Aaron Schulte

I'm about 10 wires away from being able to fire this thing up for the first time, but, I'm having trouble finding where/what these last 2 connections go to. There's a 7 pin by the master cylinder and a 4 pin by the ecu

Aaron Schulte

I was told the harness was from a 1989 but I have a suspicion it may be from a 93 because of a relay I purchased for the a/c by the airbox. A9L ecu.

Also in case you're curious. .030 over, forged pistons, stock rods/crank, e303 cam, 1.7 rr, gt40 explorer intake, 65mm throttle body, 73mm c&l maf, stainless headers, smog/egr removed, -6an fuel line and a good amount of porting/polishing on the e7's.

imp

When I did my 1970 Bronco, using a 1992 5.0 HO out of a wrecked police car, the harness given me had differing color codes from my Ford wiring diagrams. I wound up cutting open pretty much the entire harness, tracing wires as needed. It took 3 months! You can try wiring diagrams, if Ford, they will pictorially show each connector, as well as identify the color of wires. Beware that some of the connectors are very damned similar in shape, though, in any given harness. You may need to open up your harness to trace the wires from those two connectors. I'll look closer at them, try to ID them, but have to leave here to go back to your OP.

FWIW, I ran NO cats, the standard EEC-IV O2 sensors, used a rebuilt PCM from Auto-Zone, mounted it in the glove box. "Experts" told me it would not run without cats. Not only ran, but beautifully. Lived in Phoenix, smog test recorded Carbon Monoxide 0.00%!
imp

EDIT: Do you know the year your engine came out of, and whether your harness came out of the same car? Clearly, the harness is 1989 or later, as all had Mass Air beginning 1989; CA had it earlier, though, may a year or two. Sometime between '89 and '93 is when the frigging wire color codes changed. Sorry, I can't call out your connectors, unless you post pics looking directly into the connector, then, maybe. I have wiring diagrams galore.

Aaron Schulte

I pulled the engine out of a 89 lincoln mark vii...harness is from Ebay (sold as out of an 89 gt)

Aaron Schulte

It is actually an 8 pin plug with a (test)or single wire connector in the same bundle(connector from the stock 1989 2.3 mustang harness)...and a 4 pin by the ecu in the passenger footwell.(5.0 harness) I'm guessing the 8 pin by the master cylinder is gauges/instrument panel and have no idea on the 4 pin

imp

Right off the bat, the square gray one is the single connector of two which allow code checking: it plugs into the code scanner. It's mate is wide and thin, shaped like a bungalow-roof, and has three conductors. Those 2 are usually located together, bundled as they both get plugged into the scanner.

Give me some time to look over the prints. Each year has about 8 or 10 two-sided prints as big as your kitchen table! imp

wbrockstar

Im sending some info to you via pm because the individual who came up with this detailed harness identification writeup doesn't like anyone copying/ pasteing it,even if you post his screen name as the source,so he will get all the credit for it,so Im sending it to you via pm.Therefore,check your inbox shortly.

Aaron Schulte

thanks wbrockstar that answers alot of questions. So, I have a 92-93 harness not the 89 I thought I was buying, I have a 92-93 02 harness as well. So I guess the question now is to modify the wiring, find an 89 specific harness, or take the dash apart and install a 92-93 dash harness

Update.
I found a 89 specific harness on ebay....sent the guy an offer...I think that's gonna be the easiest way to go. I'll just have to resell the 92-93 harness...super inconvenient but will probably break even cost wise...but that means I have at least another week before I can fire her up.

Update 2.
Bought the 89 harness with fuel injector harness for $200 so that should be coming soon...I guess tomorrow is removing all the wiring from the engine and repinning the 02 harness so it doesn't fry the ecu

Aaron Schulte

Update:
So I got the 1989 5.0 harness...started water/leak testing....had a head gasket leak (my fault...originally installed backwards and when I flipped it some of the gasket material came off), replaced the head gasket and installed new intake gaskets as long as it was coming off. The 89 harness is all installed and everything is plugged in minus smog pump and egr. I wanted to check if it cranks and it did!!!!!! The harness I purchased didn't have a pcm relay (right by the ecu) but I found one on one of my spare harnesses and plugged it in(this is after I cranked it). My new issue I hope you can help me out with is that the fuel pump is not getting power...I can't hear it prime like normal when you turn the key. My guesses so far are either the pcm relay I pulled is wrong/broken (are there different relays???) or a wiring issue at the pump itself (pump is a brand new 255lph unit) I have the stock 90lph and a 160lph I had with the turbo setup. I'll start testing wires tomorrow. Is there anything else you guys think I should be testing/checking. Other than that I have to finish up a few vacuum lines and continue to leak check and check for bolt that need tightening.
From my research I found that if the pcm relay is wrong/bad it won't activate the ecu and hence wont turn on the fuel pump.

Thanks

wbrockstar

Yeah that's correct about the EEC relay.Once you turn the key on,the EEC relay energizes & supplies ignition on power to the ecu,fuel pump relay & a host of other components.The fp relay
has 4 wires going to it.
1 is "hot at all times"
1 is "hot with the key on"
1 is "hot & supplies power to the fuel pump and it also splits and runs to the ecu @ pin 19.Called fpm- fuel pump monitor"
1 is "ground thats cycled on/off by the ecu @ pin 22"

Normally a power wire is what triggers a relay to come on,but in the Foxbodys case,the ground is what triggers the fp relay to work and its controlled totally by the ecu.When the ecu cycles this ground on,the fp relay energizes.Another thing to be aware of is,the ecu uses the pip sensor pulse (from the distributor) to
verify the engine is rotating (it works like a crankshaft position sensor) When the ecu detects the pip pulse,it turns the fp relay ground on which energizes the relay & sends power to the fuel pump for start mode or run mode.If you don't hear the fuel pump priming the lines when the key is first turned on,go to the hatch area near the driver side taillight/trim and locate the inertia switch.Push the button to see if the switch is tripped.Youll hear/ feel a click if the switch is tripped.Now turn the key on to listen for the priming sound.The inertia switch kills power to the fp relay on 86-90 models if its tripped,disconnected or defective,so thats one of the first places to look if you don't hear the fp priming and the relay doesn't click when the key is first turned on and its a 86-90.The inertia switch will only kill power to the fuel pump itself,on 91-93 models,so if the relay doesn't click when you turn the key on,the inertia switch is not at fault .
Im posting a diagnostic port diagram, sequence of events diagram and a detailed fuel system diagnosis link below,so you can trouble shoot the problem.When the info tells you to ground the fuel pump trigger terminal on the diagnostic port,its labeled in the first diagram below.Just turn the key on,run a jumper wire from the neg battery post to the FP Trigger terminal and the pump should energize if nothings wrong.
One last thing: Im not sure if I asked about this yet or not,but are you running an oem style neg battery cable with included 10ga wire & pigtail with tubular connector that plugs into a identical connector,which is at the end of the main ecu/engine harness that lands near the battery tray area?? If you don't have this cable,its imperative that you come up with another means of running a wire to account for this ground,otherwise the fuel pump will run when the key is in the start position,but it'll shut off as soon as the key is released to the run/on position .

http://www.allfordmustangs.com/forum...gs.html#/enter