TrevD Posted March 2 Share Posted March 2 Time for my first question! My 84 is quite the electrical nightmare. It came back to me with an Edelbrock carb and a gm style HEI distributor. The crazy engine harness and brain box were in the bed of the truck and I've deduced that I need absolutely none of that mess, (Likely for sale if anyone needs it). Also, the original body wiring harness was supposedly bad so anouther harness was put in the truck from an unknown parts truck and additional parts of harnesses were in the bed of the truck. I'm stubborn and i want to get this puzzle figured out even if it takes a few months off of my life expectancy!! I've already got the distributor, oil, and coolant temp wires located and spliced into their correct locations. Truck starts with the key and runs good, which is a huge step from the alligator clips and screwdriver condition it was in last week! I'm pretty sure that the body and chassis harnesses don't match due to some of the connectors not matching. I printed off the 1985 wiring harness and have strained my eyes for hours and it's helped a ton, but there are a few plug-ins that I just can't find. Guessing because my truck is an 84 🤪 So for me to attempt to figure out as much of this as I can without blowing up this forum, or paying one of y'all to come visit... Are the wiring colors fairly consistent for all of the years of our bullnose trucks?? A good example would be the body to chassis plugs on the driverside fender apron. The light plug matches and fits. BUT, the second chassis plug which includes the fuel Guage wire is a 4 plug with 2 used pins, while the body plug is an 8 plug with all 8 used. Not sure what the extra wires go to except maybe to the dual tank solenoid?? I assume it's safe to say that the similar colored wires (black and yellow if I remember correctly) could be connected and complete the chassis/body connection? Knowing if the wire colors are consistent would greatly help when I can't match the plugs either on the papers or on the truck. I apologize that I made y'all read so much into that, I'll try to make my next correspondence a bit shorter!!! 😆 Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 2 Share Posted March 2 Help me help you. I have NO idea where you are.. My rear axle in in a zillion pieces. But I can read a schematic, and know these trucks. Show some pictures of your questions. Make it big enough that I recognize exactly what you mean. Link to comment Share on other sites More sharing options...
BigBrother-84 Posted March 2 Share Posted March 2 Are the wiring colors fairly consistent for all of the years of our bullnose trucks?? I have a 84 too. And I use the 85 wiring diagram, it matches. As Jim suggested, you should go step by step and send a picture of each part of harness or connector you are trying to elucidate. One by one would be great and more easy for helping you. Pretty sure that people here can help you to untangle this spaghetti. Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 2 Share Posted March 2 The wire colors are VERY consistent. In fact, if you go to Documentation/Electrical/Standard Wire & Color Codes you'll see the colors, circuit numbers, and applications. There is a minor glitch in the 1985/86 timeframe. The 1986 EVTM states that for that year and after the dots and hash marks previously used in addition to stripes changed over to all stripes. But it didn't happen on the stroke of midnight on December 31st. Big Blue, an 85 with a build date of May 85, has some of the striped wire harnesses that supposedly should have been hashed. As for staring at wiring diagrams, don't. Use the EVTMS. They break things down into systems and lay out the wiring for that system on one or two pages. Plus they have notes as to where components are located and how to troubleshoot the system. Link to comment Share on other sites More sharing options...
ratdude747 Posted March 2 Share Posted March 2 The wire colors are VERY consistent. In fact, if you go to Documentation/Electrical/Standard Wire & Color Codes you'll see the colors, circuit numbers, and applications. There is a minor glitch in the 1985/86 timeframe. The 1986 EVTM states that for that year and after the dots and hash marks previously used in addition to stripes changed over to all stripes. But it didn't happen on the stroke of midnight on December 31st. Big Blue, an 85 with a build date of May 85, has some of the striped wire harnesses that supposedly should have been hashed. As for staring at wiring diagrams, don't. Use the EVTMS. They break things down into systems and lay out the wiring for that system on one or two pages. Plus they have notes as to where components are located and how to troubleshoot the system. I'll note that on my 1984 (build date of 12/1983 in Oakville, ON, also a 300) I've also found striped wiring along with dotted wiring. But never mixed in the same harness. Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 2 Share Posted March 2 I'll note that on my 1984 (build date of 12/1983 in Oakville, ON, also a 300) I've also found striped wiring along with dotted wiring. But never mixed in the same harness. Prior to the change they used stripes, hash marks, and dots, and the EVTM shows which wires should have what. But Big Blue has stripped wires where they should be hashed or dotted according to the 85 EVTM. It isn't a problem and the wiring colors are the same, but you just have to realize that the book isn't exactly right for every truck on all those details. Link to comment Share on other sites More sharing options...
TrevD Posted March 2 Author Share Posted March 2 Are the wiring colors fairly consistent for all of the years of our bullnose trucks?? I have a 84 too. And I use the 85 wiring diagram, it matches. As Jim suggested, you should go step by step and send a picture of each part of harness or connector you are trying to elucidate. One by one would be great and more easy for helping you. Pretty sure that people here can help you to untangle this spaghetti. Ok, I understand. One by one on individual topics or just on this topic? I don't want to get in trouble for loading up the main page 🤣 Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 2 Share Posted March 2 Ok, I understand. One by one on individual topics or just on this topic? I don't want to get in trouble for loading up the main page 🤣 If this topic is "electrical confusion and mayhem," then post all your electrical problems here. Link to comment Share on other sites More sharing options...
TrevD Posted March 2 Author Share Posted March 2 Help me help you. I have NO idea where you are.. My rear axle in in a zillion pieces. But I can read a schematic, and know these trucks. Show some pictures of your questions. Make it big enough that I recognize exactly what you mean. Ok, I'm going to try my best to load up some pictures. I do want to start off saying that I don't know if the truck originally had duel tanks. I haven't found the pictures my dad took of it when he drug it home, but it had duel tanks when he was done. the duel tanks were ran off of a toggle switch on the dash. that and the chassis harness doesn't appear to support the duel tank setup and i strongly suspect my dad just made it duel tank. The person that got the truck and tore into a couple of years ago put in a dash/body harness out of an unknown ford truck that I'm suspecting had duel tanks. There are extra wires, and the ac control unit that came with the spare parts has the tank switch in it. First, the above plug is currently sticking out of the glovebox but wire memory makes me think it was close to the fuel tank selector, though its the wrong plug... and I cant find this plug shape anywhere. It has a couple wires in common with the next plug situation I have. the above picture are of the body side of the harness under the brake booster, the 2 purple wires are common with the aforementioned plug hanging out of the dash. It also has 2 wires, the small black and small yellow wires in common with the chassis plug that's shown below. I know that the chassis side black and yellow are ground and fuel gage. im sure yall know that already, im just still getting excited every time i figure out where a wire goes Before I cut into it and just splice the black and yellow together, I want to make sure all of my thoughts are correct. If all of the above is true, i would like to keep the option available to add my own extra wires to the back to support the second tank in the future. but since only 1 tank has been replaced and the wiring doesn't match up, i just want to get the current set up to work and be drivable. ill fill in the blanks later! Â Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 2 Share Posted March 2 Ok, I'm going to try my best to load up some pictures. I do want to start off saying that I don't know if the truck originally had duel tanks. I haven't found the pictures my dad took of it when he drug it home, but it had duel tanks when he was done. the duel tanks were ran off of a toggle switch on the dash. that and the chassis harness doesn't appear to support the duel tank setup and i strongly suspect my dad just made it duel tank. The person that got the truck and tore into a couple of years ago put in a dash/body harness out of an unknown ford truck that I'm suspecting had duel tanks. There are extra wires, and the ac control unit that came with the spare parts has the tank switch in it. First, the above plug is currently sticking out of the glovebox but wire memory makes me think it was close to the fuel tank selector, though its the wrong plug... and I cant find this plug shape anywhere. It has a couple wires in common with the next plug situation I have. the above picture are of the body side of the harness under the brake booster, the 2 purple wires are common with the aforementioned plug hanging out of the dash. It also has 2 wires, the small black and small yellow wires in common with the chassis plug that's shown below. I know that the chassis side black and yellow are ground and fuel gage. im sure yall know that already, im just still getting excited every time i figure out where a wire goes Before I cut into it and just splice the black and yellow together, I want to make sure all of my thoughts are correct. If all of the above is true, i would like to keep the option available to add my own extra wires to the back to support the second tank in the future. but since only 1 tank has been replaced and the wiring doesn't match up, i just want to get the current set up to work and be drivable. ill fill in the blanks later! Look here: https://www.garysgaragemahal.com/1985-evtm.html Link to comment Share on other sites More sharing options...
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