Shorting Out Brake Lights

1969VAGTX

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I have been dealing with an electrical situation on the GTX. I noticed that the brake lights don't work. There are actually two problems. One is the switch doesn't make contact with the brake pedal to turn the lights off. That I can address. However, when the brake light switch is connected it immediately shorts out the fuse. If I disconnect the brake light switch and install a new fuse, the interior lights (on the same fuse) and other associated electrics work properly. The second I connect the brake switch the fuse blows again. Could this be the fault of a bad brake light switch or a problem somewhere else? Seems to me there is a short somewhere in that circuit, but I am not sure where it could be since the entire harness in the car is new. Would appreciate any recommendations or advice you guys might have.

As a side note, the turn signal switch seems to have stopped working completely, not sure if the brake light issue could be connected to that problem. The turn signal switch is brand new.
 

Billccm

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I chased this symptom on a 69 coronet back in the day. It was a shorted bulb socket. The contact spring in the socket had broke into two pieces and shorted to the shell.
Troubleshooting tip: get a test lamp or a 1157 bulb and place it across the blown fuse connections. It will glow brightly as a indicator of a short. Then you can unplug or disconnect the tree of harness connections to find the shorted root.
 
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twecomm

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It's possible that a short may have developed in one of the bulbs as they have dual filaments. I have seen filaments break internally and create a short within the bulb itself. Not saying that that is the definitive problem you are having, but something to investigate. Remove the tail / turn signal lamps, both front and back and visually inspect them. Could be as simple as just needing a new lamp or socket issue as Billccm says.
 

1969VAGTX

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So I pulled the fuse that keeps blowing. Ran the test light across the connections and it glows bright, so I should interpret this as a short in the line somewhere? I certainly hope that I don't have to pull the whole harness out. Will start at the back with the tail lamps. As I mentioned, the fuse blows the second the brake lamp switch is connected. Should I safely assume that this is not an issue tied to my turn signal switch?
 

pnora

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I would pull both bulbs and see if it stops blowing the fuse. If it still blows them pull the left kick panel and unplug the rear harness. Two simple tests.
 

Ron H

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Sometimes when an electrical gremlin shows up, it can be traced back to something recently changed like other wiring work/installs, lost or poor ground, etc. Had the same issue posted by Bill and same fix. Seems odd with the brake switch. Could be bad. Assume you’re installing it with activating lights since it is off when plunger is depressed. As also posted, I’d remove the bulbs and hook up the switch to see if this blows the fuse. This is indication the switch could be bad..
 

pnora

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If it is in the bulbs the fuse should also blow with the turn signal on.
 

eldubb440

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make sure someone didnt install a wrong bulb, ie: 1156 vs 1157 into one of the sockets
 

1969VAGTX

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Did a little troubleshooting today. Disconnected the rear harness at the kick panel, and the fuse still blows when the brake light switch is connected. I believe I have isolated this to the space between the fuse box, turn signal switch and brake light switch. At least I eliminated anything at the back of the car as a culprit.
 

Ron H

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I'd be a little suspicious with the turn signal work done. If it was done? As mentioned, when doing electricals, sometimes the culprit can be linked to recent work.
 

1969VAGTX

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I'd be a little suspicious with the turn signal work done. If it was done? As mentioned, when doing electricals, sometimes the culprit can be linked to recent work.
Yeah, I have a new turn signal switch on the way. I have a suspicion that the problem is linked there somewhere. It may also be tied to that weird gap in the column between the wheel and column collar that I cannot seem to figure out. But the column will probably come out next week and be gone through again with the another new switch installed.
 

twecomm

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Was everything working properly prior to you replacing the turn signal switch ?
 

1969VAGTX

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Was everything working properly prior to you replacing the turn signal switch ?
Not exactly because I have the strange issue with how the steering wheel seats on the column. Plus during this process I discovered that the brake light switch does not make contact with the brake pedal to disengage the lights when pushed in. It's not certain that the switch is the problem, but the turn signals do not work now, so there is an issue there.
 

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