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Discussion Starter · #1 ·
Gentlemen –#
My brother and I are putting a '94 Mustang GT 5.0 HO motor in a Miata. The instalation includes the original '94 ECU (T4M0) and '94 wiring harness (F4ZB-12A581-N160SBR). Since there's obviously not any extra room, we're removing wiring components that aren't needed.

There's one connector we've been unable to identify. Its a long rectangular 24 pin male connector that is secured to it's mate with a bolt. Three of the 24 pins are unused and we don't have the mating connector. Does anyone here have an idea what this connector connects to? Pictures are at: wetsystems dot com slash miata. [the forum won't let new members post URLs]

Thanks for your help!
Bill Thackrey
 

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Gentlemen –#

There's one connector we've been unable to identify. Its a long rectangular 24 pin male connector that is secured to it's mate with a bolt. Three of the 24 pins are unused and we don't have the mating connector. Does anyone here have an idea what this connector connects to? Pictures are at: wetsystems dot com slash miata. [the forum won't let new members post URLs]

Thanks for your help!
Bill Thackrey
That is the connector to the vehicle's Constant Control Relay Module or CCRM. Ford used CCRMs on many car lines begining in the late 80s and early 90s. Essentially it is a electrical module containing several relays that are controlled by the PCM (computer) to turn on/off certain things like the electric fan or AC clutch compressor. Mustangs did not use a CCRM until 94. Not being familiar with the 94-95 Mustang harness I cannot tell you whether you will need any of the CCRM functions in you Miata conversion or not. Schematically some of its wiring is shown here:

http://www.veryuseful.com/mustang/tech/engine/images/Mustang-94-95-CCRM-AC-Diagram.gif

There are more 94-95 schematics here:

http://www.veryuseful.com/mustang/tech/engine#95-95Diagrams

I read your other post and I doubt you will find a physical diagram of your 94-95 harness- Iver never seen one.

I only put EFI 5.0Ls into old Fairmonts - your project sounds awesome.

Good luck guys

T
 

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Discussion Starter · #3 ·
>TWR2003 - THANK YOU!!! That is EXCELLENT information! Now to find out if we need the CCRM. Which leads us to the PCM. Too damn many modules, if you ask me. :) It looks like 12V to the injectors may me switched through a relay in the CCRM so we may need to find one. Or wire around it. Thanks again. This is very helpful information.
 

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IMHO an 87-93 comp and harness would be better suited for that. It is less complicated and is a better computer for performance and modification.

There is a standalone harness available from Ford racing just for this purpose.

http://store.summitracing.com/partd...400070+4294925143+4294839062+115&autoview=sku

Of course you still need an A9L and you can get a used 89-93 Mustang engine harness cheaper. But this is brand new and is plug and play.
 

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IMHO an 87-93 comp and harness would be better suited for that. It is less complicated and is a better computer for performance and modification.

There is a standalone harness available from Ford racing just for this purpose.

http://store.summitracing.com/partd...400070+4294925143+4294839062+115&autoview=sku

Of course you still need an A9L and you can get a used 89-93 Mustang engine harness cheaper. But this is brand new and is plug and play.
I would have to agree that you would probably be better off with a harness set from a 89-93. The 92-93 set was the best/simplest as the FP relay is integrated directly into the EEC harness instead of being in the vehicle harness as it is on all pre-92 harnesses. Im not sure if there are any compatibility issues when using a 89-93 harness set on a 94-95 dressed engine. The FMS harness is very expensive but is designed for non-Mustang installations. With what you are doing its cost may be small compatered to the overall cost of your project. Only you can make that judgement.

If you decide to stay with the 94-95 harness -which you may have to - it looks like you will most likely need the CCRM as I believe it contains both the EEC and FP relays.

Good luck

T
 

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Used the older motor/harness/ecu on mine--easier and the ecu is more mod-friendly than the SN94/5.
 
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