blowing lamps

my j reg 240 gle has twice now had a puff of smoke come out the r/h side heater vent, & the instrument lights have failed(the back lights for the clocks if you like) no fuses blow & i cant for the life of me see any obvious burns in the wiring, or any marks on the back of the speedo. i changed the dimmer rehostat & the main on/off light switch, but it still happened again. any ideas?

Hi, Can you wire the dimmer out of the circuit to see if that was/is the issue?? Ordinarily, when the dimmer goes the dash lights go to full power by default... Current surge from a failed dimmer perhaps? Seems unlikely to happen twice mind... Des. . . ;)

Check your voltage from the alternator with the engine running. Blowing lamps can be a sign the regulator is not doing its job and the voltage is too high. Or you could just have dodgy lamps? Andrew

Sounds like the Voltage "stabiliser" / "Regulator" on the rear of the instrument cluster ;)

ok guys, thanks for the speedy replies. this stabiliser/regulator, can you give me a clue as to what it looks like? is it integral to the instrument panel?

thanks for the help. the gauges all work OK, its just the instrument lights that go off., however, i cant for the life of me find any sign of burning. its a bit worrying as my last car was totalled due to a dash wiring fault.

DP240 I would suspect that the rheostat is being overloaded, you should trace all the wiring for all lights that are controlled by the rheostat, the last time I had this problem it was a trapped wire under the center console. Mister T.

thanks MR T, i'm never too sure about wiring, not bothered by mechanicals or body work(retired painter) but wiring always seems like a black art! i have a good auto electrician near my work, so i think he will be taking money off me soon.