I have a '90 LX that I am building.. I had a '89 that was wrecked... Question is, other than the airbags, what can I expect to gain/lose when putting the wiring harness and computer from the '89 into the '90??
are we talking just the engine harness or the entire body harness and everything. if its just the engine harness than nothing really...maybe the low coolant sensor but thats about it. the air bag sensor and wiring should be in the body harness so it should stay intact with the car
You should search for "91 harness" and "90 harness". One of them can't be used in other applications, I just can't remember which one.
I want to say it's 90 though. I grabbed a PCM, harness, and MAP sensor from a 90 GT when I swapped my 88 SD over to mass air. After I got everything installed, the car wouldn't start. So I threw another harness in the car that was out of a 91 GT, and everything worked fine. It has something to do with the airbag system is integrated into the harness in 90, as opposed to being a "stand alone" system in the 91+. So you MIGHT run into problems there. But like I said, search first because I can't remember which year is the problem, the 90 or the 91, and I can't remember which one wouldn't work for me and which one did.
There was no power going to the fuel pump relay with the one harness, but it worked fine with the other. I did some internet searching at that time and found out that one of those two years have a year specific harness, so you can use an 87, 88, 89, 91, 92, and 93 harness in any other Mustang, but 90 can't be used in anything other than a 90.
I am talking about the harness that comes from the computer into the engine bay. All of the other harnesses are in the car... Sounds like I have to have a '90 harness from the computer into the engine bay or I may have fuel pump issues... Next question is where is the best place to get a year specific harness, does Ford still sell them or do I need to try and find a '90 in a junk yard somewhere??? Of course I will search the classifieds here and on the Corral, I suspect it will be difficult to find a harness for a '90 LX... Thanks for the assistance, I will be back with more ?'s as I begin to drop the motor in...
i wrote very good info on exactly this question while back but can't find it... but here's what youre looking at. if you have a 89 harness you going to run into problems. why??? the speedo cluster has different connectors, now you could repin each individual connector and make it work. but that's up to you. second the fuse box is not going to FIT into your dash panel. WHY? because if i recall right the box is shaped diffent. now you could cut up your dash and make it the right shape, but then youre still stuck with the fuse box cover not fitting. the airbag not working is a given. you also have to take into consideration if you car is a stick or auto. there is a clutch saftey switch down by the clutch pedal. if i recall correctly its pink/grn or pink/blu (but check your diagrams) now if it's from an automatic it will loop back into the connector. you can keep this as is, but on a manual if you start it guarantee it will take off in 1st gear while starting (not so good for the gf who doesn't know). if you want to make it work on an auto and the harness is from a manual well then you need to jimmy up a safety switch loop. Or if you have a manual you can unplug the the safety clutch loop and just plug/play into the actual clutch saftey connector. hope this helps
Ok.. I looked at the diagrams and did some more searching and still need a little clarification (bare with me) I understand that there are several harnesses, the only one that is not in the '90 is the harness that is connected to the computer and into the engine bay, is this the ECC harness?? Now, it also sounds like the A9L computer is the same from '87-93, if so, then I am not understanding why I can't use the harness (the specific one I referred to above) from the '89 in the '90?? If the computers are the same and I have all of the other harnesses then why won't it work, I hope this makes sense.. Thanks...
Only a 90 harness will work on a 90. An 89 will not work.
Installed an 89 harness that was supposed to be a 90 harness. Car would not run. Had to rip the whole thing out and start over with a true 90.
Been there done that.
Save yourself a ton of headaches. Get a 90 harness.
I believe the only difference in the engine harnesses are the location of the fuel pump relay. In pre-90 cars the fuel pump relay was inside the vehicle under the driver's seat. In 90 and later cars the fuel pump relay is in the engine compartment. This should be relatively simple to fix. I could have the years wrong though, I don't remember off hand.
Still confused, there are several harnesses in these cars, correct? Everything I have read and everyone is saying use a 90 harness in a 90, Are you speaking of ALL harnesses or specific ones?? The car has the original headlight harness, the car has the original air-bag sensors and the harness connected to them, the car has all original harnesses on the interior (under the dash, etc.) the car has the fuse panel, the only ones that appear to be missing is the one from the computer into the engine bay and the O2 harnesses. Am I missing anything else, do I just need these 2 harnesses from a '90, does Ford still sell them?? I have not been able to find a source that sells them, I just want to understand this harness thing, thanks....