Brake lights not working

Tiny
MADCOWSCARNIVAL
  • MEMBER
  • 1999 DODGE RAM
Electrical problem 6 cyl Four Wheel Drive Automatic 130000 miles

My brake lights quit working a few days ago. All other lights on the truck work. The cruise control works. The bulbs have been tested, they work, the brake controller (aftermarket) has been tested, it works. The brake switch was replaced twice. After that, I diagnosed the leads into the switch. There is NO constant hot into the switch (I believe there should be - pink wire w/ blue(I think) tracer). There is no power coming into the switch at all. I believe dodge sends the brake switch HOT through a multi function switch. Is there a diagram available for this that can be posted? Can the multi function switch be tested? It is a $110 part so I do not want to replace without being sure. The Chilton manual wiring schematics are worthless and very incomplete.

In addition the wiring schematic from the multi function switch to the fog lights would be appreciated, those have not functioned for several years. The lead that grounds out when activated, does not fully ground out (minimal voltage remains).

Vehicle, more specifically that above is a 1999 Ram 2500 Diesel. It is a half year vehicle in that it uses a brake switch from a 2000 Ram.
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Tuesday, January 27th, 2009 AT 10:19 AM

9 Replies

Tiny
JDL
  • EXPERT
That is ignition feed, pink wire/dark blue tracer, to the brake switch, goes hot when you turn on the key, there is also a fuse, this info says fuse c 20 amp. If there is a junction where that feed comes from, other than the ignition switch.

Here are a couple of guides and diagrams (below) that will help you get the problem fixed.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run some tests and get back to us we are interested to see what it is.
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Tuesday, January 27th, 2009 AT 10:38 AM
Tiny
MADCOWSCARNIVAL
  • MEMBER
Thanks but I need the internals of the switch and before the switch so I can check the power in and jump the switch as a test. Also, am I viewing the pictures the wrong way?

This is exactly what I'm looking for.
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Tuesday, January 27th, 2009 AT 10:45 AM
Tiny
JDL
  • EXPERT
Hello again, after my morning coffee, I think the brake lights should work, even with the key off. I looked at a couple of databases on the diesel. I think that circuit should be hot all the time. The ignition switch shouldn't have anything to do with it.

The wiring diagram me and you both looked at, does show that fuse circuit goes hot, with the key on.
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Tuesday, January 27th, 2009 AT 11:20 AM
Tiny
MADCOWSCARNIVAL
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Jdl, thanks. I will take a close look at the most recent diagram. It definitely should be hot at all times (coming into the brake light switch). I don't think its necessarily the ignition switch that's a problem, I've seen several places that the lead runs through the multi-function switch, that's what I want to jump. However, it goes through another box between the multi-function switch and brake switch. That's what I need to figure out.
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Tuesday, January 27th, 2009 AT 11:36 AM
Tiny
JDL
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/170934_better_diagram_1.jpg



Is that any better? The diagram I was looking at, I increased the magnification, before I copied, then posted. That fuse is located in the power distribution center.
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Tuesday, January 27th, 2009 AT 12:04 PM
Tiny
MADCOWSCARNIVAL
  • MEMBER
Jdl,

Could you also post that same schematic for a 2000 Dodge (blown up in two parts). Some, not all of the wire colors correspond to what I have. The stop switch is most definately from a 2000 dodge though as my truck is some mid-year hybrid.

Also, if you can, where do you get these diagrams? If it is from a technical service manual, I'll happily get one of my own.
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Tuesday, January 27th, 2009 AT 12:26 PM
Tiny
JDL
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/170934_better_better_diagram_1.jpg



I'm not sure that will help much. I was looking at a power distribution wiring diagram. There's more than one page. When I magnify a diagram, I have less of the diagram on the screen. I can only copy what the screen shows.

If your county has a large local library, they should have automotive databases, if you live in a county that they serve, some of their databases, you can access from your home computer, for free.

The database I was looking at, ebscohost database. A lot of libraries carry this database. They also carry Mitchel, but, you have to go to the library to access Mitchel.
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Tuesday, January 27th, 2009 AT 12:30 PM
Tiny
DRLEHR
  • MEMBER
I had that problem with my 2002 diesel 2500. Only the rear tail lights quit. Well The guy at sand lake repair store changed a fues and a relay under the hood. Cost me 45 bucks and it worked ok.

Not sure what fuse or relay. But it was all under the hood not in the cab.

I think the fuse was a 40 because I bought a spare and it is still there as an extra. Not quite a blade style. But a funny colored fues resembeling monopoly houses stacked ontop of each other (green) with a clear window to see the fused metal on the inside.

Sorry Im not technical about this but it fixed my problem.

Damon.
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Monday, June 1st, 2009 AT 1:11 AM
Tiny
KEN
  • ADMIN
Great addition to this thread! Please feel free to help out whenever you are on the site :)

Cheers, Ken
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Wednesday, July 5th, 2017 AT 10:23 AM

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