Please Help - Shortage In Wiring Harness


New Member
Nov 24, 2015
Please Help - My battery on my 90 mustang lx 2.3l was going bad. I went to jump start it and accidentally put the opposite poles on the battery. Long story short. I caused a shortage in the car. We tested all the wires(a lot of wires we're rigged) on the solenoid and was able to that the yellow wire, which divides up into 5 wires and goes into the wiriring harness has a short. When the key is turned to the on position everything clicks on put once the key is turned to start the engine a loud click happens and everything shuts down. The wire (when connected to the solenoid) also causes the ground to become hot. ANY IDEAS AS TO WHAT PART OF THE HARNESS MAY BE SHORTAGED OUT. I'm sure it's a fuse linkage but it's to dark to go searching now.
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Start by checking all fuses. There's some good wiring diagrams located at this site Mustang FAQ - Wiring & Engine Info I'm guessing you may need the help of someone with some automotive background if youre that green that you connected the battery cables wrong :cool:
I was just extremely tired from martial arts training plus a throbbing headache and when I hooked the jumper cables to the car being used to jump mine I mix matched them. And alright I'll check those out if anything im going t just have to replace the entire harness seeing as how the wiring throughout my car has been rigged by the previous owners. You should see the cluster F*** on the starter solenoid. Lol

Update: those diagrams are for the 5.0 mines athe 2.3
I can scan a diagram tomorrow for you for the 90 (I have one also) is it a Cali car or no? Here's an image I had saved on my photobucket.



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Ok so I've been checking the body wiring diagram to see where this wire breaks off into 4 other wires but it doesn't seem to say. However on the '91 and later diagram it seems to display these wires. I'm just confused as to which wire goes to the ecc, fuel pump, a/c fan, etc...


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Again is it a California car or "dual" plug? If it is then you're in for a heap of trouble... Also you need the engine diagram the one I posted if it's not good enough quality let me know!
Thanks that diagram is clear and I was able to find a Manual in a 91 convertible in a junk yard. So I have both diagrams.
Its not a Cali spec car... took me forever to find out if it was or not.
Yeah but the wiring is completely different between 90 and 91... That's the year the rest of the world switched to dual plug heads on the 2.3l mustangs... Cali started in 90 that's why I was asking... The manual you found I see it says 89-90 at the bottom was it a Haynes or something?

I also have this

And this