Foxbody Wiring Harness Question
10-25-2017, 10:21 AM
#1
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Join Date: Apr 2017
Location: Nebraska
Posts: 24
Foxbody Wiring Harness Question
Okay so I have a 1989 ford mustang LX that was originally a 2.3l. I am in the midst of a swap to the 302, and I went into the project without much info because I saw a sick deal that was a steal. The engine is out of an 86 ford Thunderbird and so is the wiring harness. The tranny (currently rebuilding) is out of god knows what, the guy was guessing a truck but its an AOD. I understand that there is a lot of part swapping involved all around the car but I am focusing on the wiring harness. the wiring harness I have isn't going to work so I found another for an 89 mustang 5.0l, but it doesn't come with the ECM or the MAP sensor. can I use the ECM and MAP sensor off of the 86 harness and put them on the 89 harness? Thanks!
10-25-2017, 01:18 PM
#2
The first thing you should be aware of is the 302 out of a 86-88 Thunderbird is a standard output 302,not the HO 302 like comes in the 86-93 Mustangs.It puts out 150hp compared to the Mustangs 225hp.This engine can be converted to HO specs by replacing the heads,cam,injectors,etc with parts from a 87-93 Mustang or aftermarket parts.The standard output 302 also uses a different firing order than the HO 302.
SO= 1 5 4 2 6 3 7 8
HO= 1 3 7 2 6 5 4 8
If you run the SO 302 in the 86,youll have to use the wiring harness and ecu that matches the SO 302,because of the firing order and camshaft differences.The 86-88 Mustangs and 86-88 Thunderbirds are both SD(speed density)SEFI systems,so the Thunderbirds fuel lines,fuel rails and fpr can be used.The fuel lines that run from the tank to the fuel rails are on the wrong side of the car on a 2.3 Mustang,so you'll have to get V8 fuel lines in order to run a SO 302 or HO 302.Theyre on the passenger side for a 302.
If you run a wiring harness and ecu from a 89 5.0 Mustang,the SO 302 will not run.The following link details alot of info about the differences between these two engines.Ive gotta search for another link Ive got,but it goes into great detail about the harnesses and which ones work with which year cars.I'll edit this post with that link as soon as I locate it.
http://www.coolcats.net/modifying/ho_conversion.html#fi
The answer is no,to your question about the 89 5.0 harness working with the 86 SO 302 and its ecu and map sensor.The 89 5.0 harness has to be used with a maf ecu like the A9L,A9P,A3M,etc.It also has to be used on a HO 302 with the 13726548 firing order and camshaft.The SO 302 has the wrong firing order and camshaft for the maf ecu.The 86-88 Thunderbird SO 302 is SD(speed density) like the 86-88 Mustang is,but it has a different firing order(15426378) Now,if you take the Thunderbird shortblock,swap the cam for an HOcam(13726548)
and add the 87-93 heads,intake,injectors,etc,the 89 5.0 ecu could be used.
***EDIT***
I located the link I was referring to above.The author of this link doesnt want his info copied/pasted,for whatever reason,so Im dropping you a PM with the link so youll have access to it.So check your inbox for the link.
SO= 1 5 4 2 6 3 7 8
HO= 1 3 7 2 6 5 4 8
If you run the SO 302 in the 86,youll have to use the wiring harness and ecu that matches the SO 302,because of the firing order and camshaft differences.The 86-88 Mustangs and 86-88 Thunderbirds are both SD(speed density)SEFI systems,so the Thunderbirds fuel lines,fuel rails and fpr can be used.The fuel lines that run from the tank to the fuel rails are on the wrong side of the car on a 2.3 Mustang,so you'll have to get V8 fuel lines in order to run a SO 302 or HO 302.Theyre on the passenger side for a 302.
If you run a wiring harness and ecu from a 89 5.0 Mustang,the SO 302 will not run.The following link details alot of info about the differences between these two engines.Ive gotta search for another link Ive got,but it goes into great detail about the harnesses and which ones work with which year cars.I'll edit this post with that link as soon as I locate it.
http://www.coolcats.net/modifying/ho_conversion.html#fi
The answer is no,to your question about the 89 5.0 harness working with the 86 SO 302 and its ecu and map sensor.The 89 5.0 harness has to be used with a maf ecu like the A9L,A9P,A3M,etc.It also has to be used on a HO 302 with the 13726548 firing order and camshaft.The SO 302 has the wrong firing order and camshaft for the maf ecu.The 86-88 Thunderbird SO 302 is SD(speed density) like the 86-88 Mustang is,but it has a different firing order(15426378) Now,if you take the Thunderbird shortblock,swap the cam for an HOcam(13726548)
and add the 87-93 heads,intake,injectors,etc,the 89 5.0 ecu could be used.
***EDIT***
I located the link I was referring to above.The author of this link doesnt want his info copied/pasted,for whatever reason,so Im dropping you a PM with the link so youll have access to it.So check your inbox for the link.
Last edited by wbrockstar; 10-25-2017 at 02:44 PM.
