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Brake lights

Posted: 04 Oct 2010 14:55
by bahbzilla
I couldn't find any references to this using the search function, but I can't imagine that I am the first with this problem.

The last thing standing in my way to getting on the road is the lack of brake lights (although I did buzz around the neighborhood a bit... Woo Woo!!!). My other lights are working ok. I figured it was the switch, so I found an appropriate replacement at NAPA, but still not luck. Then I used a piece of wire to eliminate the switch and close the circuit for testing, but they still did not come on. Are there any common points of failure for the brake lights other than the switch?

Bob

1980 TR7 DHC
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Posted: 04 Oct 2010 22:29
by RadioGuy
Go to John Clay's site and download the manual it has a schematic. He also has a TR8 schematic that I think has the same brake wiring layout. http://web.mac.com/jclaythompson/iWeb/Technical/Intro.html Oh...by the way....Thank John for all the info !!!

I'd start with the hazard switch and a test light and go from there, the brake lights go through that switch. The hazard switch is notorious for problems. FWIW

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Maintained on Saturday…Drive on Fun-Day !!! 1976 FHC - 1980 DHC

Posted: 04 Oct 2010 23:48
by nick
Grounds are always suspect in these cars.

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nick
'79 TR7

Posted: 05 Oct 2010 00:33
by silverseven
Silly question but did you check the fuses???

also note; I had one heck of a suprise the first time I removed the socket from my tr7........as its highly suggested to disconnect the battary before reconnecting the socket [;)]

Ron.
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Posted: 05 Oct 2010 01:00
by Hasbeen
I have had a problem with the electrical connection of the globe holders to the casting.

The alloy can become lightly oxidized, [not showing as corrosion] & prevent proper contact. In this case lights will work intermittently.

The globe holders can also loose their "set" to some extent, so they don't lock in tightly enough. A little careful work with long nose pliers usually fixes this.

I have found that after fixing, these minor problems tend to return, so regular maintenance with contact cleaner is useful.

Hasbeen

Posted: 05 Oct 2010 05:03
by jclay (RIP 2018)
Really dumb question here. Did you check the bulbs to see if they are burned out? I would also check the ribbon wiring under the mat in the boot.

The brake lights are fused by fuse 15-16, so if your wipers work the brake lights should also. The circuit goes directly from the switch to the lights and is not connected to the Hazard circuit.

Hope that helps.

Clay

[url="http://web.mac.com/jclaythompson/Site/Welcome.html"]My Triumph Site[/url], [url="http://web.mac.com/jclaythompson/iWeb/Technical/Intro.html"]Technical Stuff[/url], [url="http://homepage.mac.com/WebObjects/FileSharing.woa/53/wo/HJMTK8gsojtwKleP.1/0.2.1.2.26.31.97.0.35.0.1.1.1?user=jclaythompson&fpath=Triumph_Articles&templatefn=FileSharing4.html"]Download Page[/url]

Posted: 05 Oct 2010 13:27
by bahbzilla
Thanks for all of the input. The hazzard switch was cleaned up to fix a turn signal issue and is clean and ready to go. I thought about the fuse as Clay mentioned and checked the wipers, which also work ok. Checking the bulbs, is not such a dumb idea, since I kind of failed to do that[B)]. I was also wondering about the ignition switch as a possible point of failure. I believe the brake light circuit runs through the ignition switch and they only work with the key in the run position? Is that another possible point of failure? I will check bulbs, sockets and grounds in the boot and report back in...

1980 TR7 DHC
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Posted: 06 Oct 2010 14:11
by bahbzilla
Cleaned the contacts, bent the contacts in the bottom of the socket up a little to tighten things up and changed the bulbs, and we have brake lights! The old switch was bad, but the replacement (pontiac) works fine. Next time maybe I will check the basics before I cry for help... Thanks for all of the suggestions.

1980 TR7 DHC
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Posted: 06 Oct 2010 19:01
by DNK
<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jclay</i>

... <font size="3">I would also check the ribbon wiring under the mat in the boot</font id="size3">...<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

There's a mat in the boot?

Don
"No More Cars For You"
71 TR6- Perpetual remodel
80 TR7 V8 Kick in the pants

Posted: 07 Oct 2010 01:27
by catmanboo
what you did to the socket prongs will work- for a while, at least. had same problem! after finding voltage at sockets, naturally ground,(earth in Brit-speak) or lack thereof, had to be the culprit. take a bit of steel wool or fine-grit abrasive & polish the areas where contacts on ALL sockets hit the housing, & dab a bit of silicone grease or similar at these places. solved my problem- permanently, I hope[:D]