Greetings from a guy who needs help with a foxbody.

thefonztm · Mar 21, 2026

Dunno what else to say here. Point me to good foxbody threads.

I just did the heater core and I'm having a weeeeee bit o' trouble getting the dash back in. Harness tape has rotted and the attachment sites are all failed. Have new tape and plenty of zip ties. Need a good image to reference how the harness is supposed to sit.

I have some more questions including a chunk cut out of the harness... I'm not too worried about it. Must have been cut by a previous owner and I drove it that way for years. But still...

I'm gonna spend today redoing the tape and marking where the wire clip things used to be.

Video of the harness and such including the cut portion.

View: https://www.youtube.com/watch?v=D09EBx58EpM

Might need to be realistic about getting away from this car. sooo. Total shot video

View: https://www.youtube.com/watch?v=hQr7EAVO3cE

Mcmahst · Mar 21, 2026

I would suggest you purchased the Ford electrical vacuum troubleshooting manual (EVTM) for your model year Mustang. It’s one of the best sources for wiring and contains many illustrations. That’ll probably help you put the wires back where they belong.

thefonztm · Mar 21, 2026

Thanks for the direction. I went a head and acquired one for the $20. It'll undoubtably be helpful all over the car. But in this particular case, it's not giving me the image I hoped for.

I'm looking for one that shows where the harness attaches to the firewall. The best I can find in the guide is showing the harness and the dash. Not useless, but not as useful as hoped. I could still really use an image showing where on the firewall the harness is expected to hang from.

KRUISR · Mar 21, 2026

I could be wrong (it has been 30+ years since I last pulled a dash and frame back), but I would expect most of the wiring to attach to the dash frame, not the firewall. That is how I would interpret the diagram you included.

Mcmahst · Mar 21, 2026

Yes, even on 73 Mustangs, most of dash wiring is attached to the dash, not the firewall. I guess you’ll have to hope someone doing a restoration has pics of the reinstall of the dash. Good luck.

thefonztm · Mar 21, 2026

Well oof. I followed LMR's guide on the heater core change and they did not separate the dash cover from the dash frame. Just pulled the whole dash & reinserted the whole dash.

https://www.youtube.com/results?search_query=lmr+heater+core

I guess the best course of action is to see if I can find a full length dash reinstall video. Might have to figure out how to separate the dash cover from the frame.... Oi....

Noobz347 · Mar 21, 2026

I think if you start fitting it up in there that a lot of it will become obvious.

Make sure you have a healthy supply of quality zip ties in various sizes and a few good pairs of side cutters.

Don't forget to work your vent routing in there as you're stowing wire bundles.

I did this job once in a barracks parking lot when I was at a training school many years ago. Dyed the whole interior. IT was time consuming but not rocket science. Be sure to tag any questionable wiring along the way with some small dayglow zip-ties. Identifying all the grounds can be a pain if they were all disconnected but it's not tough if you're familiar with how to use a multi-meter.

Also... Can't stress this enough. Look for full color wiring diagrams on Ebay for your make and model. I picked up several sets for different years. They're all laminated 11x14.

DadLife0724 · Mar 21, 2026

Diagrams seem pretty accurate? I found them 11x17 laminated, but for $34 bucks it better be good.

LILCBRA · Mar 21, 2026

Just pulled the dash from my 87 a couple months ago. There was a small bundle that was attached along the top side near the windshield. I wasn't really keeping close track of where everything was either, I've had the dash out of my II, all of the wiring in that turned out to be pretty self explanatory, I expect the GT to be about the same. But there are a pic or 2 more that may help on my vert thread if you wanted to browse around there, but this is right after I removed the dash. You can see the wires that I'm talking about here, but they are not part of the dash harness.

LILCBRA said:
Dash is out.

Pulled the harness from the engine compartment to keep it all in the dash. After pulling the liner and disconnecting the washer bottle, I took a closer look at the frame rail area. It doesn't look too bad from this side, only time will tell about the engine side.

Found some more wiring issues as well. These will be addressed while it's out.

I'm out of town atm but should be home tomorrow afternoon. I believe my harness is still snaked through my dash. Im pretty sure I didn't completely remove it, so it should still be there.... I'll try to remember to doublecheck and share if I left it like that.

Noobz347 · Mar 21, 2026

DadLife0724 said:
Diagrams seem pretty accurate? I found them 11x17 laminated, but for $34 bucks it better be good.

You may be right about the size. I have a post around here somewhere with images of mine but they are here:

11 x 17 COLOR Wiring Diagram for Ford 1990 Mustang (Fox Body) US Spec 7 pgs | eBay

Make & Model: Ford Mustang (Fox Body Style). YOU WILL GET A DIAGRAM - NO MATTER WHAT. Prospero's Wiring Diagrams presents 11 x 17 - Bigger than other wiring diagrams. The Quick and Dirty on Our Wiring Diagrams.

www.ebay.com

Just search for the year you're after.

Also: They split up the years on those diagrams. They're not all molded together with tiny little notes that say, "this year only" in the fine print.

thefonztm · Mar 22, 2026

LILCBRA said:
Just pulled the dash from my 87 a couple months ago. There was a small bundle that was attached along the top side near the windshield. I wasn't really keeping close track of where everything was either, I've had the dash out of my II, all of the wiring in that turned out to be pretty self explanatory, I expect the GT to be about the same. But there are a pic or 2 more that may help on my vert thread if you wanted to browse around there, but this is right after I removed the dash. You can see the wires that I'm talking about here, but they are not part of the dash harness.

I'm out of town atm but should be home tomorrow afternoon. I believe my harness is still snaked through my dash. Im pretty sure I didn't completely remove it, so it should still be there.... I'll try to remember to doublecheck and share if I left it like that.

Oh . now I think I see my colossal up. You can keep the bulk of the harness still attached to the dash?

I have a 5 foot snake I'm trying to thread back through the dash. All the attachments to the dash had failed so I thought that was how it was supposed to come out...

I think I've killed the car beyond my ability to do anything...

And oh joy I'm double ****. I just brought it out of storage to try and reinstall this dash after the lot was re painted, now they want us to move our cars again to clean the gutters... Sigh. Life hasn't been what I'd hoped and I **** up with a live that's required me to move oh say 5 times but I really thought I'd be able to hang onto the old foxbody... Thought I was finally gonna get it back in order.

Sunk cost is sunk cost. Time to GTFO and send this car to the graveyard?

If anyone in FL is looking for a project....

LILCBRA · Mar 22, 2026

The harness is still attached to my dash. You could probably reinstall it and throw it back together, I wouldn't think it would take more than an hour or so to do, which would only be an extra hour added to what you have going on. I mean we all f*** up, unfortunately it's the best teacher.

Anyway, here's a quick pic of the backside of mine for some reference.

thefonztm · Mar 22, 2026

LILCBRA said:
The harness is still attached to my dash. You could probably reinstall it and throw it back together, I wouldn't think it would take more than an hour or so to do, which would only be an extra hour added to what you have going on. I mean we all f*** up, unfortunately it's the best teacher.

Anyway, here's a quick pic of the backside of mine for some reference.

Took a quick look before I lose light. I don't see how I'm supposed to get that disconnected. My bundle seems to go straight into the fire wall.

View: https://youtube.com/shorts/pMAB-betW6o

If I can get it out I'll try to get it re attached to the dash. I just don't see a clip to undo. Can I get a look at the drivers side of the bundle from the side?

LILCBRA · Mar 22, 2026

There are a few connections in the engine bay, then the harness runs through a large grommet through the firewall.

LILCBRA · Mar 22, 2026

That section of the harness runs between the brake booster and the fenderwell. I have a few things sticking out of it to keep them out of my way while I work in the car, but here's the location:

LILCBRA · Mar 22, 2026

Oh, and this is the size of the diagrams that @Noobz347 is talking about. I've not really used them yet, but they are pretty damned nice additions to your tool arsenal.

Noobz347 · Mar 22, 2026

Look how pretty they are.

The first set I bought was for my 86. I liked them so much that I bought a set for 89 and a set for 91-93.

Trace a line with a grease pencil across multiple pages... They work great.

Greetings from a guy who needs help with a foxbody.

thefonztm

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Mcmahst

thefonztm

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KRUISR

Mcmahst

thefonztm

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Noobz347

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DadLife0724

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LILCBRA

I wish I didn't have all of these balls in the air

Noobz347

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11 x 17 COLOR Wiring Diagram for Ford 1990 Mustang (Fox Body) US Spec 7 pgs | eBay

thefonztm

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LILCBRA

I wish I didn't have all of these balls in the air

thefonztm

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LILCBRA

I wish I didn't have all of these balls in the air

LILCBRA

I wish I didn't have all of these balls in the air

LILCBRA

I wish I didn't have all of these balls in the air

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

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