1980 DL. The left turn signal is working overtime. It starts at the normal interval and suddenly starts flashing about twice that speed. Both bulbs flash, just faster than they should. Yesterday I pulled the front bulb while it was in this state and the interval went back to normal. Replaced it and it was okay for a few seconds and started doing it again. Fooled with it some more and it has worked normally since. But I'm thinking it must have something to do with the flasher. I have no diagnostic info on that unit. Has anyone experienced this condition?

There was no corrosion to speak of on either bulb. But one of the things I did (when I said I fooled around with it some more) was to clean the surfaces on that front bulb. Mostly I just cleaned up the center contact. It was dull gray, now it's shiny silver. It's worked so far so maybe that was it. If it happens again I'll check the grounds, etc.

agree with previous poster. additionally, the smallest bit of oxidation can cause these thingsto flake out... it may work, but the bad contacts, bad ground, or oxidized connectors introduce JUUST enough resistance to trigger teh light out rapid blink trigger (usually comes one when a light is dead, or thats teh geneal idea anyway).

-rt

Double time flashing is the cars way of telling you there is a problem with a bulb/socket/wiring/ground. It is designed to flash faster to indicate a problem. The flasher is ok. Poor contact in bulb socket or bad ground is common. The turn signals are not conected to the bulb failure warning system.