Tail light/Stop Lamp Checker problem HELP!

[svxcess]

I have recently run into a wierd problem on my 96 SVX. My electrical system has always worked flawlessly... until tonight.

As I was driving, the "Stop Lamp" light on the dash came on. When I applied the brake, the light went off, only to come on again once I released the brake. I stopped the car and checked my rear lights. With just my tail lights on, BOTH filaments in each bulb were on, when I applied the brakes, the brake filaments got brighter. Released the brakes and both filaments still continued to glow each of the four rear bulbs.

After driving for awhile tonight, the "Stop Lamp" on the dash went out. Looking in the rear view mirror while applying the brakes, I could see that my brake lights worked as they should. I just thought everything was fine once more until the Maryland State Police pulled me over for having all four tail lights out. Brake lights still worked and all other electrical circuits work normally.

I wonder if the stop lamp checker in the trunk is the culprit. I don't know what would make both filaments glow when only the tail lights were on, what would cause the Stop Lamp on the dash to act in the opposite way (If there is a problem,it should only illuminate when the brakes are applied , not the other way around) I can only assume that the 10A taillight circuit fuse failed because of both filaments in all four bulbs drawing too much current.

Does anyone have any ideas? Has anyone bypassed the stop lamp checker relay and how was it done. Any information is greatly appreciated.


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[SilverSpear]

Funny, I am experiencing the opposite thing, all my taillights are working fine, even on braking, they are all lighting up, but when i push the brake pedal, the Stop Lamp thing comes on..

[b3lha]

Originally Posted by svxcess

Does anyone have any ideas? Has anyone bypassed the stop lamp checker relay and how was it done. Any information is greatly appreciated.

I know this doesn't help you, but it was done on our SVX by the dealer. They converted one of the JDM brake lights to a UK-required rear fog light and that was causing the light to come on. I think they must have taken the checker unit out completely because I can't find it. Whereabouts should I be looking for it? I assumed it was near the water bottle in the boot. I'd like to fix it if it's still in the car.

Phil.

[b3lha]

Originally Posted by SilverSpear

Funny, I am experiencing the opposite thing, all my taillights are working fine, even on braking, they are all lighting up, but when i push the brake pedal, the Stop Lamp thing comes on..

Check the wattages of the bulbs are correct.

[SilverSpear]

Originally Posted by b3lha

Check the wattages of the bulbs are correct.

mmm, does this affect the Stop Lamp light to go on??

[mohrds]

If both filiments are on when you turn on the taillights, it could be a ground problem.

I think the SVX uses a single ground wire for the rear lights.

[svxcess]

Originally Posted by b3lha

Check the wattages of the bulbs are correct.

Problem solved! My thanks to insight from b3lha and mohrds.

I checked the #5 fuse under the dash (10A) and it was blown. I replaced the fuse and all of the symptoms came back (dual filaments illuminated, Stop lamp on the dash illuminated without brakes applied, etc.)

I replaced all four rear bulbs and the problem went away; everything is now working perfectly. Some of my tail light bulbs are older than others. Maybe increased resistance with age or a difference in wattages between bulbs upsetting the electronic "balance". Anyway, things seem to be fine once again and I want to thank all of you for your help.
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[mohrds]

John,

Which brake light bulbs are you running in this car. I know in your last car you had some higher power bulbs. Any long term test reports to update us on?

Doug

[svxcess]

I have been using the "brite bulbs" for about 4 years now, first in my pearlie which you saw at Lafayette, and now in my 96 Polo. In the tail light/brake light configuration they tend to burn out a little more quickly than the stock bulbs (about 1 bulb every 9-10 months.) This may be partially due to the alternator wiring upgrade, which has me running at 14.3 volts most of the time. I usually keep a dozen of the 1077 bulbs handy, in case something happens where I lose all four bulbs at a time.

As far as the 1015 bulbs in the front and rear turn signals, I haven't burned one out in over four years. Remember that I don't have front running (parking) lights and the only time they are on is when I'm signaling a turn. Same with the rear turn signals.

Overall, I feel the dramatically increased visability of the bulbs, in all conditions, far outweigh their slightly shorter lifespan. Plus our bulbs are so easy to change or replace.

[SilverSpear]

My problem is also fixed, the wattage thing... thanks guys