Brake Lights Staying on When Parking/Headlights on

Sib

Original poster
Member
Sep 6, 2014
3,446
So today I noticed my cruise control not working so I checked fuses #14 and #17 under the rear seat and #17 was popped so replaced it. Had an issue before with my driver side LED parking/brake lights popping fuse #14 and replaced that one. Had a spare LED so I replaced the passenger side LED and fuse #17 stopped popping.

Then I noticed that when I turned on my headlights and/or parking lights my brake lights would stay on. On the way home my brake lights stayed on the entire ride home. Yes I was that guy riding my brakes the whole time :hissyfit:

Did some research and have seen other people with this problem, but most of them had their brake lights stay on even after they turned off the ignition. Also saw that there might be a cross connection somewhere. My lights did not stay on after I turned ignition off.

So first, what exactly does it mean to have a cross connection and what would I need to check in that regard?

Second, am I right in thinking it is the brake light switch under the dash?

Not really sure where to start troubleshooting.

Any ideas is appreciated. Thanks.
 

djthumper

Administrator
Nov 20, 2011
14,950
North Las Vegas
You can check the brake switch to see if that is the culprit. You should be able to reach up right above the brake pedal and find it.
 

Mounce

Member
Mar 29, 2014
13,667
Tuscaloosa, AL
Was all three brake lights on or just the two drop in LEDs? If all three, brake switch sounds plausible. If just the LEDs, :eek: sounds like this'll be fun.

If it's just the two drop-ins then try replacing one with another LED or even a bulb. Maybe some internal LED circuitry failed on them. (if they're the only ones acting wrong)
 
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Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
If it's just the 2 brake lights, you can also try dropping in filament bulbs and see if the problem goes away. If it doesn't, then you know your issue is further upstream from the bulbs. Maybe circuit board, or damaged wiring.
 

Sib

Original poster
Member
Sep 6, 2014
3,446
All 3 lights were on. I'm thinking brake light switch but I saw something about cross connection and I don't know what that could mean.

I'm going to call around at local places to see if they have any switches in stock today. It's not an expensive part.

Unless there is something else I am missing or should do...
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
So your 3 brake lights are only on when the parking lights are on, but operate normally when the parking lights are off and ignition is on? If that's the case, then I wouldn't think it's your brake switch, and you do have some sort of cross connection going on somewhere.
 

Sib

Original poster
Member
Sep 6, 2014
3,446
Correct.

I am going to pick up some regular bulbs today and replace both parking/brake lights to see if that has anything to do with it.

If that doesn't work where and how would I start checking for a cross connection? Tried searching for cross connection and not much showed up to help me understand what that is.

On the old site, there was someone that had similar issues to me but they did not post again if they ever found out what the issue was.
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Sib said:
If that doesn't work where and how would I start checking for a cross connection? Tried searching for cross connection and not much showed up to help me understand what that is.
Just have to break down the problem into steps. First, we know the 3rd brake light, and tail brake lights are different circuits. So where do those come together? We also know the parking lights are involved as the main trigger for the problem, so where do the parking light and brake circuits meet with each other?

There's probably a computer or module at/near this junction. If you were buddy buddy with a fellow member in your area, swapping modules could be a handy troubleshooting technique to rule out damaged wiring. Otherwise, you may have to break out your trusty meter, and probe wires.

Another question, if you press your brake pedal when the parking lights are off, do the front parking lights come on? Trying to see if the problem flows both ways or not. :undecided:
 
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Sib

Original poster
Member
Sep 6, 2014
3,446
When I press the brakes the parking lights do not turn on.

I pulled fuse #34 in the rear seat fuse box because I wanted to see if it the brake lights still went on when parking lights were turned on and they did not.

So am I safe to think that from the rear fuse block to the back is not the issue and it lies somewhere from the rear fuse block forward?

I tried looking at the schematics that Mooseman posted and was starting to go bonkers trying to follow everything.

Is there a module under the dash that the parking lights and brake lights tie into that I could check?

I am about to get busy at work so I will have to tackle this tonight or tomorrow when I am off.
 

Sib

Original poster
Member
Sep 6, 2014
3,446
Ok so here's an update on my siutation. First of all I was able to get it fixed.

Like I mentioned earlier, I pulled fuse #34 in the under seat fuse block to help me determine if the problem was from there to the back or from there to the front. Since the brake lights did not work, I figured it was from the fuse box forward.

So thank you Blckshdw and The_Roadie for the guidance on it being a module. When I pulled the Flasher module that The_Roadie mentioned, I checked the white wire which was in pin B that ran the Stop Lights and for some reason that wire was not seated all the way in. I was able to give it a slight tug and it just came out. So I reseated that wire/plug and everything went back to normal. Since it was only partially seated in there there must've been some disturbance and went into safe mode (meaning brake lights always on as opposed to no brake lights). I really don't know.

I am not exactly sure why it was not seated in all the way either. I don't have a sound system (other than the Bose, and I don't really consider that a sound system). I also don't think even if I had a sound system that plug would come out. All of the others were connected into place and would not budge. There was a white clip holding in the wires where the Flasher Module connects to so again, I was very confused. Also, the wires are tucked up under the dash so it's not like my foot or anything was able to catch on it. I am still confused as to why this happened.

After I got everything back working I checked my parking/brake light bulbs and I noticed that my left parking/brake light bulb was EXTREMELY hot. It looks as if it melted a little bit of the black clip that hold the bulbs into the socket. So since I was afraid of it heating up more, I just replaced my two brake lights with some standard bulbs and took both LEDs out. The passenger park/brake light socket was fine and the bulb was only slightly warm. I think that the driver side bulb had to be defective for it to heat up that much. Since my brake lights were on the entire ride home the temperature of that bulb melted the socket a little bit. The socket still works and all is back to normal.

This is the second bulb that has been bad from the ebay seller I got them from. My rear turn signal bulbs (which are the same and from the same seller) are fine, but they are not used as much as my parking/brake lights. Guess I need to save up to get a set of DEPO or IPCW LED brake lights :yes: if I want to dress up the rear.

Anyways, just wanted to say thanks for the info. Love you guys :grouphug:
 

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