[TR] Continuing brake light bulb failure

[Jim Muller]

On 29 Aug 2008 at 8:25, thenicholls at verizon.net wrote:

> Thanks for the reponse.  The scenario is I replace the bulb.  Bulb works 
> with lights on and when brake is depressed.
> 
> At some point in the future, when the brake is depressed, light does not 
> get brighter.

Yes, but...but...  A few other replies have already touched on the 
issue but I'll continue anyway.

When you say the light does not get brighter, you are describing the 
overt symptom but not any underlying cause.  So a key question is 
this:  Is the bulb burning out???  If you just take out the bulb and 
re-insert it, does it work again?  If you insert that bulb in the 
opposite side, does it still not work?  If the same bulb can be made 
to work again, in either side, then the problem is wiring.  If you 
put the working bulb from the other side into the problematic socket, 
does the problematic side now work properly?

If the bulb is actually burning out, then you have faulty bulbs, or 
bulbs intended for 6v, or some weird electrical thing sending high-
voltage spikes into the line (but which somehow aren't burning out 
anything else).

Now, it is possible for a burned out bulb to work intermittently if 
the filament is still intact enough to lay across the wire it is 
supposed to touch.  Such a bulb can seem to work but after minor 
physical agitation not work, and then maybe even work again.

It sounds like you have some bad bulbs, but you need to verify this.

-- 
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+