Randy V

Still getting a bulb warning even after cleaning all sockets and trying 2 other lamp control units.

All lights are illuminated and same type.

Anything else to check?

Mrmerlin

connections to the rear side markers the tag lamps and the third brake light

SeanR

I replied to this hours ago but Rennlist took a dump. Make sure you have the proper wattage bulbs in the rear side markers. I believe they are 5w.

Petza914

All the rear bulbs need to be replaced in pairs. If you end up with an impedance mismatch from one side to the other, you'll get a warning even if all the bulbs work fine. Had that same problem on my car. Bought a complete set of rear bulbs from Mark Anderson and never had the problem again.

dr bob

There's probably a case for testing each of the lamp circuits from the bulb-check unit to make sure they are correct and matched side to side. DMM on Ohms should do it.


I had a couple sleeves of GE #58 (IIRC) bulbs in my collection, and use them in the markers and tail lights, with 1157 in the brakes and the front turn/marker. I've never had to change a rear turn or backup bulb. The #58 are a little bright for the side markers, perfect in the back though. Better to be a little extra bright on the sides I'm thinking. In case that blind driver's seeing-eye dog isn't looking, or the front-mounted white-tipped curb feelers are bent. The bulb check works great, alerts me when there's a failure.

We moved into a community of white-hairs, few of whom should be behind the wheel at all much less when it isn't full daylight. White-knuckler ride-along adventures. That's who we get to share the roads with these days. They are in your neighborhood too.

z driver 88t

^^^This.

Especially if you changed them using what the chart at the auto-parts store says to use. The Sylvania chart at most Advance/Auto Zone/Pep Boys says for side markers to use a 10W, 5008 bulb on 928s. This is not correct. You need a 5W bulb or it will throw the error light. Happened to me several years back and took a while to figure out what was causing it.

Alan

Randy,
Incandescent bulbs deteriorate over time but not very predictably - they will take lower current as the filament degrades (narrows in places) and becomes more resistive. (usually you will see a dark residue on the inside of the capsule - bulbs get overall dimmer too as a result) The only lights monitored are Brakes & Rear Markers (including rear/side markers). The warning message tells you which (assume it's rear markers?).

Put all fresh bulbs in (8 bulbs) or at least replace any pairs that are darkened as a starting point.... make sure all are correct wattage as you replace

Another possibility is poor or intermittent connections or grounds for the rear cluster/bulbs (or rear side markers). Does the bulb warning come on soon after turning on lights? or only during driving? (e.g. bumping connections around), while illuminated are all the lights equally bright?

Alan

Randy V

Now that I think of it, when I installed the clear side marker lenses I also replaced the bulbs with coloured LEDs.

I never got a bulb warning back when I did the swap but now thinking that the circuit is now seeing a voltage discrepancy and throwing the warning.

atb

Proper wattage as cited in the DEVEK catalogue:

Snark Shark

I had to re-flow the solder on the big double induction coil inside the bulb warning module. I guess it's heavy enough to wear out the solder when you drive over bumps and such. Hopefully it won't come to that, but it wasn't hugely difficult.