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MGB '71 MGB brake lights

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GaryBeu

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We've traced the two wires from the switch and cleaned connectors. Bulbs look OK. Took out the switch and cleaned it. When we push the button, nothing happens. Tested the two contacts on the switch for ohms and get continuity with switch off and same zero reading when button is pushed. I cut the two wires and touched them together and still nothing happens. Any suggestions?
 
do yu have a volt meter? can you check and see if you have 12 volts coming into the switch?
 
Duh...I got so involved with everything else that I didn't think about whether or not I had voltage into the switch. I'll check that in a little while. Thanks. :smile:
 
...and you do have the key on, right.

Also, be warned that continuity and lighting of a test lamp does not mean that the wires are passing enough amps to light the brake light. From hard experience I ca. Assure you that corroded connectors (especially those on the lamp socket) can test fine for continuity but not. E able to carry much current.
 
Well, I checked and yes, I do have 12 volts to the switch. So...I assume that the switch is bad. Does anyone have a switch I can buy cheaper than the $24.00 plus shipping from Moss? :smile: Thanks.
 
If the switch is bad then you should be able to short the contacts and have the brake lamps light up. Something isn't making sense about you having zero ohms across switch but brake lamps don't light. They should be on all the time unless switch is shorted to ground.
 
Part of my problem (I think) was that I'm not far enough back in time :smile: I didn't realize that the ignition switch had to be ON for the brake lights to work. Learning all the time :smile:
 
GaryBeu said:
Well, I checked and yes, I do have 12 volts to the switch. So...I assume that the switch is bad. Does anyone have a switch I can buy cheaper than the $24.00 plus shipping from Moss? :smile: Thanks.
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also, you should be able to check the switch - if it has 12 volts running through, switch in switch off - 12 V on 12 V off

the switches are pretty solid
 
Well...we wasted a LOT of time because of my brain fart. I have those more often than I'd like to admit :smile:. All is well with the brake lights and I definitely learned something so it wasn't all bad. Thanks for the comments and suggestions. The combination of them lit the bulb in my head that had gone very dim! Carla and I really appreciate it.
 
GaryBeu said:
Well...we wasted a LOT of time because of my brain fart. I have those more often than I'd like to admit :smile:. All is well with the brake lights and I definitely learned something so it wasn't all bad. Thanks for the comments and suggestions. The combination of them lit the bulb in my head that had gone very dim! Carla and I really appreciate it.
Click to expand...

So, what was it? At least in terms of brain farts you are in the right place! I (we) have them all time.

:wall: :square: :whistle: :cheers:
 
The main problem was not knowing 40 year old technology AND not being mechanically inclined to start with...I have multiple problems, eh? :smile: We are rebuilding this car so it is on jacks and we're going through it one thing at a time. The brake lights worked properly all the time but I didn't understand...I had taken the light switch out in order to look over the master cylinder. When I pressed the switch, no brake lights (key was "off"). Checking turn signals, etc. (key "on") pushing the switch turned tail lights off. This was all correct, of course, but I didn't know it. Sooo... there's my big brain fart. It'll never happen again!!
 
Tony...Thanks. I've printed it off and really am using it. Sometimes I get so focused on a problem that I can't see the picture :smile:.
 
Dave...I expect a LOT MORE brain farts. Just not this same one, hopefully! Thanks for all the help so far. We really do appreciate the understanding from experts to "uninitiated" pseudo mechanics!
 
I know we've sort of said this before but, Carla and I REALLY appreciate the assistance we've gotten on this forum. Nobody has treated us like fools even though we don't know what we're doing and we ask questions that "everyone" knows the answers to. Thank you all very much.
 
:iagree:
 
Thanks all...it's great getting such excellent feedback.
 
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