AndrewFrias

Just jumped in the truck, no AC again, no OD, im thinking im testing this alternatir wrong... Or i grounded out the alt. Ehen i was testing it which caused everuthing to work properly... For a few minutes. Just through the fluke on it and VAC was fluctuating between .050 and .057. I'm ground the on the fluke at the battery and put in the positive lead on the black wire that's leading to the alternator is this correct?

Weird, i have fluctuating vac at the alt. And battery ground... 0.040 to 0.050 up n down n up n down... Also, AC IS BACK, haven't driven it yet however, im thinking that the bottom bolt of the alt wasnt solid, causing a terrible ground, and power flying throughout the circut!!! What the heck! Seems like AC noise was confusing the PCM, could this be from the loose bolt? if my vac is fluctuating is that bad? I gotta pull some cattle from Hamakua side to Hilo, wanna do it sunday!!!

So, every darn Auto Store had a different AC reading on my alt. FOUND A FLUKE AT WORK, gonna check it out!

Smokes, thats the main ground! Perhaps I should try this....

So, took the same Alternator to an alternator shop and they said the ripple is .1 and .0... The dude at the Alt. shop sed the alternator is CHERRY. He also said that the tester at NAPA adds to the VAC, therefore increasing the NAPA reading to .9. He also added that there were no bad diodes....

So 0.9 vac is ok? I took it to oreillys after and they came up with Ripple... .39 damn. Cant believe how difficult this electric stuff is.

Guys, took my alternator in to Napa, AC was 0.9 but their tester said it was good!!!! WHAT GIVES? is that even possible? 0.9!? Guys, took my alternator in to Napa, AC was 0.9 but their tester said it was good!!!! WHAT GIVES? is that even possible? 0.9!?

5. Check for poor connection/terminal contact at APPS harness connector. Repair as necessary. Ensure APPS connector is still disconnected. Start engine. Using a DVOM, measure voltage between cylinder block (ground) and terminal No. 3 (Light Blue/Black wire) on APPS connector. If the voltage is greater than 5.5 volts, go to next step. If the voltage is 5.5 volts or less, go to step 8. Voltage is at like 0 on the connector at this wire, i stuck a paper clip in to try and pull the voltage up, and the truck began to rev... i will attach a picture of the scanner

Gonna take on that diagnostic in the morning. Meanwhile, pulled the codes with my scanner, it sed no engine dtcs however, it did say Transmission DTC present P0123.... So what computer is this pulling from!? The key trick says the same thing

Yep, nothing. To be quite honest, the 4th gear hunting was occuring until I died out and never got it back. Is it possible that the APPS just needs to be changed? I donʻt suppose I have dead pedal, the truck is rather smooth throughout acceleration, and it doesnʻt ever hiccup, it just wont shift into OD now...

gonna go through the P0123 code diagnostic... Damnit, wish there was a plug and play fix...

Nothing really, checked the grounds, wire brushed the terminals and ground areas, and cleared them... some dielectric grease to suppress any noise, and cleared the codes...

So, went for a short drive, and only the P0123 code comes up on the dash....and I still have no OD.... Im thinking APPS? Otherwise everything feels smooth and tight!!!!

UPDATE: -Tried to check for AC noise, but apparently I do not have the correct DVM to do so. Both batteries are steady 12.7 12.8 cold, and get in the 14ʻs, whilst truck is running. Now down to the nitty gritty. Pulled codes and a **** load came up... Key trick produces: P1693-Companion DTC from ECM and PCM P0123-High Input at TPS Scanner pulled these: P1689-No Communication between ECM and IP P0122-Low input at the TPS P1698-CCD from TCM P0122(AGAIN)- Low input at the TPS Damnnnnnn!!!! Where do I start? Should I ERASE the codes and try to drive the truck? This is the first time I have done something to this extent... Im pretty versed in mechanics, however, this electric stuff blows my mind. Thanks guys!

UPDATE: Truck has no fkn OD now, and AC is not working. AC compressor is not turning on, and I tried switching the relays to kick it on... nothing. gonna try and pull the codes tomorrow!

Ok, so, I changed the Fuel Filter, lift pump, and bled the system. IT RUNS NOW... could it possibly have been a plugged filter in combination with a bad lift pump? There are still codes, however I havenʻt had the right scanner to pull it from the truck. On the ODO it will only pull P0123 & P01639.... But starts and RUNS FINE for now...

Yea, Drip, like 3/4 tank, put 10 gallons in and the gauge is past the 3/4 mark... Ill let you guys know what I find out!

I forgot to add, that yesterday, the RPMs werenʻt showing as I cranked it. Today, with the pump priming, the RPMs were showing and the Wait to start light came on every turn of the key... WTF

Thank you! Gonna try this. Will let you know! Wait, is it possible to try this without it starting?!

The ground that goes behind the alternator to the gray clip was relocated to the front, heard it was doing the jumping TC thing, since i've had it, nothing went wrong until this... so Iʻm assuming AC noise was a struggle. I'll check on the codes, how do you check for AC noise?

Ok so, I did replace the pump with another block mounted pump, and Iʻm assuming i wasnʻt getting 12v to the lift pump, because THIS MORNING, I went down to my truck, turned the key and the pump was priming. Although it was priming, it still did not start. I did not check if there was fuel at the IP, but im gonna try and drain the filter and housing and change filter... I have been checking the codes through the dash, iʻm certain theres more... Is it possible that my ECM is fried? OH YEA, AND FOR A WEEK, MY TRUCK HAS BEEN HAVING A DIFFICULT TIME SHIFTING INTO OD!!!!

Year of truck: 2000Motor: 5.9 CumminsMods: None...However, I just had the AC guy evacuate and refill the AC to his spec. How is the truck primarily used: Just used to go to work, however, i recently purchased the truck from a guy that wasnʻt using it much. Seems like it was sitting for quite sometime. When did the issue start, and if it's intermittent or all the time: The truck turned off last week thursday, and restarted easily. On friday(7/22) i parked it on a hill(running) and it died. I rolled it down and on the side of my house and now it wonʻt start. It throws a P0123 and P1639 code and wont start for sh!t. I can hear the Lift Pump priming, and hit the schrader valve on the IP to see what the pressure looks like -it kinda trickles out. Havenʻt yet checked fuel pressure, but will do it asap. Also, I tried to reset the APPS because thats what iʻve been told the P0123 code is, but nothing. No start, lots of crank. While I tried to start, I cracked the lines at 1 and 3 and no fuel is coming out of there...Darn truck sent no warning signs or hiccups. Has been running strong until it went Kaput! So, today, I checked the truck out, cycled the key, and the lift pump cycled. Replaced the lift pump, and now... NO CYCLE! When I was replacing the lift pump, I noticed the fuel line was rather dry. The in and out lines both leaked no fuel which is rather odd, given the last time I replaced a lift pump, I lost some fuel. I am dumbfounded that the cycling is not happening... Thank you all in advance for your help... Aloha, Andrew