DEAD VP or Electrical? its story time!

SixOhh · Jan 25, 2015

I've never seen or heard of that code. wow!

so the VP stays that cool just from fuel running thru it constantly? i find that kind of hard to believe since the raidant heat from the block/ head are almost 200*

id love more details on this

Mopar1973Man · Jan 26, 2015

Ok. Measure the temperature of your pump body after being ran on 100*F day. I've done it. It barely 140-150*F tops. My laptop gets that hot just typing this message.

So the other fact is all electronics can survive much higher temperature in storage. so as long as the truck isn't running the electronics will withstand the heat. Like I can toss my laptop in the front seat of my truck and let it bake in the 150*F cab temps. It's fine. The laptop will fire up and work just fine when remove from that environment. So with the VP44 as long as thee fuel pressure is 14 or better the fuel is being pump through it and temps fall in a mere few seconds. Just like turning on the cab baked laptop the fan drops thee temps in mere few seconds.

Sorry to say I've got a 2 year degree in Electronics...

SixOhh · Jan 26, 2015

i completely understand. so don't you believe that heat soak is way worse on the electronics when you kill the truck, lets say when running errands on a hot Texas summer day?

Mopar1973Man · Jan 26, 2015

SixOhh · Jan 28, 2015

well her truck is definitely guilty of the 0254 and 1688...

how does one go about testing for AC noise and fixing it?

the truck has one of those ground loop isolators (or a line conditioner?????)on the PCM by the passenger side firewall. we had a hard shift issue after the rebuild on the 47re and it helped..... can these 2 issues be related michael?

Mopar1973Man · Jan 29, 2015

As for th noise filter yank that off... That is for sure sign the alternator is producing AC noise being you had to use noise filter for the PCM to stop TQ Conv lock up issues.

https://www.youtube.com/watch?v=MGaHaIXZioA

Test the AC noise level at the alternator BATT terminal Then if it measures over 0.1 Volts AC you replace the alternator. Make sure to test your new alternator in the store before leaving. I sure do suck to get home with a alternator with the same issue. Even new ones in a boxes can be bad.

Copied post from my side of the fence...

OK! Problem solved! Yippee!!!

Took the recently purchased Alternator back to O'Reilly's where I got it from, had them test it on their tester. They told me they run the test 3 times and if they get a PASS all three times, its a good alternator. When I asked about measuring AC Voltage, they looked dumbfounded, so I asked them if I could hook my multi-meter up to the alternator while they tested? They agreed! So now this alternator is reading .35 Volts AC as the first test PASS'S, they run the second test and we get a FAIL, the guy gives me a funny look, checks his wires and runs the third test and we get another FAIL. So the guy now rells me guess we have a bad alternator but they don't have another one on the shelf and I will need to wait till tomorrow to bring one in from the other store. I say, I'm OK with that, but that I've learned my lesson and we are going to have to test the next alternator as well before I leave the store with it. The next morning (yesterday) they call me and let me know the alternator is in and I can come down and pick it up. We do the test like before, and this time we get a PASS, PASS, PASS, however my multi-meter is reading 0.3 Volts AC, and then I also notice that on their machine there is a box at the top that says Diodes and across from that box on the screen says N/A. So I ask the guy about it and he says their machine has no way of testing the diodes, it only test for overall condition of the alternator. Unhappy with what I'm hearing and looking at, I request my money back which they had no problem with at all, however the core I earlier took in was no longer in the store so the gave me cash in the amount of $215.00 (their core charge on that alternator $36.00 along with the full purchace price of $179.00.)

By this time I have no core, only to find out all the other auto parts stores around town are charging a $70 - $80 core charge for this alterrnator, and a lot of the places have no tester. Starting to get a bit frustrated, I decided to quit messing around and go to the most reliable place in town I know of, a small family owned auto electric and mechanical shop (Auto Electric, Anchorage, Alaska). I was hoping that maybe they had heard of this isuue I am having with the TCL and get fixed up with a good alternator. They rebuild all kinds of auto electrical parts right there in house as well a run a full service auto mechanic shop. Well,,,,I explained my problem to them and showed them a printed copy of the troubleshooting procedure I got from the Mopa1973Man website, to which they said...never heard of this before. However these guys are real pro's and they didn't blow me off. They took my concerns seriously, brought two techs in out of the shop to talk with me about this, as I explainded to them the 0.1 Volt AC upper limit thing. They genuinly got concerned and were pulling down alternators, checking them on the bench and checking outputs at vehicles in the shop. In all, I was in there for about two hours while they tested and discussed and in the end the shop found me a NEW alternator and gave me a heck of a deal @ $239.00 w/no core charge. The NEW alternator was putting out 0.22 Volts AC on their alternator bench vise, and that concerned me cause I was looking for something under 0.1 VAC. However in further discussion, the techs I was working with concluded, (and BTW they turned out to be right), that the test machine itself was putting off AC Noise and that the Fluke Meter was picking up that AC Noise during the test, and that since the Voltage Regulator is on either the PCM or ECM, the only way to accuratly read out the AC output on this alternator was to put it on the vehicle and measure it at that time. So,,,I took the alternator home, hooked it all up, and WALLA... measured at the battries -0.01 Volts AC @idle, and 0.00 Volts AC @2000 RPM. Feeling pretty good at this point I take it for a test drive. Runs and shifts perfectly. NO MORE PROBLEMS!!!

Cory, I believe he's the manger or maybe owner, at Auto Electric said though he's heard and dealt with a lot of Dodge Cummins issues like this before, had never heard of this shifting problem being linked to + 0.10 VAC output on the alternator. He asked me to check back in with him to let him know how all this worked out. I will do that on Monday, as well as express my thanks for all the personal attention, efforts and concerns Auto Electric gave to me to adress my problem.

In the meantime, my utmost gratitude to Mopar1973Man for sharing your knoweledge and wisdom on this issue. I had tried all the bandaid tricks only to have them each work for anywhere to a couple hours to a couple days or so and then reappear. I believe what was happening was that as I fixed a ground or foiled a wire, it masked the problem just long enough for the diodes on the alternator to get a little worse and then BOOM, the problem is back!

Very good information Mopar1973Man!!!

Happy Holidays!!!

SixOhh · Jan 29, 2015

wow, this is all new to me but the proof is in the pudding!

this makes sense on so many levels. her truck has been shifting like crap and at the same time her remote start/turbo timer started doing strange things.

i know what im doing when i get home after the new VP pump is installed.....

thanks for opening my eyes on the situation sir!

Mopar1973Man · Jan 30, 2015

Not a problem.

DEAD VP or Electrical? its story time!

SixOhh

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SixOhh

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SixOhh

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SixOhh

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