73 electrical gremlin
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Great synopsis of the troubleshooting process!
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Snowmach, I have had similar problems in the past. For what its worth more often than not electrical problems are mainly due to a poor ground at some point in the wiring. Sounds like you have checked the engine compartment pretty well and sonds like you have found a lead in the fuse box. So here goes I would pull the fuse box again and make sure the bolt that mounts it has no corrosion and were the bolt goes into the body that it is clean as well. Then while the box is down and (accesable ) as you know they are not the easiest to get to I would pull all fuses by some electricle contact cleaner and use either emery paper , sand paper or a good small wire brush ( like the ones used to clean radiators,ect youre part store should have one ) they have a small head about 1" long. Spray cleaner and scrub vigorously until all contacts are bright and shiny. Now take brush and clean mounting surface were fuse box mounts,now look at the back of the fuse box were the wires go into it and make their connections and look at those for any signs of corrosion, now mount box and take a test light and check for power on one side of were the fuse clips into its mount. You should have power on all fuse spaces on one side or the other of them. If you have power install fuses and give it a try. Sorry I should have mentioned earlier also to disconect battery while cleaning. If at this point you still have no power go back and clean battery posts AND battery terminals if you have not done so. Then if still no power you can make up a ground and run a couple new ones to see if it helps to the body and engine block. You can use 14 guage wire and crimp on terminals, this is just a test to see if it helps. Remember any rust or corrosion of any kind under any ground can be the culprit.Worst case if you find your harness , fuse box ect are indeed junk let me know I have a harness complete with fuse box ect that I took out of a mach that was wrecked badly. I had to actualy cut the harness in two places to get it out of the twisted mess, but would be easilly put back together and is in great shape otherwise. Also if you see any junk blue butt connectors in your wiring cut them out and solder the connection then heat shrink shut. Those damn things cause more problems and corrode easier than any connection Ive seen. Hope this helps. Let me know how it goes
YLWHRSE
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One last thing to use anything that makes hole in the wiring at any time can and will leave a hole in the wiring no matter how small it is . This is how moisture get,s into the wiring alot of times and short out . Auto parts stores do carry a white greese to help with the electrical connections to keep them from shorting out . Even in the light bulb plugins C.L.
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Thanks everybody for the great support and advice! Sorry I haven't been on the last few days, but it's been a busy week. I'm hoping to get back in the garage this weekend to continue working on the Mach. Its not looking to good though since the wife will be out of town and I'll be home with the three kiddos! But on another note, there's a new pony in the corral! I just bought a new 2011 Mustang GT! (Black) I plan to push the Mach out of the garage tomorrow and take some pictures of both. I'll post ASAP!
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Congrats on the 2011 GT; it's hard to only own one Mustang!
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Congradulations on the new addition.
Wow, looking forward to the obligatory pictures!
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Congrats on the GT! Just don't get so wound up and in LOOOVVE with the new one you forget about the Mach1! JTS 71 Mach1
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While I'm in love with the GT, I will always have my "love/hate" relationship with my Mach! This past weekend came and went without me stepping foot in the garage, but this coming weekend is looking good. So hopefully I'll be able to get the Mach out and take some pictures with the GT. (and troubleshoot)
As for my electrical problem, I didn’t mention that I eventually pulled the dash cover and gauges out to get better access. I got a (somewhat) better look at the plug and the main wire just looks way to burnt to reuse safely. I'm not an electrician but it makes me nervous to just try and "fix" it. Especially when I really don't know why it's shorting in the first place. So I'm thinking that a wire harness is probably the safer answer. The current wire harness has too many wires clipped and I think I'm getting grounds from it somewhere.
I've been scouring craigslist and ebay looking for a (reasonably priced) wiring harness from a 71-73 stang. Mostly what I'm finding is the under dash harness which has the fuse box included and spreads throughout the inside of the car. What I think I need is the harness/feed that plugs INTO the fuse box and goes through the firewall to the engine bay. (Is there a name for this harness?) What I've seen so far doesn't seem to be what I would need….or is it? I can’t tell for sure from the pictures that I’ve seen on ebay. I’m not set on buying a harness just yet, but want another option before I start snipping wires. If anybody has any info or leads on the wiring harness I would need, I’d really appreciate it.
Also, here’s one picture of the ’11 GT. She’s darn quick right out of the box and such a thrill to drive!
Regards! SWOMACH1
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AIN"T SHE PRETTY! The harness as I know it, is simply called the underhood harness. There may be an official name but I've never heard it or seen it? Mac's catalog calls it, firewall to headlight wiring and it only goes to 1968. I can't seem to find my others catalogs at this moment. But I'm sure it's listed in them also, but it may be hard to get one for a 71-73, as there seems to be an invisible break there. My advice would be to go New, as that will eliminate a lot of unforseen problems such as dry and cracking insulation, inside wrapped sections where you can't see. Which could be where you original problem may be hiding! Just a thought. It may be pricey, but you'd know what you got!
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So here it is now August and I'm finally getting back out to the garage to work on the Mach. I took another hard look at the plug and tried to reinstall it again. Well, to make a long story short I noticed that a tab on the side of the plug was broken and had bent in a way where the plug wasn't fully seating. So I ground it off with my rotary tool and reinstalled it. Everything works perfectly now in regards to the ignition. So thats the good news, the bad news is that she doesn't want to start. She's turning over, but just not firing. I've installed a couple harnesses and fixed a couple of wires, seem to have continuity but i'm going to have to scour through the engine compartment to see if I'm missing something. What are some recommended ways to check for spark? I have a test light and an analog multimeter. Thanks and sorry its been awhile since my last post.
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