Warning Lights at Startup

stereomonostereo · Post by **stereomonostereo** » 03 Jul 2012, 15:35

This may be a dumb question, but according to the 93 Volvo 940 manual, all of the warning lights should illuminate when the ignition key is turned on. All that i'm getting is the Check Engine, Oil Pressure, Seatbelt, and SRS. Is this normal?

Post by **jimmy57** » 03 Jul 2012, 16:26

No, there is a small gauge wire plugged onto the back of alternator. It may be unplugged or the alternator has an issue.
If you unplug that wire, use something like a paper clip stuck in the connector on the wire and you then touch it to somethine metal on engine those other warning lamps should come on when key is turned on. If the lights do come on then alternator is the issue. If the lights do not come on then the wiring between the alternator and the dash will have to be diagnosed for the problem.

elmo_allen · Post by **elmo_allen** » 03 Jul 2012, 16:33

Would this work for a 1999 S80 2.9LNT as well? Hardly any of my warning lights come on, this includes the Check Engine light. It has been like this since I bought the car in 08, and I thought it was normal until about a year ago. Still haven't fixed it and I would like to.

Post by **jimmy57** » 03 Jul 2012, 19:09

That is a good question. The DIM (instrument cluster) is not direct wired to much of anything on a CAN networked car. The CEM may be using the alternator D+/61 (the skinny wire on alternator) signal as the decision of whether the lams are on for bulb check or not.
DO the same test by ground the skinny wire on alternator to see if the warning lights come on with key on engine not runnng.