Brake Lights Always On...AGAIN

Maintenance advice to keep your Spider in shape.
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CharlieB
Posts: 237
Joined: Sat Aug 22, 2015 8:01 pm
Your car is a: 1976 Fiat Spider

Brake Lights Always On...AGAIN

Post by CharlieB »

Well I thought I had resolved an issue where my brake/stop lights were always on.
I adjusted the switch at the brake pedal and all was well for a couple weeks.
The problem has started again and no amount of adjustment (in or out) will fix it.
So, I'm assuming that the switch itself is bad. Does anyone have any tricks for removing the switch?
I can turn it only so far then it just will not budge. The plastic near the wire connectors is cracked so I can't get a
wrench on it to take it out.
Any ideas?
Thanks
Charlie
1976 Fiat 124 Spider
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18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Brake Lights Always On...AGAIN

Post by 18Fiatsandcounting »

I'm assuming if you remove one of the wires to the switch, the brake lights go off? If so, then you're probably right that the switch is bad. If you remove a wire and the brake lights stay on, we have another problem to figure out... If you loosen the white wire, don't let it touch ground as it will blow a fuse since this wire has 12 volts on it.

Going by memory here, but I'm pretty sure that the switch has a locknut on it, maybe even one on each side of the bracket that it attaches into. Maybe the locknut(s) isn't loosened up? If that's not the issue, then either the back of the switch is hitting something as you try to back it out, or the threads are all buggered up so it won't easily unscrew.

-Bryan
DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Brake Lights Always On...AGAIN

Post by DieselSpider »

Yes the switch has a lock nut and if it was forced so that the threads got distorted it can be difficult to remove. Thankfully the switch is available at Advance Auto Parts for $12.99: https://shop.advanceautoparts.com/p/int ... t%20switch

Image

The local store was able to get me one from the local warehouse the next morning.

The threads on the steel mounting bracket were a bit off so I had to put a tap through them to chase them out and clean them up. I normally use TapMagic when cutting new threads however in this case I used PbBlaster since it was a cleanup.

The switch itself can be delicate so if you do not loosen the lock nut using a thin open end wrench on the hex on the threaded shaft and turn it by the black switch body instead, you will spin it in the metal ferrule that joins the two sections of the switch together damaging the contacts inside.

As Brian mentioned though, unplug the switch first and if they still stay on then you likely have a short circuit somewhere.
CharlieB
Posts: 237
Joined: Sat Aug 22, 2015 8:01 pm
Your car is a: 1976 Fiat Spider

Re: Brake Lights Always On...AGAIN

Post by CharlieB »

Thanks guys.
Bryan, yes if I remove a wire the lights turn off so no short.
DS you were right about the threads, they were a bit 'warped'. So, I finally got the switch removed and should have a new one later today.
Thanks again gents,
Charlie
1976 Fiat 124 Spider
DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Brake Lights Always On...AGAIN

Post by DieselSpider »

If the contacts are fused together you still may have a short or high resistance in the circuit causing the switch to heat up so plug the new switch in before completely installing it, manually hold it in the on position and feel it for any signs of it getting warm/hot just to play it safe.

I put a fused power lead directly to the battery in the trunk and made up a set of relays to take the load off the switches since the relays only draw a few milli-amps greatly reducing the electrical load on the lighting circuits. All rear lights (Brake, running and turn signal) are a lot brighter now.
CharlieB
Posts: 237
Joined: Sat Aug 22, 2015 8:01 pm
Your car is a: 1976 Fiat Spider

Re: Brake Lights Always On...AGAIN

Post by CharlieB »

Will do, thanks
1976 Fiat 124 Spider
Online
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Brake Lights Always On...AGAIN

Post by 18Fiatsandcounting »

Charlie, my guess at this point is that you simply have a bad switch, and maybe it was on its way out when you first started having this problem, and while adjustment helped for a while, it finally bit the dust. Anyway, let us know what you find out.

-Bryan
CharlieB
Posts: 237
Joined: Sat Aug 22, 2015 8:01 pm
Your car is a: 1976 Fiat Spider

Re: Brake Lights Always On...AGAIN

Post by CharlieB »

Ok, I finally put the new switch in last night. Brake lights are now working properly.
Thanks for the help guys.
Of course, now it's too cold to drop the top, so my next project is replacing the mangled convertible top.
Thanks again,
Charlie
1976 Fiat 124 Spider
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18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Brake Lights Always On...AGAIN

Post by 18Fiatsandcounting »

Good to hear, Charlie, and thanks for letting us know.

The big question regarding replacement tops is always: Cloth or Vinyl? That seems to be a personal decision, and there are advantages to each. My preference has always been cloth, but it is admittedly more expensive.

And note that there are two slightly different versions of the top, mainly in terms of the dimensions and shape along the front edge (where it attaches to the windshield). I believe your '76 would use the earlier version, but I'd verify rather than relying on my (sometimes faulty) memory.

-Bryan
DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Brake Lights Always On...AGAIN

Post by DieselSpider »

18Fiatsandcounting wrote:Good to hear, Charlie, and thanks for letting us know.

The big question regarding replacement tops is always: Cloth or Vinyl? That seems to be a personal decision, and there are advantages to each. My preference has always been cloth, but it is admittedly more expensive.

And note that there are two slightly different versions of the top, mainly in terms of the dimensions and shape along the front edge (where it attaches to the windshield). I believe your '76 would use the earlier version, but I'd verify rather than relying on my (sometimes faulty) memory.

-Bryan
More accurate would be 78.5 and earlier originally used the CS1 top however since the CS1 front bow has not been that readily available for some time many of them have had a failed CS1 bow replaced with a CS2 and now require a CS2 top. So you really have to inspect the shape of the bow to verify regardless of the year whether it needs a CS1 or CS2.
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