Hello,
Still trying to figure out why my SES light is on when it should be off and off when it should be on. If i disconnect the base timing set wire- the light goes out. If i disconnect the MAF it also goes out. But the light flashes codes fine (no codes[code 12]) It also works fine when i jumper ALDL A and B with the car running to watch the mixture. Could there still be something connected to this light from the old LG4 system? Anyone have a diagram for the SES light in a LG4? i Also noticed that my car has a sensor on the power steering pressure line- havent seen one on any fuel injected car.
I was working on a 83 LG4 (converted to regular carb) and removed the ECM and disconnected the harness- yet the SES light stayed on. Im thinking that this could be the same problem i have with my 86

 

The old ecm may have a lamp driver module and needs to be removed or bypassed.

 

Nice, where do i find the module?

 

I can't recall were they stashed it Too bypass it or just test it out I assume you are using a 1227165 ecm. disconnect pin a5 at the ecm. use a test wire and bulb and a 10 amp fuse in line. attach the fused line to a positive source the ecm grounds the pin a5. if this works ok rune a wire to the mil lamp.

 

I pulled the panel on the lower passenger dash and felt around up in there, Im not finding anything besides the ECM, duct work and an outside air vent. Is it inside the ductwork? inside the heater core box? There is just not much in there electrical wise outside what i have installed for the TPI setup

 

found a box screwed to the front of the dash, about 4 X 3" and an inch thick and black in color. It is attached to a metal bracket with two screws on the bottom. it seems to have a metal tab and wants to slide out toward the driver side, but it wont slide far enough to come out of it's bracket. the bracket seems to be secured further up than i can reach. Do i need to pull the dash pad to get at another screw?

 

Mines been on since I installed my headers, I just let it stay on it

 

Is that box the Light driver module?

 

That looks like a cruise control module.

https://www.thirdgen.org/forums/elec...t-does-do.html

 

damn. another guy was saying it is right in that area, but from what you can see in the pix, that is all i have. I need to find this board and unplug it. Getting tired of staring at this light for no reason. Maybe Vader knows where it is.
Go to take someone for a ride and get, "whats that light on for?" every time.. lol.

 

If it is there it is located in a light green plastic box bye the passenger side hvac duct. I do not have the schematics for this but you might pm vader, rbob or sonny_T.

 

Frustrated, spent all day peeking and feeling all over under both sides of the dash, behind the radio/ comfort controls. all along the I/P harness, by all of the heater ducts. Im not seeing anything blue or green anywhere. I guess that the 86 LG4 didnt have a LDM? If thats the case is there something wrong with my ECM?

 

disconnect pin a5 at the ecm and start the car. If it is grounded yes you have a bad ecm.