ECU and harness connection advice

[EBarnes]

First, I am not (yet), and EFI guy, so assume I am totally ignorant! Also, I'm travelling so nothing is around for me to look at...

I have a Ron Francis wiring harness (from FFR). I bought a 5.0 HO out of an '89. It has wiring from the injectors, and a few other plugs + battery cable. Neither has anything that looks like it plugs into an ECU though.

A friend bought a 5.0 that has an A9M ECU and harness. He's switching to carb and wants to give me a good deal on whatever I need.

So, do I just need the ECU, or is there a piece of the harness that plugs into it, in turn connecting to the harness. I'm guessing it's the latter.

Also, what is a reasonable price for the ECU (and wiring should I need it).

Thanks!

[michael everson]

You will need the wiring that goes from the salt and pepper shakers to the ECU. The salt and pepper shakers are the large black and white plugs hanging off the back of your engine. I would think $100-$200 is reasonable
Mike

[riptide motorsport]

Ecu's run anout $100, the wiring I don't know...........ask him to throw it in.

[EBarnes]

Thanks for the info guys (and the description Mike, it helps).

Anxious to get this thing started, in the car!

[OCCPete]

Ford Racing used to sell the EFI harness and it had a really good step-by-step manual for connecting the harness to the chassis harness. I used the Ford harness and connected it to an EZ Wiring chassis harness. It really wasn't too hard.

Summit racing sells their own version of the harness now and the manual is pretty much the same as the Ford manual: http://static.summitracing.com/global/images/instructions/sum-890120.pdf

New harness from Summit is $499: http://www.summitracing.com/parts/SUM-890120/


Pete

[Stengun]

Howdy,

The A9M ECU is out of an automatic car. Probably not a problem for you to use it in a stick shift car.

Paul

[tcoon]

You should get the standalone 5.0 efi harness from Ron Francis. It dovetails beautifully with the chassis harness, only a few wires to hook up. I think trying to sort out a stock engine harness with the chassis harness would be more difficult unless you have a good working knowledge of the ford factory harness. I have used both the Francis harness and a painless and they are both very user friendly, but the Francis is a lot cheaper. There are many ecu's which will work, for the challenge series (manual tranny) most prefer the a9L although the A9P seems to work just as well. You can usually buy one on craigslist for $60-100, or more on eBay from salvage yards.

-T

[NTGuru]

For those of you looking, i am in the process of converting a 95 5.0 to 93 spec due to the abailability of parts (and the fact i did not want to give the 95 harness a HairCut). so here is what i have found. advanced auto parts and autozone both sell the cardone remanufactured piece. 78-4352 is the cardone part number and it sells for $87.95 with a $45 core. this with the ron francis harness, a stock or mallory/msd TFI distributor and an intake manifold, throttle body and maf is all that is needed to complete the conversion. i am looking at the wiring diagrams now to see if you could use a 94-95 (these are a much better eec processor) with an early harness by changing the processor pin outs and to see if it will work with the TFI distributor instead of the remote tfi module. sorry for getting off pont, but here is the processor info.

Cardone Part Number 78-4352

Advanced auto link http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product__3803147-P_248_R%7CGRPTUNEAMS____

Autozone Link http://www.autozone.com/autozone/parts/Cardone-Reman-Engine-Control-Computer/1993-Ford-Mustang/_/N-izpyuZ9gsp8?itemIdentifier=11297_371409_0_


other info: http://api.viglink.com/api/click?format=go&key=9bd10022a072455a29499296f3a7374a&loc=http%3A%2F%2Fwww.allfordmustangs.com%2Fforums% 2F5-0l-tech%2F142892-5-0-h-o-eec-iv-computer-part-numbers.html&v=1&libid=1336954151460&out=http%3A%2F%2Fwww.fordfuelinjection.com%2F&ref=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26r ct%3Dj%26q%3D5.0%2520eeciv%2520computer%26source%3 Dweb%26cd%3D1%26sqi%3D2%26ved%3D0CIsBEBYwAA%26url% 3Dhttp%253A%252F%252Fwww.allfordmustangs.com%252Ff orums%252F5-0l-tech%252F142892-5-0-h-o-eec-iv-computer-part-numbers.html%26ei%3DH02wT8P2PIeu6AG08KyYCQ%26usg%3 DAFQjCNFNQLZz5RZ1fn6ZWjDn5_loiYI_CQ&title=5.0%20H.O.%20EEC-IV%20computer%20part%20numbers%3F%20-%20Ford%20Mustang%20Forums&txt=Ford%20Fuel%20Injection&jsonp=vglnk_jsonp_13371692053152

[skullandbones]

I used the Summit EFI harness as OCCPete mentioned. If you can get the A9M for about $75 to $100 you would be OK. You will have to pay a core charge if you get it from the auto parts store. I read that the A9L and A9M are for 5 spd trans and the A9P was from an AOD version. So the A9M should work fine. I paid the price of the Summit harness because I wanted major tech support. You said you weren't and EFI guy so for your first project, this would be a good route. I can say that because I got excellent tech support at a moments notice (many conversations during the wiring process). You will get an EFI education talking to those guys who are gear heads, too. I would probably tackle the stock engine harness (2 pc) but I saved a major chunk of time doing it the way I did. I did waste a couple of days with the stock harness before deciding against it. The other advantage is the Summit harness has some nice features for diagnosis and efficiency. See the manual page 12 enhanced features. Good luck, WEK.

[rocket]

Guys,
I have a few questions regarding the RJM and Ron Francis (RF) looms. This is for the #28 car I'm building for Karen. It will be street legal (barely!) with all lights and turn signal operable.
1. Do you cap the Inertia wire on the RJM and splice the inertia wire on the RF kit if you are not using a
an inetia switch?
2. The RJM has transmission plugs marked man and auto. Are these needed? What are their function?
3. Is there any preference/ reason on which system powers the fuel pump?
4. Any tips that will help eliminate problems will be greatly appreciated.
My Challenge car was a breeze compared to this.
Thanks,
Rick Anderson

[EBarnes]

Thanks again for all the input everyone. Last week I ended up ordering a harness from Mustang Medic for $150. He has gotten nothong but rave reviews, and is building the harness for the A9M (AOD), while also being able to convert to the manual ECU. It is built to interface with the Ron Francis harness, and includes a new EFI harness, too.

Also interested in answers to rocket's questions!

[tcoon]

When I did my hot rod I used the inertia switch and fuel pump circuit from the engine harness and it seems to run fine. I did not use the transmission plugs since I'm running a manual TKO it wasn't needed. Also there is a VSS circuit for the computer which is not needed. I suppose these might be needed if you're using a computer controlled auto trans.

-T

[EBarnes]

Rick, do you have the RF instructions? Mine are at home, but I'm 90% sure it has you connect the two wires together for the inertial switch if you forgo it. I could easily be confused though!

Chuck (Mustang Medic) explained the difference on the AOD and Manual ECU as pin 30 basicallys sensing the transmission being in Park (nuetral too?)...

[EBarnes]

Sorry, didn't get to finish that...

""AOD - +12 volts during start is applied to that pin for AOD start. T5 - the clutch switch OR the T5 TRANSMISSION NEUTRAL SENSE SWITCH (my emphasis) is sensed for the T5 start mode..."

Not sure if that info helps or not, but I was assuming the Trans harness had something to do with these modes.

[skullandbones]

Correct on the inertia switch, just close the loop on that circuit. You can do the same on the trans safety circuit but personally, I would use it (front switch on the T5 not sure on the TKO). WEK.