I recently fitted a set of SS C B's and after proberly now more than 4 hours of use the lamps blew. I checked the voltage at the Lamp holder and discovered 13.92 Volts.

I contacted SS and very helpful they were too, But they said they have found some other cars with exsessive output from the alternator/battery system.
Has anyone else experienced this problem and is ther a cure ? as I dont want to keep replacing lamps like they are going out of fashion.

You'll find that on any car the voltage is rated at 14.4V whilst the engine is running.

When idling it's about what you've reported.

Engine off..11.5-12.5 depending on load.

I agree - 14 volts is quite normal -
bulbs blowing is more likely to be due to insufficient cooling for the bulbs or switching them on/off too rapidly - ie flashing. Try making an extra ventilation hole for the bulbs to dissipate a little more heat and see if that improves bulb life.
regards,

Paul W

We only know of 4 cars that have a problem with high voltage. This is well under one percent of the amount of Cibie users.

Subaru state that the voltage output, with the vehicle running, should be 12.5v +/- 1.5v.

All bulb manufacturers work on a target voltage of 13.7-13.8 volts and a vehicle with a higher rating will suffer shorter bulb life.

If your Cibie light bulbs fail within the first year of purchase, send in the old ones with a SAE and they will be replaced, free of charge.