Intermittent Brake Warning light while driving

[Klinger74]

I've tried the search function, but no one seems to have this issue. I was driving to work this morning (about 60-65 on the highway) and my brake warning light came on for a few seconds then went out, all by itself. Those 2 seconds felt like longer, though, let me tell you. Brakes weren't applied, oil pressure was good on gauge (brake warning light seems to flicker with the oil psi light, but oil light stayed off in addition to the good gauge reading). Did this a couple more times before getting off the expressway.

Drove the rest of the way to work on side roads (about 12 miles) because the rain this morning was causing massive traffic on the expressway, and the light continued to do this intermittently. Once it came on and stayed while driving, but a touch of the brake pedal turned it off (and it stayed off for a bit). Once or twice it would flash really quick when first hitting the pedal, but I could barely catch it in those instances. No consistency in any occurrence in either situation; I could go a few times between lights with nothing, then during the next mile it would come on then go back out while cruising down the road.

Front discs (no adjustment), just readjusted the rear drums last week (light started to come on and fade out before this during apply; adjusted the brakes and that problem went away). Brakes feel fine, no different than they've been. I'm thinking one of the brake switches is starting to go? They're new (only 4k miles on them), but who knows how good they are. Or maybe a short somewhere? Just way to intermittent/random to be able to replicate the issue so far, and no other signs of brake system failure, which makes my first thought an electrical glitch.
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'74 Standard Beetle, mostly Stock 1600 DP, Manual trans

[sb001]

Yeah, if touching the brake pedal makes it go out, or makes it flicker, I would say the brake switches are suspect. What brand are they? If they are cheap FLAPS type Chinese switches those have been known to wreak havoc.
See if you can get someone to follow you around as you drive the car and watch if the brake lights flicker or do not operate correctly as well- that would ensure it is the brake switches, although being dual circuit the lights may still operate correctly while the dash light does not.
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I'm the humblest guy on this board.

1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor

[gt1953]

I too suspect the brake light switches. Intermittens are difficult to trouble shoot. I can bet you have 3 prong switches.
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Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[Abscate]

Make sure you wear safety gloves looking for your intermittens
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.ssS!

[Klinger74]

Yes, dual 3 prong switches, so the brake lights are probably still fully functional. Sorry, I forgot to mention that previously.

Unfortunately, I think the switches are the cheapies. I sold an old junk engine and set of spray-bombed bumpers to a used VW parts dealer near work. His daughter runs the Parts Place, Inc in Warren, MI, so I sold him the parts cheaper than I wanted to if he could also get me 2 new brake switches shipped to my door for free. Seemed like a conveniently good deal at the time (rather than pay for shipping on a small order). Likely they gave me the cheapest ones they had, which is another reason I suspect they're the culprit. Probably gonna order OEM ones and swap them. I guess as long as that's all it is, I don't have to panic.

Is there anywhere I should avoid for the OEM switches? Like, places that have them labeled OEM but aren't? Or I guess, who's usually safe to go to? (I'd prefer to have multiple options in case I decide to get other stuff, too). Thanks!
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'74 Standard Beetle, mostly Stock 1600 DP, Manual trans

[birddog1]

You only want FTE or ATE brand specified switches, they're as good as it gets these days. OEM only descriptions don't mean much these days with some vendors.

Bughaus is a fav retailer of mine, they sell either FTE or ATE as do other vendors.
http://www.bughaus.com/beetle42.htm

.

[Klinger74]

[ashman40]

[Klinger74]

What I meant was, like you said, when the oil light comes on, so does the brake lamp. I typically only see the brake warning light right before it stalls and the oil PSI drops off, along with the oil psi light.

However, in THIS case, the oil light stays off when the brake light comes on, leading me to believe it's something in the brake circuit. Brake pedal free play good; I fixed that when I overhauled the brake system. I don't know about the brake light coming on during start-up, as the parking brake is always set.
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'74 Standard Beetle, mostly Stock 1600 DP, Manual trans

[ashman40]

[Klinger74]

Started it with the parking brake down; brake warning came on and went out with Oil light. With the parking brake handle up while running, only the brake warning light comes on. Parking Brake switch definitely turning off with the lever down.

It hasn't come on the past few days; strange. Granted, hasn't been raining nearly as heavy as it was the 2 days the issue showed up. I'll see what happens, if it comes back on with good weather yet, or if it starts acting up again in the heavy rain. Maybe some water splashed up on the switches themselves and pooling in the terminals. Rubber connector boots are 41 years old (harness out of a '76), so they're probably not 100% water-tight anymore.
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'74 Standard Beetle, mostly Stock 1600 DP, Manual trans