Will "all" harnesses with the 2 BLACK connectors work with the 7747 ECM even if the other ECM was a diffrent number? I know that the RED/BLUE ECM's wont hook up to a 2 BLACK connector harness. I got some harnesses from a junk yard out of 89 and 91 fullsize vans and they have the 2 BLACK connectors but the ECM's are gone so I don't know what was plugged in? I have seen diffrent ECM numbers with the 2 BLACK connectors but are they the same?
CK5
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TBI harness and ECM compatibilty question
- Thread starter GMC Truck
- Start date
dave w
1/2 ton status
The safe answer, NO. GM used a couple different ECM's for TBI, 1227747, 1228747, and 1228062 are a few different ECM numbers that come to mind quickly. I know all the above listed ECM numbers used the 2 BLACK connectors. The odds are good that the harnesses you have are 1227747 harnesses, but check them with a wiring diagram. http://chevythunder.com/1227747_ecm_198892.htm
dave w
If I would not know the ECM that was on the harness could I simply change the pinout to match the 7747 ECM? There can't be that much diffrence since the motors are the same all the wires should be there just maybe not in the right order.
dave w
1/2 ton status
Yes, you can change the pinout to match the 7747 ECM. Usually about 95% of the time the color codes are the same.
Colors like:
Black wire with white stripe BLK/WHT
Pink wire with black stripe PNK/BLK
Light Green Lt GRN
Dark Blue Dk BLU
and several others!
dave w
TommyM
1/2 ton status
I compared my '90 8747 to my '91 (don't remember the ecm number, but it's the 4L80E). They were TOTALLY different pinouts.
Tommy
Tommy
