Flashers stopped working.

[thx997303]

All four flashers stopped working today. Brake lights and everything else works fine. Might mention that when I am stopped, turning on the flasher turns off the brake light. Also, it seemed the signals flashed pretty slowly prior to this happening. Possibly the flasher relay?

The hazards don't work either, but I am not sure they ever worked. Only figured out the switch today. Hadn't thought to pull it.

 

[LCAM-01XA]

Aye, your flasher is dead - replace it with an electronic HD one if you can swing it, 25 amp rating and it does not care how many lights you got and always flashes the same speed.

Brake lights get turned off by default when the turn signal switch is engaged in either direction, it's then up to the flasher to make them blink accordingly - with a dead flasher the switch kills brakes-on power as designed, but the blinky action power that is supposed to come next never happens.

Hazards follow the same principle of turning off brakes-on power then supplying pulsing power for the blinks, but they have their own flasher relay that is independent of the one used while making turns.

What model year truck are you working on?

 

[thx997303]

It's a 90' F350 CCLB 4x4. More than just the year I know. Keep forgetting to update my sig.

So, seems the fact the brake light turns off confirms that the signal switch is working. If only I had made it to the parts store on time yesterday, I'd have it fixed by now.

Thanks.

 

[sle2115]

Aye, your flasher is dead - replace it with an electronic HD one if you can swing it, 25 amp rating and it does not care how many lights you got and always flashes the same speed.

Brake lights get turned off by default when the turn signal switch is engaged in either direction, it's then up to the flasher to make them blink accordingly - with a dead flasher the switch kills brakes-on power as designed, but the blinky action power that is supposed to come next never happens.

Hazards follow the same principle of turning off brakes-on power then supplying pulsing power for the blinks, but they have their own flasher relay that is independent of the one used while making turns.

As usual, what he said! lol

 

[LCAM-01XA]

I asked for model year so I can tell you where the flashers are. The one for the regular blinkers is always in the fuse panel. Then one for the hazards on your '90 is kinda hidden in an odd spot, it will be all the way on the right side of the dashboard - pop your glove box off and it's to the right of the opening, could get to it from below too if you pull the kick-panel.

 

[thx997303]

Well, it wasn't that flasher. Replaced the one in the fuse panel, and no change. Flashers still don't work. Though, oddly, now my hazards work. Can hear that flasher on the passenger side going like it should.

Now I'm confused.

 

[thx997303]

Well, there is 12 volt going to the L leg of the flasher, but nothing to the X leg. Using the multifunction switch doesn't change this.

Maybe my multifunction switch has failed?

 

[thx997303]

Do the multifunction switches switch power or ground? Need to know to test.

 

[thx997303]

Either way, the new and old flashers both cycle when voltage is applied.

 

[thx997303]

Well, the connector for the flasher switch had backed out slightly. Guess the locking tab had broken at some point in the past. Squeezed them together, now they're working.

 

[sle2115]

Well, the connector for the flasher switch had backed out slightly. Guess the locking tab had broken at some point in the past. Squeezed them together, now they're working.

Yep, I've seen that happen as well...at least you found it!

 

[Cainon]

I asked for model year so I can tell you where the flashers are. The one for the regular blinkers is always in the fuse panel. Then one for the hazards on your '90 is kinda hidden in an odd spot, it will be all the way on the right side of the dashboard - pop your glove box off and it's to the right of the opening, could get to it from below too if you pull the kick-panel.

is this the same for an 85 f350?

 

[riphip]

85 is on back side of fuse panel