1989 4 Cyl Manual To 5.0 With 1993 5.0 Manual Donor Car

mark32

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Nov 15, 2015
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Hi,

So I have a 1989 4 cylinder notchback manual that I will be converting to a 5.0 using a 1993 5.0 manual donor car. My question is what is the best way to tackle down the wiring with this situation. I know that 89 and 93 mustangs have very different wiring diagrams and pcms. Also since they are both manual would I need to swap the pedals or anything is either one stronger? And also do any of the mechanical parts such as the k member, brake master cylinder, cross member need to be swapped? Also i do like the 1993 steering wheel better how hard would it be to move that over ?Any other help regarding this is much appreciated. Thanks!
 
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90sickfox

I didn't really have an issue with the stink...
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The pedals are the same.

You will need to swap the dash harness ( or whole dash ) into the 89. The steering column can be swapped too...that way you keep the steering wheel.

The wiring is different between the two. The easiest way to tackle this is to swap the 93 harnesses into the 89. There are also differences with the column, gauge cluster, and gauge surround. The addition of an airbag changed the harnesses for the dash and the front harness...drivers side shock tower.

If you located a v8 engine harness for an 88 or 89 then you could leave the dash alone. That would be the simplest way. You could literally put the engine and bell housing in....plug up the injector harness...route the engine harness ( through passenger firewall ....hook up connectors....plug in v8 computer... And do burnouts :nice: till you blow the 4cylinder rear....you need that, too. Brake line swap.

The fuel lines need to be swapped. The tank and pump are the same.
 

Boostedpimp

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May 8, 2003
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You literally have to move all wiring over from the 93 to 89 since they are different years.. the ideal situation would be to have the donor car be the same year otherwise you'll have to source out what harness for what you'll need because they all don't play nice together unless you want to do some serious pin moving.


87-89 everything will work with each other. The main harness and dash harness will connect via two gray & black connectors by driver side strut tower

90 will work with just 90 because it was the first year with airbags so the pin out changed. These connect via the same gray & black connectors as previous years but will also have a white connector as well which is the airbag system

91-92 (early) airbag system and pin out changed.. as well as the fact that this year harness uses a single round reddish brown connector instead of the previous years two gray/black ones. 91/early 92 also has the fuel pump relay to sit under the driver's seat.

Late model year 92 and 93 are the same and will connect to each other. It'll have the fuel pump relay on the engine side just below where the maf would be mounted. It will also have just a single round reddish brown connector for connection to the dash.

4 banger Head light harness needs to be swapped or just extend the alternator wires so they reach

Injector harness something changed in 91 so 87-90 are compatible while 91-93 are compatible

There is also the oxygen sensor which is important. If you use the wrong one it'll fry the ecm basically there are 87-90 auto, 87-90 manual, 91-93 auto and a 91-93 harness.

Manual transmission harness I believe it's 87-89 and 90-93 compatibility wise

besides that there's a bunch small stuff you need to change off hand I can name a few which are

throttle cable (four banger's are too short so you'll need the v8 one)
cruise control cables same deal as above
Fuel Lines which run from the filter up to the pas side frame you'll need because four bangers run to other side of car
Intermediate Brake line, the one which runs from the rear up to the front because it'll interfere with the exhaust or just bend out of the way
Exhaust hangers for dual exhaust
MAP/BAP sensor are different from four to eight cylinders
Tach in the cluster is different and will a thousand rpm's off if not swapped


You won't have to touch the peddles, k member, suspension, brakes, booster, crossmember etc to get it going.
 
Last edited:

mark32

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Nov 15, 2015
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Thanks for the input guys. I guess the best thing too do is to swap the entire harness. I will be swapping the suspension and rear end and all that too. Does anyone have any diagrams on the entire wiring on the 93 5.0 foxbody?
 

General karthief

wonder how much it would cost to ship you a pair
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Theres more to it than just swapping the harness as was explained in the first couple posts, it's a large undertaking but not impossible. And worthwhile if done right.
Here is a link to some wiring diagrams, not everything, you may look into getting a assembly manual for the 93 model year to help with the swap.
http://veryuseful.com/
 

mark32

Member
Nov 15, 2015
38
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The pedals are the same.

You will need to swap the dash harness ( or whole dash ) into the 89. The steering column can be swapped too...that way you keep the steering wheel.

The wiring is different between the two. The easiest way to tackle this is to swap the 93 harnesses into the 89. There are also differences with the column, gauge cluster, and gauge surround. The addition of an airbag changed the harnesses for the dash and the front harness...drivers side shock tower.

If you located a v8 engine harness for an 88 or 89 then you could leave the dash alone. That would be the simplest way. You could literally put the engine and bell housing in....plug up the injector harness...route the engine harness ( through passenger firewall ....hook up connectors....plug in v8 computer... And do burnouts :nice: till you blow the 4cylinder rear....you need that, too. Brake line swap.

The fuel lines need to be swapped. The tank and pump are the same.
Hey, so if I use the 89 5.0 harness can I still use the 93 computer or do I have to get the a9l? anything else I have to do? I don't really want to swap the whole dash over its pretty overwhelming.
 

90sickfox

I didn't really have an issue with the stink...
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The 93 computer will work with a 89 harness.
 

mark32

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Nov 15, 2015
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Okay guys I've tried to take out the 93 dash harness out but could not go through with it as it was very overwhelming I have located a 89 maf harness that I'll be using with the a3m PCM. So can I use the 93 injector harness and o2 sensor harnesses with the 89 harness? I know that earlier someone said they changed something so its not compatible but I just want to make sure.
 

Boostedpimp

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