85lebaront2 Posted February 14, 2022 Share Posted February 14, 2022 Big Blue has a complete new 1996 system, with new tanks, new FDM's, new lines, etc. So, there shouldn't be a problem - right? I didn't remember you had done that, should be no issues then. Darth's is 1990, which is still pretty much the same. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 14, 2022 Author Share Posted February 14, 2022 Big Blue has a complete new 1996 system, with new tanks, new FDM's, new lines, etc. So, there shouldn't be a problem - right? As for what I did today, I took the engine harness apart and took out some of the systems I'm not using, like EGR, and then installed it. As of now the injectors, TPS, IAC, ECT, & oil pressure and coolant temp for the gauges are now all connected - as far as the engine harness goes. I'll still have to connect the oil pressure and coolant temp for the gauges through the main harness and then to the gauges. I think I'll use a spare C325 connector to do that. However, I left the misfire sensor wiring in the harness, but don't have the sensor nor the connector. So I'm just going to coil it up and secure it near the front of the engine. And I don't have the connector to the A/C compressor. While I'll still be using the '85 system to control it the computer wants to know when it comes in or cuts out, apparently to adjust the idle, so I have some wiring to do there as well. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 14, 2022 Author Share Posted February 14, 2022 I didn't remember you had done that, should be no issues then. Darth's is 1990, which is still pretty much the same. Yep, it is all new. As is most of the EFI stuff. Should work quite well. Link to comment Share on other sites More sharing options...
85lebaront2 Posted February 15, 2022 Share Posted February 15, 2022 As for what I did today, I took the engine harness apart and took out some of the systems I'm not using, like EGR, and then installed it. As of now the injectors, TPS, IAC, ECT, & oil pressure and coolant temp for the gauges are now all connected - as far as the engine harness goes. I'll still have to connect the oil pressure and coolant temp for the gauges through the main harness and then to the gauges. I think I'll use a spare C325 connector to do that. However, I left the misfire sensor wiring in the harness, but don't have the sensor nor the connector. So I'm just going to coil it up and secure it near the front of the engine. And I don't have the connector to the A/C compressor. While I'll still be using the '85 system to control it the computer wants to know when it comes in or cuts out, apparently to adjust the idle, so I have some wiring to do there as well. On the misfire detector, good luck, I have been trying to find the trigger for Darth, it is part of the counterweight at the front of the engine, then the timing cover is different to hold the sensor. Only used on OBD-II CA spec under 14000 gvwr trucks. Apparently about as common as hen's teeth. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 15, 2022 Author Share Posted February 15, 2022 On the misfire detector, good luck, I have been trying to find the trigger for Darth, it is part of the counterweight at the front of the engine, then the timing cover is different to hold the sensor. Only used on OBD-II CA spec under 14000 gvwr trucks. Apparently about as common as hen's teeth. I won't hold my breath, and IIRC it is turned off in the EEC. But I thought I'd leave the wiring in place, just in case. However, Darth runs fine w/o it, so I'm not too worried about not having it. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 15, 2022 Author Share Posted February 15, 2022 I won't hold my breath, and IIRC it is turned off in the EEC. But I thought I'd leave the wiring in place, just in case. However, Darth runs fine w/o it, so I'm not too worried about not having it. Bill - I need some help. I think I've figured out all of the wires and connectors I have "hanging out" save for this one. There is only one Red/Yellow wire in it and it goes into C101 and therefore out into the engine harness. I can't figure out what it is. Any ideas? Link to comment Share on other sites More sharing options...
85lebaront2 Posted February 15, 2022 Share Posted February 15, 2022 Bill - I need some help. I think I've figured out all of the wires and connectors I have "hanging out" save for this one. There is only one Red/Yellow wire in it and it goes into C101 and therefore out into the engine harness. I can't figure out what it is. Any ideas? AC cycling pressure switch, the one in the picture is probably C106 and the wire should be long enough to go from C101 to the HVAC wiring on the other side of the truck. On the 85 it would have been the wire running along the suction hose to the compressor. It goes from a plug near the HVAC system and connects to the output side of the cycling pressure switch. Looks like it is BK/Y H on the 1985 and it went directly to the compressor clutch coil in 1985. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 15, 2022 Author Share Posted February 15, 2022 AC cycling pressure switch, the one in the picture is probably C106 and the wire should be long enough to go from C101 to the HVAC wiring on the other side of the truck. On the 85 it would have been the wire running along the suction hose to the compressor. It goes from a plug near the HVAC system and connects to the output side of the cycling pressure switch. Looks like it is BK/Y H on the 1985 and it went directly to the compressor clutch coil in 1985. Perfect! Thanks! It is C106, and it does go through C101 to the high pressure cutout switch and then to the clutch. But, since I'm running the 85's system I don't need this bit as the 85 will control the compressor. I'll just need to tie the DG/O that's sticking out of the engine harness to the clutch circuit so the ECU knows when the compressor comes in. But, having just looked at the wires sticking out of the harness, in addition to the DG/O and R/Y there's a black and gray/white. I'll have to figure out what those are at some point. Link to comment Share on other sites More sharing options...
85lebaront2 Posted February 15, 2022 Share Posted February 15, 2022 Perfect! Thanks! It is C106, and it does go through C101 to the high pressure cutout switch and then to the clutch. But, since I'm running the 85's system I don't need this bit as the 85 will control the compressor. I'll just need to tie the DG/O that's sticking out of the engine harness to the clutch circuit so the ECU knows when the compressor comes in. But, having just looked at the wires sticking out of the harness, in addition to the DG/O and R/Y there's a black and gray/white. I'll have to figure out what those are at some point. I would use it the way the 1996 wiring is, because the engine harness all comes through C101 so if for any reason the intake has to come off, it's one simple disconnect for everything. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 15, 2022 Author Share Posted February 15, 2022 I would use it the way the 1996 wiring is, because the engine harness all comes through C101 so if for any reason the intake has to come off, it's one simple disconnect for everything. Then I'd have to rewire something that is already working. If the intake has to come off the A/C compressor can stay on. So if I just use a male/female 1/4" connector to join the 96's DG/O compressor sense wire to the 85 compressor control's BK/Y then I can easily pull the engine harness. However, I just spotted the statement in the 85 EVTM that the 8500 lb and up trucks didn't get the snubber diode. Doubt the ECU would be very happy about that, so I'll have to add one. Link to comment Share on other sites More sharing options...
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