I've had a P0650 issue for a while, which is an issue with the check engine light itself which in my case won't light. Clear code and it and it comes back. I took it apart and replaced the bulb, even though the old one tested ok. Still not fixed. From what I read the light is controlled by the PCM which grounds the light to activate it. Here's what I've checked and noticed:
* Have continuity between CEL bulb and underhood accessory junction box
* When key in and light should be on, I only see about 3V going to bulb
* If I test between a pink 12V switched ignition going to the gauge cluster and the CEL ground, I read 12V
Any thoughts? Not as familar dealing with these ground based circuits, and how/why only 3V gets through to the bulb. Any fixes or other things I should test?
