Check Engine Light Staying on

[Turbostangman]

I wired up a Check engine light and ALDL Port on a Kit car that has a 84 GN engine transplanted into it. I wanted to check the codes to see if I could find a miss that has plagued the car since I got it running.

I wired up the ALDL port as follows to the wires going to the 434 connector off the ECU harness;
ALDL Terminal..............434 Terminal
Pin A............................Grnd
Pin B wht/Blk...........Wht/Blk Pin E
Pin D Brn/Wht..........Brn/Wht ECU Pin A5 (spliced with wire to CEL)
Pin E Orange.............Orange Pin J
Pin F Tan/Blk..............Tan/Blk Pin H
Pin H Grey..................Grey Pin D

The other side of the Check Engine Light (CEL) is wired to a ign 12v source as shown in the main wiring schematic.

The problem is when the key is turned to the on possition the CEL comes on and stayes on. When I jump terminals A & B it doesn't do anything, it just stays on.

Did I do something wrong or is something else going on?

Someone PLease help!! I am getting SO AGGRIVATED!! and I need this fixed ASAP!!

Does anyone have any idea what is going on?

 

[Turbostangman]

Anybody?

 

[gofstbuick]

Is the other leg of the lamp going to ground? It looks like A5 drives the lamp, and power is derived from the fuse block, but the oil pressure sender completes the circuit to ground. I hope I'm not missing something here.

 

[gofstbuick]

also, do you have an ignition feed to the circuit and is the feed to circuit 419 okay?

 

[Turbostangman]

Thanks for the reply!

I must not have the schematic you have. Mine just shows the other side of the CEL going to a 10A fused pink/blk wire which I hooked it to.

I always was under the impression ECU's only grounded circuits likt Injectors, IACs, etc.

 

[Turbostangman]

Originally posted by gofstbuick
also, do you have an ignition feed to the circuit and is the feed to circuit 419 okay?

What is that? another connector plug like 434?

 

[gofstbuick]

Circuit A6 feeds the ECM fuse, the ignition switch and the SES light. Circuit A5 is the ECM ground circuit, and it feed the other pole of the SES light. Circuit A9 is a 5v reference and feeds terminal B of the ALDL. Circuit A12 is an internal ECM ground and looks like there is an additional ground outside of the ECM. It appears the ignition switch powers the other side of the ECM fuse and the SES light. I'm looking at an 87 factory manual. So I hope this will provide a better explantion. Please ignore the previous post and use this as a reference.

 

[Turbostangman]

Sent you a PM.

 

[gofstbuick]

posted replay

 

[gofstbuick]

I should clarify, I sent you a PM