theandies

They flash at normal speed when the headlights are off but slow when they are on. Its not rally a big deal since they work but I'd rather them flash the same whether the lights are on or off. I've not looked at the flasher unit itself yet or even replaced it. Any ideas before I spend some $$$$$.
Thanks

SH-60B

You're probably seeing this at idle? The alternator is making the minimum of amperage at idle, the headlights are enough of a tax to lower the power through the flasher, making it take longer for the flasher to heat up and break the circuit. The cure, IDK.

theandies

Maybe but I do notice it when at speed like coming up to a turn in a turn lane. And I do like to take the corners so they are not usually take too slowly.
I'll check the flasher and see if it's the correct can this week while I'm fixing my leaky heater hose.

brent319

would a solid state flasher eliminate that? If it bothers you it might be worth a try.

theandies

I would think so since conventional flashers work on current and heat. If I find my flasher is not correct and I get the correct one and it still does it I'll spring for a solid state.

cardo0

I have never heard that before and don't understand how that could be.

Usually a change in blinker speed indicates one of the running lights/side marker lights are burnt out. Just have to verify all those lights with the headlights on - try operating a signal blinker also when you check as it maybe a signal light burnt out.

lionelhutz

It's pretty simple. The old mechanical flashers basically use a resistor to heat the mechanism until it clicks on. Once on, the main contact bypasses the resistor so the mechanism can cool again and click back off. Less voltage means less current in the resistor which means less heat. Since power is voltage x current, dropping the voltage by 5% would lower the heating wattage by almost 10%. Less heat means it's slower to close and flash the lights.

Only the filaments in the bulbs that are used for the signals would affect the flasher speed, not the filaments used for marker or running lights.

cardo0

Well didn't run out and look at which bulbs are dual elements. But I still suggest he checks them all. BFD!

lionelhutz

Doesn't matter what you look at, the lights that come on with the headlight switch won't affect the signals.

DUB

Correct me if I am wrong...but the front side marker lights are not only the running lights when the headlights are on... but they also blink when that side is having the turn signal turned on.

I would also have to confirm that all the bulbs are the correct bulbs. I ahve seen Corvettes that are supposed to use 1157 in the rear....but have 2057 in their place and it throws things off.

I would also make absolutely sure that you have a good ground going to the taillight sockets and front park signal sockets. I know your turn signals are working when the headlights are on...BUT when the headlights are on...BOTH filaments are sharing the same common ground in the socket...and it can possibly need to be cleaned.

DUB

pewter99

theandies

I know my lamps are 1157's ( where applicable) but not sure about the side marker lamps. I'll have to check them to see if they are correct and yes, all my lights work. I still haven't checked my flasher yet. I appreciate all the suggestions.

Capt Ken

Might also want to make sure the ground circuit is clean and tight. Headlight may be using enough current to make a bad ground in the turn signal circuit show up.

DUB

Respectfully...this does not make sense. The amount of current the headlights are using has nothing to do with the turn signals. The circuit that powers up the headlights can make them shine is not the same circuit that makes the running lights and turn signals work.

The importance of clean good ground does make sense at the park/turn signal/brake/taillight sockets.

DUB

theandies

Some more information. When warming up to go to work I turned on the running lights and checked the blinker operation. Front running lights in the grill blink. Tail lights blink. Front side marker lights blink. Rear side marker lights do not blink. Can someone with a '71 verify that's bow it should be. Maybe I have a different problem.
Thanks

theandies

TTT

Looked at my flasher. It's a 224 with what looks like an original capacitor on it. Not sure if 224 is the correct one as I looked on Rockauto (I know, not the most reliable parts house for vintage cars) and they have three listed. One electronic version and two 522's.

'75

Rear markers are only markers and should not blink. Sounds like the lights are blinking correctly.

DUB

You car is CORRECT.....the rear side marker light DO NOT blink.

So what I wrote in post #11 is correct......the front side marker lights do two different things. They are running lights when the headlight switch is on...and when the turn signal for that side is used..it blinks. And if the headlgith switch is NOT on...the front side marker light blinks when that side of the turn signal is used.

DUB

theandies

Update:
I checked and cleaned all the rear tail light grounds. Checked the socket grounds and they are good. Checked rear bulbs - Both 1157's. Checked side marker lamps (front and rear) both 168's as call out in the owners manual. The two rears were not marked 168 but I have some laying around and changed them out. No real change in blink rate with the headlamps on. Checked the flasher again, original capacitor checked good. Tried it without the cap - same thing, slow blink. Looked at my wiring schematic and see there are two chassis grounds on the front harness but I cannot find them. Anyone know where the factory attached these grounds? I also see that it also gets a ground from the back of the alternator. This ground is good.

'75

I believe there is a ground wire screwed to the lower drivers side front of the core support.