light (no wait to start) on key onw/out the final powercontact that ign switch wasn't making that atttempt.

:iagree::iagree::iagree::iagree:
 
hello, to all thank you for your past help, it has been a whirl wind of holidays and such. We have actually neglected the beast for awhile, but have been back under the hood so to speak recently. we began thinking the person who posted about cycling the key "ALOT" was on to something and were about to buy that new part. We had been driving it and when we had problems that seemed to remedy it. but... when I went to crank the beast I got nothing, I did have dash lights so I began cycling the key "ALOT" and with each cycle a different combo of lights and such would come on, sometimes the annoying bell would ring letting me know I had the key in the cylinder and sometimes not, but after over 50 cycles the wait to start light would not come on. I unplugged the box behind the glove box, waited, nothing. I then noticed something odd, a new symptom, something under the cd player and behind the plastic paneling was making some R2D2 noises. I took the key out and it still made the weird R2D2 noises. I got out (now being pregnant I am not really happy at this moment and was not even calling the truck the beast) I disconnected the positive cable off both batteries and let it sit in the yard, I was tempted to make "for free" sign. My hubby came home hooked everything up and guess what... it cranked... I have day next week I will be kid free and as much as my hubby doubts it I am planning on trying to do something to this truck... I have a deadline before I will have to do something so my family and new baby can all ride together... What ideas do you have??? what would make that noise? Something frying? Could it be the culprit? Help please... thanks -J
 
Never cycle the key ON-OFF-ON "a lot" - the PCM is an Intel-based microprocessor controlled computer, just like your PC, with some AMD stuff in there, also - imagine how your PC would react to that scenario, banging the power on-off-on, and the resulting state of functionality - knowing that that is the usual result of frustrated ownership, it is highly unusual that people don't have any more unexplained electronic failures than is reported, here

The reported symptoms equate to ignition switch deterioration, as well as other possible failures - first step towards resolution is reliable switching function - faulty connections, whether in connectors, terminations, or switches, gives same symptoms as faulty active devices, such as sensors, controls, and electronic modules

That '96 Sub is rather long in the tooth, here in '09, and that switch has operated many thousands of cycles per year - need the ignition section of the switch to make good electrical connection to the ESO and FS and FSD\PMD on the Inj Pump, Lift Pump, Glow Plug Controller, and PCM B4 you can proceed with any other required troubleshooting

Pristine power and grounding connections are equally as important, and being much cheaper to fix, should be addressed first

Battery capacity ranks right up there in importance, and since cold weather bleeds mature (read: aged) battery power, easy to check, expensive to replace, still needs to be done, if you've required one winter jump already
 
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