Non Functioning Check Engine Tell Tale

[F16driver]

Hi guys,
Here's an odd one for your pondering. 87 325ic, the check engine tell tale light on the bottom of the instrument cluster does not come on during start up. It should come on as part of a self test for a few seconds when the ignition key is turned from off to on/run. I pulled the instrument cluster and removed the bulb. The bulb test ok for continuity. Lets assume the bulb is ok for our discussion. I did a search for check engine light (CEL), but none of the returns helped for a light that doesn't work. I looked at Bentleys for a wiring diagram with the CEL but didn't see one. I did not open the cluster to look inside yet. I assume that since the CEL has its own wire running to it, the inside of the cluster is not part of the problem. Assuming its not the bulb, what else could be causing the lite to not come on. I don't have any other issues (that I know of) so I don't think its a fuse. I didn't see a separate fuse listed for the CEL. My on board computer works fine. My active check system works fine. I plan on pulling the cluster again and using a test light to see if the CEL is getting power when I turn the ignition on. Thanks in advance for any suggestions.

[Wayne 962]

Interesting. I would check the connections in the connector using your test light and also check the resistance across the two terminals with the bulb removed (may be a short circuit?). Other than that, if you can isolate the wires for the bulb from the wire harness from the DME, then you may be able to test for voltage on the line.

Also, a bad ground in the cluster or in the gauge area may give problems like these, as will wire harness issues...

-Wayne