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Passenger Brake/Hazard lights stopped working - new turn signal switch

Started by Jbrooks, November 08, 2021, 03:04:19 PM

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Jbrooks

I've been chasing an electrical issue with my car.  Six months ago I replaced my turn signal switch (thanks B. Gaines for the hint about removing the steering wheel), and everything was working great; horn, hazards, blinkers, brake lights, turn signals all worked.  After driving around for a few weeks, someone told me that my passenger brakes weren't working.  So I went home, checked them (verified wiring sequences with my shop manual) and they were working fine. 

Couple drives later, I kept checking to see that they were working, and I noticed the passenger brake/hazards weren't working one day.  I figured that a wire may have come loose from the connection under the steering column, but they were all just fine.  I re-plugged the connector and everything worked fine.  However, couple days later I noticed the same thing with my passenger lights working sometimes and sometimes not. 

Now they don't work at all (passenger brake and hazard), and I'm scratching my head.  When I turn on my running lights, both sides (passenger and driver sides) work (not a bulb grounding issue).  Did I get a crummy turn signal switch?  Any suggestions on what else I should check?       

Thanks in advance for any help!
Jim
67 GT350 #2260
"If you ain't first, you're last"

Cobrask8

Definitely in the switch harness/wiring, though taillights do not pass through the switch.

How are the grounds in the trunk? I bet they could be an issue. Clean, metal to metal contact only, no paint

Pcunder

Take this for for what it's worth.

I was chasing major electrical gremlins correcting the wiring in my 70 BOSS and, assuming the wiring is similar, I learned 2 things:

Everything goes thru the headlight switch AND
everything else goes thru the flasher/turn-signal indicator... with some going thru BOTH.

I replaced both and ALL problems I didn't create myself were GONE..!!!?? like magic.

One of my switches was flakey (intermittent) and the other was defective (broken). This assumes, of course, that you have all wires connected and grounded properly and with proper loads from operating incandescent bulbs, etc.... Don't forget the flashers! (There are 2; 1 for the blinkers and 1 for the E-flashers.)

These 2 switches ARE together the "brain" that routes virtually all the lighting signals. In today's vehicles, it's a computer but back then, it was 2 complexes of switches and re-routed wiring with double feeds, etc... Just look in the manual or wiring diagram of ALL the circuits that route thru them. I was shocked. The headlamp switch even has a circuit breaker built in that "breaks" when too much current is drawn and it overheats the circuit (the only difference between the 69 vs 70 is that CB...and the 69 rating is higher bcz it has 4 headlight vs 2). After the CB cools off for a while, everything works again "until next time". You can't imagine how maddening that can be when troubleshooting... I wanted to pull my hair out!!

Luckily, I had, all the manuals, tools, an electrician and a lot of beer/time. Oh yeah, I worked on computers for 38 years so I was not gonna let some 1970s "technology" defeat me..!!!

OK, there, I feel better now. Hope this helps..!!

tonys_shelby

I'm going with a bad turn signal switch again. I've heard the aftermarket ones are not that great, and because of the extra current draw from more bulbs on a '67 Shelby they burn out faster. I also heard the trick to keep the aftermarket switch from burning out it to switch to led lamps.

Jbrooks

My grounds are good.  I replaced the taillight harness a couple years ago, and I made sure the contact areas areas are bare metal.  Thanks for the input Cobrask8!

Pcunder: I replaced the headlight switch and my flashers when I replaced my turn signal switch, so I hope that has me covered.

tonys_shelby:  I read that comment about the load being too much for these new switches, and that they used the 1157s.  Searching on line, I can't tell if I would need an additional relay for the LED bulbs to work correctly, or if I can just switch them out with the conventional 1157? I went ahead an ordered a new turn signal switch, but I haven't decided about the bulbs yet.  For the LED bulbs, I can't tell if I would need the 1157s or the 1157r, or if there is even a difference between the two.

Thanks!   
67 GT350 #2260
"If you ain't first, you're last"

Pcunder

Ok, good...

I bought NOS OEM Ford stuff as I'd heard that some aftermarket replacement parts are...well, let's just say they're cheap for a reason. 

And I was damn tired of troubleshooting, testing, swapping... it was much more, of course, but shopping around online can save a few $.

Oh yes, I had 1 ground wire completely missing from the main connector to the turn signal switch as well as a crushed wire in the same harness (pinched almost in half where the steering is bolted to the dash.) so, I basically had 3 problems causing my weird symptoms. 

Also, I added factory sport lamps, OEM AC, an MSD box, and dual electric fans (drawing their power thru relays directly fm battery via fat fused hidden wires)


tonys_shelby

I used the warm white from NPD. The higher end ones, felt they would look more original when lit up. Look great can't tell except a little brighter.

Jbrooks

Did you have to add the electronic flasher for these bulbs?

Quote from: tonys_shelby on November 09, 2021, 11:50:29 AM
I used the warm white from NPD. The higher end ones, felt they would look more original when lit up. Look great can't tell except a little brighter.
67 GT350 #2260
"If you ain't first, you're last"


Jbrooks

Just a follow up, installed a new turn signal switch, LED tail lights, electronic flasher and everything is working like it should.  Thanks for all the help!
67 GT350 #2260
"If you ain't first, you're last"

S7MS427

JBrokks,

Glad you had a happy resolution to your problem.  Brighter tail lights should also give you some peace of mind knowing that those following you are much more likely to notice your braking action.
Roy Simkins
http://www.s-techent.com/Shelby.htm
1966 G.T.350H SFM6S817
1967 G.T.500 67400F7A03040