Thanks, I need a set of those. I got some alligator clips with wires last Amazon order, I'll get those probes when I buy the TPS. I figure it has to be that since I've eliminated the wiring and likely the PCM since there is no MAP code.
From what I have read about the 4L80, I must have left in a checkball I was supposed to remove or vice-versa. Another possibility is the reverse band being worn, but I think it was replaced with a new part. I recall testing the actuator hole with a screwdriver. The internals were put together to book specs, so I'm thinking it has to be something related to the valve body- which was a pro rebuilt unit itself since I was unable to take my old one apart. Either way it will be a pain since I have to drain all of the new fluid I put in to pull the pan.
I tried one other thing, and I'm glad I did. I pulled the wire connector from the side of the trans and it then went into reverse. It still wants to stall in drive though. Apparently there is a circuit in these that if it detects forward motion via the shaft sensor locks out reverse. Now I just have to figure out what is miswired. Shouldn't take more than a year or two.
Just a brief update- I was able to move the truck from one garage bay to the other! I noticed the fan belt is running too far forward on the AC compressor, so I'll have to space it out maybe 1/4". The shift indicator is also off by one position. As far as the wiring goes, I think the issue is the 4L80 segment swap for the PCM didn't work as planned. I plan to go through the trans wiring and then reflash a stock 5.3/4L60 tune. I know there is a way to rewire the harness to use a 4L80 with a 4L60 truck.
This project is on hold for a couple of weeks while I rebuild the engine in Mrs. Al's SUV. The GMT360 platform is really poorly designed for maintenance work as compared to the Durango.
The Durango is semi-sidelined while I make other involved repairs to other vehicles. In the meantime, while on parts hold for the new projects I have been upgrading the old Android radio to a newer one with a larger screen, more memory, and a faster processor. The radio fits a Toyota Corolla and required some modification to the dash opening. I have gotten all of the wiring sorted out (the new radio had no diagram or password for settings), but then the 21 year old radio controls on the steering wheel came apart. JB Weld to the rescue! I found a set from a later model Durango that look the same so I'll give them a try. I looked at the wiring for a 2004 Durango and as far as the switches go it is the same. The newer buttons have 3 per side vs the 2 right and 3 left from the 1999 wheel I bought. Apparently the later models use the bus sytem to communicate with the radio. Since I'm programming my own key functions that is irrelevant. All they need to do is fit in the wheel and plug into the wiring.
I also measured the belt and it looks like a spacer of .188" or 3/16 should align the compressor properly. I've ordered another piece of aluminum (and a new belt) and will make a rear bracket for it.
I'm not sure what the deal is with the transmission. I had to move the truck again, so I plugged in the connector and it went into reverse after fiddling with the shifter some between R and N. The fluid level looked good, so this will be some more work to do once the belt situation is corrected and I can run the engine for a longer period of time. I also have to put the front bumper back on and attach the inner fenders.
One other problem that has popped up is the speedometer is pegged at 120! I think that happened once I corrected the PCM connector wiring and the dash got communication restored. I'm hoping it is just stuck there and if I take it apart and free it then it will straighten out. I still need to work on the tach adapter as well, but the other gauges are working OK. Finally on the dash I need to pull the trans temp bulb since it is on constantly. The good news is no check engine light. I replaced the throttle position sensor but still need to scan the GM side of things.
Here it is 10 months later and I was able to spend some time on the Durango again, even though all I did was move it outside. The good news is the speedometer reset and began operating properly after I drove the truck up and down the driveway. The bad news is the adjustable thermostat housing is leaking and I shredded another fan belt. The tach is still not working. Oh, and it needs another $150 Group 27 battery.
I looked over the belt drive and I think I didn't get the alternator aligned well enough. To fix this, I'm going to try an ICT Billet Corvette high mount bracket. They make 2 different brackets, one is $160 and mimics the OEM bracket (places the alternator too far over), the other one is $130 and places it slightly higher but closer to the center of the engine. They give dimensions for everything, and I measured the bracket I made. Looks like this one will fit OK. They are a good outfit, I have used several of their parts on an engine rebuild I did this year.
For the coolant leak, I got another lower hose and plan to reuse the OEM housing and make 1 hose out of 2 by cutting it in the middle.
The tach remains a mystery. I did some more reading and read about a Cummins tach adapter for Ford trucks. For the 1998 models, the wiring looks similar, but the adapter is over $300 and doesn't have the proper 8 PPR output needed for this tach. I need to double check my wiring on the eBay adapter since it should work. I double checked the service manual, and as far as I know the tach operates only off the crank sensor, not the cam sensor or both.