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A9L and 02 harness on an '87

  • Thread starter Thread starter larrym1961
  • Start date Start date Jan 9, 2011

larrym1961

5 Year Member
Dec 18, 2010
570
36
49
Idaho Falls Id
Jan 9, 2011
#1
  • Jan 9, 2011
  • #1
On the A9P or A9L thread, there is several postings of changing 02 harnesses or re-pinning for using an A9P or A9L ECU after a trans swap from factory AOD to T5, or Tremec 3550 in my case. when I did the swap on my '87 5.0, I was using a C3W auto computer(came with mass air conversion kit). I am now using an A9L, have had for a couple months now. I do a perodic code check, I had 2 codes after swapping from the C3W to the A9L. After doing some wiring & pinning (that I did not do during mass air conv. codes #95 & #29) I now have consistent code 11's.

I have read on the post that if the 02 harness is not changed or jumper wire re-pinned you can toast an A9P or A9L computer, If you use one of these ECU's after a trans swap from stock. My question is, I checked my 02 harness and my '87 and it does not have any jumper wire on the harness. So am I OK? or do I need to find a 02 harness for a 90's manual trans Mustang and swap it in? So far so good on the A9L (I have a spare A3M) but I don't want to run the risk of toasting any of them.

Any input would be helpfull!
 

liljoe07

5 Year Member
Feb 18, 2009
1,622
363
124
Cartersville,Ga
Jan 9, 2011
#2
  • Jan 9, 2011
  • #2
No Jumper= No way to fry an ECM from the 02 harness.
 

larrym1961

5 Year Member
Dec 18, 2010
570
36
49
Idaho Falls Id
Jan 9, 2011
#3
  • Jan 9, 2011
  • #3
That is what I kinda figured since I have used the A9L for several months and a A3M before that with no problems. I just needed to be sure! Thank you for the info!
 
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