EEC numbers

[Gary Nicholls]

My 87 Ranger 2.9 has a bad EEC, I think, fails when warm. It has the number 12A650-BD1A, and at the local recyclers they have a unit from a 87 Ranger but the last numbers are BG1A. I was wondering what the difference was and if the BG1A would work in my truck, and not fry anything? I have not found anything on the 'net about those numbers.
Thanks!

 

[RonD]

12A650 is Fords generic EEC part number, still used today for any vehicles computer(EEC)

The suffix numbers like BD1A were revision and firmware codes but Ford never released a decoder for them


There is also a stamped number on the label, read here: https://web.archive.org/web/20110414065146/http://fordfuelinjection.com/?p=17

1994 and earlier EEC needs to match engine size, EGR or no EGR, manual or automatic and that's about it

2wd or 4wd didn't matter

Yours would start with E7 for 1987 so you should try to match that as well

 

[rusty ol ranger]

My 87 Ranger 2.9 has a bad EEC, I think, fails when warm. It has the number 12A650-BD1A, and at the local recyclers they have a unit from a 87 Ranger but the last numbers are BG1A. I was wondering what the difference was and if the BG1A would work in my truck, and not fry anything? I have not found anything on the 'net about those numbers.
Thanks!

What makes you think the ecm is bad?

 

[Gary Nicholls]

Thanks RonD for the awesome fast reply! The page you linked to is very useful, appreciate it.

rusty ol ranger
"What makes you think the ecm is bad?"

I lose power to the fuel pump after 30-60 minutes, measured right at the high pressure pump. Twice I had it towed home, but next morning it starts OK. Once it quit and I just left it for a couple of hours and it started and got me home OK. Then idled it on my driveway for 30 minutes and it died, thats when measured voltage to the pump. Then when I plugged in my code reader, key on, there was no response from the computer.
I used to repair electronics/computers, and I know things can fail when warm, and electrolytic capacitors in older devices seem to be one problem, though ICs and CPUs could also fail when warm.

 

[rusty ol ranger]

Thanks RonD for the awesome fast reply! The page you linked to is very useful, appreciate it.

rusty ol ranger
"What makes you think the ecm is bad?"

I lose power to the fuel pump after 30-60 minutes, measured right at the high pressure pump. Twice I had it towed home, but next morning it starts OK. Once it quit and I just left it for a couple of hours and it started and got me home OK. Then idled it on my driveway for 30 minutes and it died, thats when measured voltage to the pump. Then when I plugged in my code reader, key on, there was no response from the computer.
I used to repair electronics/computers, and I know things can fail when warm, and electrolytic capacitors in older devices seem to be one problem, though ICs and CPUs could also fail when warm.

I gotchs, yeah, no response from the cpu is not a good thing. When i read your original post i thought maybe you got some bad advice or something on why it was quitting, i know some guys will tell ya its somethin serious when it coulda just been a bad coil or something. But here i think you are correct.

 

[RonD]

Inside the EEC-IV, 1983-1994, are 3 capacitors.
They are known to leak after 20 years or so causing problems

They can be replaced, read here: http://support.moates.net/capacitor-repair-ford-a9l-ecm/

A9L was a V8 EEC-IV, but you have the same one, just programmed for V6

Picture of "clean" EEC-IV circuit board here: http://www.auto-diagnostics.info/ford_eec_iv
You can see the 3 Blue Capacitors

Worth a look inside

 

[decipha]

loosing power like that could also be the eec relay which is a very common failure

thats the first step to diagnosing any eec intermittent issue is replacing or jumping the relay to verify the ecu is getting full power (even a restrictive relay can cause some odd issues like dumping fuel)