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Electrical ECM testing

  • Thread starter Thread starter Exrace89GT
  • Start date Start date Mar 24, 2020
E

Exrace89GT

Member
Mar 29, 2019
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Lompoc, CA
Mar 24, 2020
#1
  • Mar 24, 2020
  • #1
I have a used A9L that I know nothing about. Still has the factory seal. I got it in a trade. Want to use it on my ‘89 GT. So who do I send it to to have it tested?
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
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Mar 25, 2020
#2
  • Mar 25, 2020
  • #2
Usually, you can tell a bad computer by removing the cover and looking at the circuit board. Use a magnifying glass and check all the caps for dark looking fluid...check for ashy white corrosion...and check the circuit paths for burn marks or broken paths...last but not least check for cracks around soldering points.
 

jrichker

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Mar 25, 2020
#3
  • Mar 25, 2020
  • #3
Exrace89GT said:
I have a used A9L that I know nothing about. Still has the factory seal. I got it in a trade. Want to use it on my ‘89 GT. So who do I send it to to have it tested?
Click to expand...
The 5 speed 89 GT used an A9L, so there is nothing to be gained by swapping it for another A9L unless the one in the car is bad,.

Don't put an A9L in an auto trans car, you will damage the computer.
 
Reactions: 90sickfox and General karthief
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Exrace89GT

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Mar 29, 2019
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Lompoc, CA
Mar 26, 2020
#4
  • Mar 26, 2020
  • #4
Thanks guys. Car had no ecm when I bought it. Was a race car and stripped of part of the wiring including the ecm wiring. Got the A9L in trade for extra parts I had.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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#5
  • Mar 26, 2020
  • #5
How much of the original wiring is left?
Are you planning on replacing the wiring?
 
E

Exrace89GT

Member
Mar 29, 2019
90
16
18
Lompoc, CA
Mar 27, 2020
#6
  • Mar 27, 2020
  • #6
Most of the wiring inside the car is there. Nothing in the engine compartment, but I have a 89 harness for there. Some wires cut by the right kick panel. I posted pictures last year but I don’t remember getting any response.
 

jrichker

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#7
  • Mar 28, 2020
  • #7
Exrace89GT said:
Most of the wiring inside the car is there. Nothing in the engine compartment, but I have a 89 harness for there. Some wires cut by the right kick panel. I posted pictures last year but I don’t remember getting any response.
Click to expand...
PM me your email address and I will send you a complete Ford Factory 89 Mustang electrical diagram set. The zip file is 2.5 MB and is too big to fit through Stangnet's email gateway.

The plug shapes on the diagrams match the plug shapes on the actual plug. The diagram is divided up by the layout of the car. The first diagram is for the very front of the car, and it works its way to the rear of the car page by page.

They are in a zip file format to reduce the size of the package. If you don't have Windows 7 or Windows 8, or later, you’ll need WinZip or other Windows archive tool to extract them from the zip file.. See www.majorgeeks.com - Download Freeware and Shareware Computer Utilities for a free download.

You will need the Adobe Acrobat viewer which is also a free download – www.adobe.com/products/acrobat/readstep2.html - Adobe Reader download - All versions
 
E

Exrace89GT

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Mar 29, 2019
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Lompoc, CA
Mar 28, 2020
#8
  • Mar 28, 2020
  • #8
Jrichker, Thanks but I have the factory Ford wireing diagrams. So far I’ve been able to identify one set of wires with plugs.But the cut wires are a little harder as there is no plug even close to them. There are a total of seven cut wires. I’ll get back on it next week as the weather is supposed to be warm and sunny.
 
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