Check Engine light ques

[HammaK5]

Alright on my 87 R30 454fi the check eng light wont come on. Ive tried replacing the bulb still no change. My question is can I use a test light somewhere on the diagnostic port to flash the codes? By the way the light never comes on not even durring starting.

 

[4X4HIGH]

Not sure about using a test light on the ALDL connector but you can use a scanner to get your codes.

 

[dyeager535]

Something is wrong with the bulb test then. IIRC, the ECM provides the ground path, probably first need to verify (again, if necessary) the bulb is good, you have good contact at the bulb, and finally, that there is 12V to the bulb with key in run, engine off.

 

[HammaK5]

Thanks dygear I think the problem with the light is in the printed circuit film on the back of the cluster. I checked the grounds and I have voltage at the harness think Ill just use a test light there for now.