marked23

I'm replacing this wire: The wire is a shielded twisted-pair with a drain (SAE J1939/11). The wire seen here is the stock wire. It's comically unkempt. Note that the orange wire is about five inches too long, so that it must be doubled-back to make it the proper length. Also, the shielding is missing from the first six inches, and the last four inches. Neither of these is a problem from a functionality standpoint. I mean, it probably doesn't hurt anything. It's just sloppy. That loose twist of shielding provides no benefit, so why did they leave it loose like that? This is what I made to replace it. All new wire and connectors. It was hard to find a short length of J1939 wire. I found a few sources that were happy to sell me a 250ft spool, but I wasn't happy enough to buy it. I found a guy on ebay selling teflon/silver shielded twisted pair. $35 bought me 25ft. I wasn't trying to get silver. In fact, I wouldn't have bought it if I had realized that this is what it was. However, this is remarkable wire, so I'm going to give it a try. It's temperature rated to 200ºC. I don't know if it's oil rated.

I'm replacing this wire: The wire is a shielded twisted-pair with a drain (SAE J1939/11). The wire seen here is the stock wire. It's comically unkempt. Note that the orange wire is about five inches too long, so that it must be doubled-back to make it the proper length. Also, the shielding is missing from the first six inches, and the last four inches. Neither of these is a problem from a functionality standpoint. I mean, it probably doesn't hurt anything. It's just sloppy. That loose twist of shielding provides no benefit, so why did they leave it loose like that? This is what I made to replace it. All new wire and connectors. It was hard to find a short length of J1939 wire. I found a few sources that were happy to sell me a 250ft spool, but I wasn't happy enough to buy it. I found a guy on ebay selling teflon/silver shielded twisted pair. $35 bought me 25ft. I wasn't trying to get silver. In fact, I wouldn't have bought it if I had realized that this is what it was. However, this is remarkable wire, so I'm going to give it a try. It's temperature rated to 200ºC. I don't know if it's oil rated.

@GSP7 I've chewed up my existing connector doing a bunch of tests to diagnose my VP44. I cut the Pin-5 wire too. So I got this to repair the damage I did. I'll replace all the contacts, while I'm at it.

I found a source for VP44 connectors, and pigtails. http://americadiesel.us/ $13.20 for the connector shell $2.20 for each pigtail (I ordered 10, to allow for a few mistakes) $57 shipping My total was $92. Even with International Priority FedEx fees, that's still cheaper than other sources. It's a genuine AMP 965734, new. Our stock connector has two holes blocked. This one has all nine holes open, so I'll have to plug two. It did not come with the wire-cover back-plate. I ordered 10 pigtails. I was expecting them to be all one color, but I was happy to see that they randomized the colors for me. They aren't the factory colors/stripes, but any color is better than all-the-same.

I found some AMP documents that show the terminal and part numbers. I pieced together the relevant bits. The 929974-x is for 17ga to 20ga wire. The 929975-x is for 13ga to 17ga wire. The heavier gauge is used for power +/- (pins 6 + 7). The rest are all the lighter gauge. I kind-of expect that the stock part was -3, but you'll never find any to buy. -8 seems to be the only gold variant that is available. -1 CuNiSi pre tin -2 CuNiSi silver plated -3 CuNiSi gold plated -4 CuFe2 pre tin -5 CuFe2 silver plated -6 CuFe2 gold plated -7 CuNiSi silver plated -8 CuNiSi gold plated <<< Choose this one. As seen here: Master Electronics 929974-8 Master Electronics 929975-8

@Bobalos, Is that tool used from the front, also? I tried to make one to extract the pins in that kind of connector. I couldn't figure it out. I'm looking for a source of the terminals for the VP44. I found some that have pigtails, but I want to do my own crimps, to avoid butt connectors. Those look close, but they don't have the big stop-flange at the back.

Maybe you've followed the VP44 diagnostics instructions over at blue chip... there's a point where one of the steps involves cutting the wire for pin 5. If you really need to do that experiment, don't cut your wire. Pull the terminal. I made a tool to extract terminals from a VP44 connector. It's just a bit of brass tubing. I put it in a drill and sanded it down until it was small enough to fit into the front of the connector. You need to move the little red tabs. This releases the lock that holds the terminals. But it's not the only lock. Insert the brass tube over the front of the terminal. It should go in about 1/4" or so. The tube will cover the barbs in the terminal... releasing the second lock. Then pull out the terminal. . Good times.

I wasn't really meaning to endorse those diagnostics instructions. I was just using that as an excuse to talk about one of the reasons you might want to extract pins from a VP44 connector. Nevertheless, here it is: https://www.bluechipdiesel.com/vp44_diagnostics.html I cut my pin-5 wire, and I wish I hadn't. It didn't do me any good. So knowing how to extract a pin might save somebody some grief.

Maybe you've followed the VP44 diagnostics instructions over at blue chip... there's a point where one of the steps involves cutting the wire for pin 5. If you really need to do that experiment, don't cut your wire. Pull the terminal. I made a tool to extract terminals from a VP44 connector. It's just a bit of brass tubing. I put it in a drill and sanded it down until it was small enough to fit into the front of the connector. You need to move the little red tabs. This releases the lock that holds the terminals. But it's not the only lock. Insert the brass tube over the front of the terminal. It should go in about 1/4" or so. The tube will cover the barbs in the terminal... releasing the second lock. Then pull out the terminal. . Good times.

It's a 2001 2500 chassis truck. My wife's brother is the original owner. The dealer moved the lift pump from the engine bay, into the tank. That's the only thing I know of that isn't 'factory'.

I know the previous owner didn't do this. He's the kind of guy that would buy a $300 crimper to do one crimp. So that means it came this way from the factory, or the dealer did this. My guess is that the dealer damaged the connector while removing the stock lift pump. This is the connector for the manifold air pressure sensor. Does anyone have an idea what kind of problem this would cause? I mean, if the truck runs, but doesn't have this sensor data, what would the truck do?

I'm going to unwrap and repair my engine wire harness. I figured that I should document what it is, so that I can put it back together when I'm done. This is an image I stitched together after taking about 20 separate pictures. Full_Stitch_6_5600x1000.zip

I contacted Cummins to see about a replacement ECM. They have them for $2700. The 3946242RX part number also goes by ENCORE CM551A. But then I also see a 3942860RX (CM550) that also claims to work with a VP44 for $1500. And also a 3944124RX for $1300. But these other two, I have no compatibility info on. I love how the overnight shipping for a 5 lb. part is $250.

I've done the P1689 troubleshooting steps. I made it to the end of step #8. According to the steps, that means my ECM is bad. In keeping with the idea that "it's probably not the ECM," I've been trying to double-check the communication between the ECM and the VP44. I tried to put an oscilloscope on the VP44 today, to see if I could see the data. If I see the ECM's data, then it's the VP44 computer, not the ECM. I saw something that looked like PCM data, but I couldn't figure out how to set a stable trigger on it. I put channel #1 on the black & white wires (Pins 1 & 2), and put channel #2 on the green wire (Pin 8). Then I tried to trigger off of channel #2. If I tuned the trigger just right, it would hold-still for a couple seconds. I was expecting that the green wire (sync signal) would provide a perfect trigger. Does anyone know the correct scope setup to see this signal?

I'm running Raspbian (RasPBX) on a Pi 3 as a FreePBX server. My wife works with phone systems and needed something to practice FreePBX on.