Headlight switch primes the fuel pump? no Key? Other Questions - Ford Mustang Forums : Corral.net Mustang Forum
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post #1 of 2 Old 04-26-2016, 11:48 AM Thread Starter
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Headlight switch primes the fuel pump? no Key? Other Questions

Okay, So trying to get my car back up and going, Someone had taken out the old dash/body harness and cut it up, so I found another harness from a car I had and removed the entire harness from it moved it over into my car and have some odd issues going on.

Basic Information

1987 Mustang LX 5.0L sedan

Wiring for complete car came from a 1989 LX 5.0 Hatchback

Body harness issues,

Key on fuel pump primes, Engine starts as it should

1) Key off, key out of switch, Press the headlight switch and the fuel pump relay comes on and primes the pump, on 3 seconds and off, just like I switched the ignition with the key.

No head lights, only half of the cluster works which is the speedo side.

2) key off, key out of switch, (Unplug the cluster and the problem goes away)

I want to solve the headlight priming the fuel pump first.

I don't think this would be an issue with the cluster, but it could be, but I do believe some circuit is connecting when I put the cluster in, to power up the relays for the eec and the fuel pump, From what I have read these are powered up by a ground, so what could be happening to cause this or what wires could I check first?

on a second note....the picture I am attaching, where do these two plugs go? one goes out through the fire wall on the drivers side and towards the headlight harness and the other goes down to the kick panel into a square plug.

Attached Images
File Type: jpg 13096227_10208016368179458_8146412139849532234_n.jpg (58.7 KB, 8 views)

1987 Sand Beige Coupe 1 or 47 LX somewhere
1981 T-Top Coupe..blew up so went back to the basics
2005 Mustang GT Convertible. ..Few bolt ons
1998 SVT Contour dd
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post #2 of 2 Old 04-26-2016, 11:17 PM
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too blurry to tell

89 GT gr-40, KB2200(10psi), tweecer R/T,LC-1, 22gal cell, w/tailpipes.
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