Progress Thread Let's try this again...

[Willybill32]

I replaced the starter cable and mounted the brackets in the correct spots, as my old one was dangling.

Speaking of dangling, that’s basically what the wiring harness for my exhaust o2 sensors are doing. Is there a correct way to restrain them?

To remove the negative battery cable, I had to remove the drivers side fender liner and the windshield washer tank to get to the other side of this bolt:

Which looked like this:

That cylindrical thing is loose, I think it was tack welded at some point but I had to use some pliers to keep it from spinning.

After freeing the cables, I found this:

I have no idea what all these wires are for, or why they all converge into one wire. They all go into the fender and back into the interior, so my guess is they’re a ground for some interior electronics? I don’t think they’re supposed to look like that.

The broken terminal goes to a black wire that seems to follow the cluster back into the interior. I’ll have to get a new terminal connector for it. I’ll look some more in my books to see if I can figure out what this is all supposed to look like.

Anyway, that’s my update for this weekend. Car still doesn’t work, but I did get the starter and cable installed so that’s good, I guess.

The ground bolt and “cylindrical thing” look to me like someone added them. I don’t think Ford used that type of “nut”.

It’s always interesting to try to figure out what prior owners tried and how they handled it.

Bill

 

[Noobz347]

It looks kinda like a "Riv-Nut" but I didn't mention it because he said it looked like it was tac-welded. He also said it spun. It would have to be an [old] one. I have not known recent styles to spin. The sheet metal generally tears away first.

 

[85GTStangGuy]

Didn’t the 85’s have the battery on the right?

Yes, they did.

 

[AeroCoupe]

If the car is injected whether SFI or CFI (sorry did not go back through all 27 pages) then they typically have the ECU ground right behind the battery. My 83 T-Bird was CFI and it was behind the battery on the right side and my Coupe is behind the battery on the left side. Almost looks like the stock hole that the self tapping screw wallowed our and someone used a rivet nut of some sort to make it a better connection which appears to have failed as well.

 

[Alldegree]

It looks kinda like a "Riv-Nut" but I didn't mention it because he said it looked like it was tac-welded. He also said it spun. It would have to be an [old] one. I have not known recent styles to spin. The sheet metal generally tears away first.

I just assumed it was tac welded, it does look like a rivet now that you mention it. It spins but doesn’t come out, so I think it was a rivet that came just a bit loose at the sheet metal.

If the car is injected whether SFI or CFI (sorry did not go back through all 27 pages) then they typically have the ECU ground right behind the battery. My 83 T-Bird was CFI and it was behind the battery on the right side and my Coupe is behind the battery on the left side. Almost looks like the stock hole that the self tapping screw wallowed our and someone used a rivet nut of some sort to make it a better connection which appears to have failed as well.

I was thinking it could be the ecu ground as well, because the new battery cable has a connector for that, but the old one doesn’t. I’ll have to crawl under the dash to see where that bundle goes to make sure.

Even if it’s a ground, isn’t it generally unsafe to have multiple wires going into one wire that’s the same size? I’m trying to figure out how I could repair this.

 

[Alldegree]

After some research, I’m pretty confident the big bundle of messed up wires is the EEC ground. I took a look at this thread on allfordmustangs:
https://www.allfordmustangs.com/threads/computer-ground-disconnect.1077561/

And somebody describes a wire just like mine, as in a bundle of tape covered wires that converge into one.

They also mentioned that if you install a 3G alternator or a mini starter, you’re supposed to run a 4 gauge battery wire from the fender apron ground bolt (that I’ve been struggling with) to the negative battery ground on the engine. Is that correct? There was no mention of this in either the alternator instructions or the starter instructions.

 

[89ripper]

Yes. Per jrichker's instructions you need a 4guage ground wire to match 4guage current side....

Thread '3G Alternator Install: A How To'

Jul 3, 2006

Here is what Mr. Alternator (864)591-1066 has. A 130amp alternator complete with stator wire, short bolt, and with no exchange required. Mine came with the standard finish for $145.00 with shipping included. I received it in about four days. As you can see from the picture the new 3G is approximately the same size as the old one. The cooling fan has been moved to the inside.

Required Tools:

--------------------------------------------------------------------------------

The other parts you will need can be bought at...

• Roland69
• Replies: 146
• Forum: Fox 5.0 Mustang Tech

• 

Post 3 and 20

 

[AeroCoupe]

You want the Big 3. Battery ground to chassis (front frame rail is best) and chassis (usually the same spot) to the engine block. Third one is Alternator to Battery and you will need a fuse on this one. I also replaced the battery to the inner fender starter solenoid.

All of this was 4 ga and crimped copper logs with heat shrink. Clean the surface for your ground and use some kind of antioxidant on the connections. I got mine at an electrical supply house.

 

[Alldegree]

You want the Big 3. Battery ground to chassis (front frame rail is best) and chassis (usually the same spot) to the engine block. Third one is Alternator to Battery and you will need a fuse on this one. I also replaced the battery to the inner fender starter solenoid.

All of this was 4 ga and crimped copper logs with heat shrink. Clean the surface for your ground and use some kind of antioxidant on the connections. I got mine at an electrical supply house.

So the factory battery ground on the timing cover won’t work with the alternator? Or is that just a different way of doing it?

I have a heavy gauge cable with a big fuse running from the alternator, but it hooks up to the starter solenoid.

 

[AeroCoupe]

Going to the starter solenoid is fine I just went to the battery as I have the option for side posts and my starter solenoid was getting crowded. I have the ground on my block in a location that is not factory and that is shown here on Post 29:

Post in thread 'electrical smoke when starting'

Mar 16, 2024

Took me a while to find a good picture of what I am referring to and it is not on the timing chain cover. This is not a picture of the motor in either of my cars but this is where the ground wire is connected. This boss is on the stock blocks as well but this is the only picture I could find really quick that showed the location.

• AeroCoupe

 

[Alldegree]

I’m trying to plan on how I would repair the ground wires I found. For the computer ground, could I just cut back the harness to a point where it’s not all dirty and frayed and splice in wires of the same gauge? Should I have them all converge into one wire at the end like it did when I found it?

My new negative battery cable has the female quick-disconnect connector that splits off from the main wire. I think I’ve read somewhere that later cars use that as the computer ground, could I try to find a male one and use that?

 

[Noobz347]

Honestly, I would try to put them back the way that you found them.

Having said that, if you put the wires together like they were when you found them and then change the mount point, it would probably be fine.

Once you start splitting up grounds and planting them in arbitrary locations, you can end up with a ground loop that will drive you nuts with electronic hum that can be difficult to pinpoint.

 

[AeroCoupe]

When that happened we would just remove the ground on the head unit and problem solved. The head unit would ground through the antenna.

 

[Alldegree]

Here’s the list of what I’ve done this weekend:

-replaced frayed and dirty portion of computer ground with proper 10ga wire and ring terminal

-bolted up the new starter and trigger wires to their locations on the starter solenoid
-connected a 4ga wire from the negative ground location on the timing cover to the chassis ground location on the fender apron
-replaced both battery cables

Got in the car, turned the key and…

Nothing.

Same thing happens as before. I do hear a faint pop from what I think is the battery as I turn the key to the accessory position. I’m hoping it’s just arcing a little because the battery terminals are still loose, but I’ll check it out more. I don’t feel any heat or see/smell any smoke coming from anywhere.

I’m going to sniff around with my multimeter and try to figure out where power is going when I turn the key, because it’s clearly not going to the starter.

 

[Alldegree]

Here’s a link to video of what I’m seeing:

 

[Alldegree]

GENTLEMEN, BEHOLD:


Turns out my fan controller problem and no cranking problem was related somehow. A wire from a fuse tap to the rest of the harness came loose from its butt connector, and that little 14GA wire was somehow enough to prevent the motor from cranking.

I don’t know how I wired it into the starting system of the car like that, I’ll have to look at the instructions and some of the wiring diagrams I drew up to try and figure that out. I followed LMR’s video step by step, including the fuses they tapped into.

Anyway, now I can finally get back to my coolant situation and put my car back together, but that will likely be next weekend.

 

[Noobz347]

 

[Alldegree]

Humpty Dumpty is finally back together again:

Putting the final pieces together was harder than just about anything else. Getting the fender liner in was a typically difficult process, but reinstalling the strut tower bar was a special kind of hell. I dropped a nut along with a socket, which disappeared. After looking all over the floor, I figured out that they somehow fell into the fender liner.

After I got that figured out, I started on the wheels. I jacked up the front of the car so I could wedge the wheels on the ramps to tighten the lug nuts.

That’s about when the car fell off the jack.

It fell a few inches onto the stands. The pad slipped forward from under the k member, the hood slammed shut and the whole thing made a pretty loud crash.

After changing my pants and assuring my family I was ok, I checked for damage and have found none so far.

After getting everything back together and driving around the block, the only problem I’m detecting is a slight rev hang and a somewhat strange sound from the exhaust. I’d imagine the rev hang is almost definitely a small vacuum leak, could that be causing the exhaust sound as well? I can only describe it as a kind of breathy whoosh sound. I’ll see if I can upload a video tomorrow.

 

[Monkeybutt2000]

Had to go back to page 1 to see what this car was. Silver 86 GT best looking Fox IMO.

 

[Alldegree]

Had to go back to page 1 to see what this car was. Silver 86 GT best looking Fox IMO.

Thanks! I didn’t think I’d like the silver, but it’s definitely grown on me. It’s the original color, but not the original coat. The guy I bought it from painted it with a more modern clear coat.

The whooshing noise and rev hang have all but disappeared today, so I’m going to chalk it up to reverberations in my garage and the computer having a fit after being unplugged for so long.