Dean_L Posted July 10, 2020 Share Posted July 10, 2020 After an unfortunate fire this year, I have been putting my 85 F250 (7.5L) back together. I pulled a harness from another 85 F250, but I can not figure where this part of the harness plugs into. My truck has a build date of Sept 84 and the donor vehicle was Nov 84, so they should be the same Link to comment Share on other sites More sharing options...
FuzzFace2 Posted July 11, 2020 Share Posted July 11, 2020 Maybe not Sept if early could be 84 as this is when new models came out/ Nov would be a 85model year. I have a 11/80 that makes it an 81 year truck as the wiring I have looked up also matches it. What color are the wires and from what month truck? Dave ---- Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 11, 2020 Share Posted July 11, 2020 Maybe not Sept if early could be 84 as this is when new models came out/ Nov would be a 85model year. I have a 11/80 that makes it an 81 year truck as the wiring I have looked up also matches it. What color are the wires and from what month truck? Dave ---- Yes, give us the wire colors. Or, better yet, you may be able to figure it out. Go to Documentation/Electrical/Standard Wire & Color Codes. That document gives the color codes and circuits Ford used. Download the one that has been OCR'd and search for the wire colors, making sure to use the proper abbreviations shown at the first of the document. Link to comment Share on other sites More sharing options...
Dean_L Posted July 17, 2020 Author Share Posted July 17, 2020 Yes, give us the wire colors. Or, better yet, you may be able to figure it out. Go to Documentation/Electrical/Standard Wire & Color Codes. That document gives the color codes and circuits Ford used. Download the one that has been OCR'd and search for the wire colors, making sure to use the proper abbreviations shown at the first of the document. The two single wire connectors are Red with White dash, maybe red with yell dash. Hard to tell The two prong connector has two red with white (or yell) dash wires and one brown with white (or Yell) dash. looking at the OCRD, I could not find red with white dash, but red with white stripe is temp gauge to temp sending unit. I have the single wire temp sending unit in the manifold so this could not be it. Are there other temp sending units besides the one at the manifold? For brown with white strip, it could be "thermostat switch feed" but I cant find this on the 1985 Wiring diagram or in my 190-1989 Truck Parts Master Catalog for 7.5L Thoughts?? I traced the wires, here is an image of where they go into the firewall Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 17, 2020 Share Posted July 17, 2020 The two single wire connectors are Red with White dash, maybe red with yell dash. Hard to tell The two prong connector has two red with white (or yell) dash wires and one brown with white (or Yell) dash. looking at the OCRD, I could not find red with white dash, but red with white stripe is temp gauge to temp sending unit. I have the single wire temp sending unit in the manifold so this could not be it. Are there other temp sending units besides the one at the manifold? For brown with white strip, it could be "thermostat switch feed" but I cant find this on the 1985 Wiring diagram or in my 190-1989 Truck Parts Master Catalog for 7.5L Thoughts?? I traced the wires, here is an image of where they go into the firewall Does your truck have the "hot fuel handling package" If so that is likely part of it. Be sure you have the correct diagram if you do, Ford changed it 3 times I think between 1984 and 1986. Link to comment Share on other sites More sharing options...
Dean_L Posted July 17, 2020 Author Share Posted July 17, 2020 Does your truck have the "hot fuel handling package" If so that is likely part of it. Be sure you have the correct diagram if you do, Ford changed it 3 times I think between 1984 and 1986. Im using the diagram that is posted for 1985 here. I cant find another diagram. I do suspect there are variances from the early model Sept-Nov 84 built 85's compared to the late model 85's. I feel I must have had this on the truck before the fire. As you can see from the photos, this is plugged into a harness coming from the firewall. I just dont see where it should have gone. I should have paid a little closer attention when I got the harness from the donor vehicle. Im not sure if I have the 'hot fuel handling package' in 25yrs of owning this truck I have not come across this. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 17, 2020 Share Posted July 17, 2020 The two single wire connectors are Red with White dash, maybe red with yell dash. Hard to tell The two prong connector has two red with white (or yell) dash wires and one brown with white (or Yell) dash. looking at the OCRD, I could not find red with white dash, but red with white stripe is temp gauge to temp sending unit. I have the single wire temp sending unit in the manifold so this could not be it. Are there other temp sending units besides the one at the manifold? For brown with white strip, it could be "thermostat switch feed" but I cant find this on the 1985 Wiring diagram or in my 190-1989 Truck Parts Master Catalog for 7.5L Thoughts?? I traced the wires, here is an image of where they go into the firewall I'm confused as to what the actual question is. But let me see if I can help. Your sig doesn't say, but I'm guessing that you have dual tanks if you have a 460. If so, I think the diagram you want is the one below, although I don't know what an OCRD is, this one is from the 1985 EVTM. Note that connector C325 has a red/yellow hash wire in it, and if you go on down a page or two it says it is near the ignition module. But also note that there's a red/yellow hash wire going off to Page 52. And here's Pg 52, which also shows several other connectors with red/yellow hash wires that are applicable to the 7.5L. Are you trying to figure out which connector that is? Or do you have a problem? Link to comment Share on other sites More sharing options...
Dean_L Posted July 17, 2020 Author Share Posted July 17, 2020 I'm confused as to what the actual question is. But let me see if I can help. Your sig doesn't say, but I'm guessing that you have dual tanks if you have a 460. If so, I think the diagram you want is the one below, although I don't know what an OCRD is, this one is from the 1985 EVTM. Note that connector C325 has a red/yellow hash wire in it, and if you go on down a page or two it says it is near the ignition module. But also note that there's a red/yellow hash wire going off to Page 52. And here's Pg 52, which also shows several other connectors with red/yellow hash wires that are applicable to the 7.5L. Are you trying to figure out which connector that is? Or do you have a problem? Thanks Gary, Im trying to find what the connector goes to. Memories fade, since I replaced my intake and carb with an Edelbrock 20 years ago, Im guessing I just wither cut off or left these disconnected on my wiring harness. Looks like the red/yell hash and tan/white plug goes to the decel throttle kicker and the two red/yel hash coming off that wiring goes to the fuel vent solenoids. I dont have any of these on my truck anymore. So Ill just leave be for now. Thanks Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 17, 2020 Share Posted July 17, 2020 Thanks Gary, Im trying to find what the connector goes to. Memories fade, since I replaced my intake and carb with an Edelbrock 20 years ago, Im guessing I just wither cut off or left these disconnected on my wiring harness. Looks like the red/yell hash and tan/white plug goes to the decel throttle kicker and the two red/yel hash coming off that wiring goes to the fuel vent solenoids. I dont have any of these on my truck anymore. So Ill just leave be for now. Thanks Not sure I'd cut them off just yet. Wait until you get everything going and then make the call. But what are you powering the electric choke with, assuming you have one? One of the red/yellow wires is better than some approaches. The better approach is the get the same wire but after it has passed through the oil pressure switch. That way your choke only runs if the engine is running. Link to comment Share on other sites More sharing options...
Dean_L Posted July 28, 2020 Author Share Posted July 28, 2020 Not sure I'd cut them off just yet. Wait until you get everything going and then make the call. But what are you powering the electric choke with, assuming you have one? One of the red/yellow wires is better than some approaches. The better approach is the get the same wire but after it has passed through the oil pressure switch. That way your choke only runs if the engine is running. Ill keep it in tack for now. Good idea for the electric choke. When I swapped to the Edelbrock Performer Series carb 20 years ago I went with a Manual choke. I found it started alot easier when I could manually control the choke. Link to comment Share on other sites More sharing options...
Recommended Posts