Speedway Turn Signal Switch

[Oban Ron]

I need some help guys. My 4 way hazard lights recently stopped working. I replaced the clamp-on switch with the Speedway Universal heavy duty one and an electronic flasher. I wired it according to the schematic with the brake switch connected to the red wire on the turn signal switch. The turn signals and 4 way hazards work great with my LED's, but now my brake lights don't come on. With the brake pedal pressed, therefore the brake switch closed I measured approx. 11 volts at the brake switch without the turn signal switch connected. When I connect the turn signal switch to the brake switch the voltage drops to about 5 volts and the brake lights don't work. Any suggestions? I guess the turn signal switch could be defective, but short of that any suggestions?

 

[old round fart]

Sounds like a short to ground on brakes circuit. Look good at turn signal switch wiring.

 

[Oban Ron]

I ran a direct line from the brake switch to the turn signal switch and same result. When connected the voltage is pulled down to about 5V and no brake lights. The turn signals and brake lights were working before with direct lines and they are working really well now, as well as the 4 way hazard lights. Nice and bright. I would think if I had a short to ground in my wiring it would effect the other turn signal leds. That is why I am thinking the switch is bad. Any other ideas or am I off base here? Is there a way to wire the brake lights direct (bypass the turn signal switch) and still work with the turn signals?

 

[Indycars]

The more info you can post the more input you will get if a person doesn't have to go
looking. Wiring diagrams are important to understanding the problem.

Is this your turn signal switch ?



Is this your electron flasher... is it from Speedway ?
12 Volt Electronic Flasher

I'm not a wiring expert, you really need someone like PotvinGuy or maybe Fletcherson to respond.

My best guess comes from the unusual fact that you are getting voltage drop from 11 volts to 5 volts. That
would make me suspect the the wiring to flasher. If there was a short the voltage would be close to zero
and there would be smoke. If there was an open the voltage would be voltage would be battery voltage. So
the flasher with it's internal wiring being the only thing I can see dropping the voltage to 5 volts.

Double check your wiring to the flasher.

What is your battery voltage, should be about 12.65 for a fully charged automotive battery ???

 

[AusBucket]

That's a pretty poor schematic, the RED from the brake Sw disappears into the loom never to be seen again!

 

[Oban Ron]

Yes, that is the switch, the flasher, and exactly how it is wired. With the turn switch disconnected I do have 12v across the brake switch. The brake switch is working, along with the turn signals, and 4 way leds. They are nice and bright. The LEDs on the turn signal switch are also working fine. When the turn signal switch is connected the voltage on the red wire at the switch drops to 5V. All works except the brake LEDs.

 

[Spanky]

That's a pretty poor schematic, the RED from the brake Sw disappears into the loom never to be seen again!

I think if you look at the diagram as the red wire being the 7th wire coming out of the turn signal switch and going to the brake light switch it looks OK.

Ron, re: the voltage drop, does this have something to do with the fact that the turn signal is using the same bulb as the brakes when both are activated?

 

[Oban Ron]

I’m using the tear drop leds in the rear. As far as the voltage drop I don’t know why. That’s why I am asking for advice. I’m leaning towards a defective turn signal switch. The turn signals are working great and using the same circuit. I’m just going to order another turn signal switch to see.

 

[AusBucket]

G'Day Spanky,
Thanks for your comment, it's not obvious to a person that doesn't work with wiring diagrams a lot, (me for one) Can see now you mention it that's the only place it could go to. Ron is probably on the right track about the Sw being faulty.
Regards,

 

[old round fart]

Looking at the schematic if the switch gets the 12v from the battery there should be no reason you should not have brake lights as the Turn signal switch should not be in the circuit. I think there must be a
Problem in the turn signal switch. Look inside for a wire loose. When a turn is called for one brake light wire is disconnected so that one gets its power from the flasher.

 

[fletcherson]

What happens if you ground the brake switch wire? Better yet, do you get a voltage reading at the red brake switch wire from Turn signal switch? As mentioned earlier, what’s with the 11 volts?

 

[fletcherson]

What happens if you ground the brake switch wire? Better yet, do you get a voltage reading at the red brake switch wire from Turn signal switch? As mentioned earlier, what’s with the 11 volts?

Im wondering if you have voltage backfeeding through the turn signal switch or if it is shorted to ground to the brake switch terminal.

 

[fletcherson]

The other thought is to disconnect the the lights and use a test light or multi meter to verify output, basically isolate the switch from the car lights and wiring to verify if the issue is the switch or beyond. My thought is there may be a undiscovered issue because there was an issue before. Perhaps the previous issue was not in the old switch? Maybe a chaffed wire, etc? Just a thought.

 

[Tbuilder]

I used that same turn signal on my model T and had the same problem when I wired it up. If I recall correctly and I possibly do not, the problem was the flasher. The flasher for the brake/signal lites is not the same as the one for the hazard lites, so if you have switched the flashers or wired them up wrong (as I did) then you will have the problem you have described. Just a thought based on my experience.

 

[old round fart]

Also the flasher for the old lights and LED’s are not the same.

 

[GreggDaniels]

When I put LED taillights on my car the front blinkers didn't have enough resistance to make everything work so I went to O'Reilly auto parts and got a flasher that was supposed to work with LED's but no luck. I brought that back and got this from Jeg's and everything worked fine after that. https://www.jegs.com/i/JEGS/555/11108/10002/-1

 

[Indycars]

I bought the same flasher in February 2015, damn if I would have just waited 6 years I
could have saved $6 dollars.

 

[PotvinGuy]

Ack. This drives me crazy. The SEMA guys sell us Chinese crap at a big mark-up and give us lousy instructions to boot. And they sell "LED" flashers for $20 ($33 at Ron Francis, who's been gouging us for years), when all you need is to add a $1 parallel resistance (resistor or light bulb) to fix the flashing. I suspect your turn signal switch is toast. Let us know how the next one works. And not to worry; we have the brainpower here to fix even the ugliest mess.

 

[AusBucket]

I have always done the resistor add on when fitting LED tail lights, saves a lot of stuffing about changing flasher cans. It became a bigger problem in later years with can bus systems looking for resistance in the filamants and then you drive down the road with the blinker lights twinkling. Most of the manufacturers have corrected this now, but there was some unreal price gouging going on at the time for the fix. Mate of mine was quoted $2000.00 AUD to correct the fault on his Merc SUV!!

 

[Oban Ron]

All fixed. The inline brake light switch was intermittent. It worked fine, prior to me replacing the turn signal switch, but without going near it, afterwards I found it worked intermittently - mostly not. I was dropping the voltage across the switch when it was closed. I replaced it and all good. FYI - I used the LED flasher provided with the turn signal switch from Speedway (no resistors) and my LED's work fine. Thanks for your help, guys!