QuestionQUESTION: Hello, ok i have no dash light brake or dim lights, the only way i have ANY lights is we hold the brights on, we believe it's the BCM, but cannot find it, what do you think?
ANSWER: Hi Amanda,
The bcm is located on the back side of the fuse box, under the dash. The two are electrically linked to one another, and are separated by sliding them apart. But I would question whether the issue is with the bcm. Are you saying that you only have high beam headlamps, and that you have no low beam headlamps and no brake lamps, and no illumination lamps for the instrument cluster (or do you mean no warning lamps on the cluster?)?
The brake lights are not controlled by the BCM. Instead check fuse 13 in the box under the hood near the battery. If that is OK then check the brake switch operated by the lever of the brake pedal.
The low beam issue could either be the dimmer switch itself being faulty, or the low beam relay which is the 5th one (last one) in the in-board row of 5 relays in the underhood fuse/relay box. Try substituting another relay in the box with the same part number for the low beam relay to see if that corrects the low beam problem. The BCM does play a role in the low beam light circuits but I would first verify the relay and including fuses #6 and 7 in that underhood box and the fuses that power the bcm (see below).
On the dash lights, are the lights for the A/C heater control also not working, or are they OK? I would check fuses #2 and 6 in the fuse box underdash as those power some of the circuits in the BCM that may power the dash lights.
Only after you do that would I look at replacing the BCM.
Roland
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QUESTION: Ok checked all fuses ( didn't know there was another fuse box) but all are ok, and i mean ail lights, i actually have brake lights and by high beam i mean holding the high beams on at the turn signal arm...No cluster lights either or low beam lamps, checked with new bulbs not it, would you check switch first?
AnswerHi Amanda,
There are two ways to check out the multi-function switch (on the steering column which includes the high/low beam selector). One is to remove the upper and lower shrouds on the steering column that are directly behind the steering wheel. There are three screws on the under side of the column that hold the two shrouds together. Take a try at removing those screws without first taking off the steering wheel. If you can, then you have direct access to the multifunction switch and its plug. The switch/plug interface has 10 pins that are numbered on the plug itself. When the switch is in low beam position it should show continuity between pins 9 and 10 (i.e. 0 ohms resistance using an ohmmeter, or a continuity tester). And for high beams position it should show continuity betweeen 9 and 12, and when you 'hold' the high beam on too. If not, then I would buy some electrical contact cleaner in a spray can and try spraying it inside the switch with the stray applicator to see if you can restore the contacts. If that fails and it seems there is no spring tension that would hold the contacts together then buy a new multifunction switch. Let me know if you can't gain access directly by removing the shrouds and I can xerox copy and postal mail you the pages that show how to remove the steering wheel.
The other approach involves measuring for continuity between pins on the plugs that are on the front and rear side of the fuse box under the dash. Again this is a detailed procedure which I would do second if you can't get to the multifunction switch easily. But I do suspect it is the multifunction switch internal contacts that are not being 'made' either due to dirt/corrosion/mechanical failure.
On the dash lamps, those are controlled by the main headlamp switch and you might try rotating the switch's knob as that will sometimes just have an intermittent dead spot in the cluster dimmer resistor that is varied by twisting the knob. Otherwise, we have some more circuit testing to do.
Do you have an ohmmeter or continuity tester?
Roland
Roland
