Really fast turn signal

[nerraw117]

I am having a problem when I turn on my turn signals they will flash very very quickly, in the meantime making all the other dash lights, brake indicator, whatever else is running, dim down when the turn signal flashes. Does this sound more like a bad ground or a bad flasher module? Thanks.

 

[dremu]

I am having a problem when I turn on my turn signals they will flash very very quickly, in the meantime making all the other dash lights, brake indicator, whatever else is running, dim down when the turn signal flashes. Does this sound more like a bad ground or a bad flasher module? Thanks.

I'm voting bad ground. Any time the brake or other lights do anything when the blinkers are supposed to be on, my experience has been that the blinker ground is bad and so the juice is finding some other way to ground. A very loooong and annoying way.

The fast blinker is generally due to higher resistance, i.e. one of the bulbs is out, so a really fast blink says the resistance has gone way up, i.e. there is no ground. My experience of the blinker units failing is that they just don't blink. (OTOH, for $3 or $4 or whatever, who cares. I splurge and replace the metal cans with the solid state ones that aren't load-dependent, works better for towing when you have trailer lights, etc.)

Anyway, it's easy to test: just swap the blinker box from the hazard one. (Assuming yours has two -- I know my '74's do, but I can't remember about them newfangled 80's trucks )

-- A

 

[nerraw117]

where is the blinker box? the metal cans you talking about the turn signal relay?

 

[dremu]

where is the blinker box? the metal cans you talking about the turn signal relay?

Again, I donno about the newer trucks, but the old ones have the two metal cans on the fuse box. They aren't relays, they're some kind of mechanical oscillator (maybe thermal?) You can get new ones that have the relays, and are controlled by a transistor circuit -- that's the solid state I was talking about.

-- A