Yikes - no rear brake lights!!! Rear tail lights work in terms of turn signal and nigh lights but do not work when stopping. Third brake light also not working.

Steps taken so far:

Checked/replaced all bulbs.
Checked fuses and relay under hood.
Replaced brake pedal switch.

No results so far and looking for help as we have sidelined the van to avoid getting into rear end collision.
Appreciate any advice or wiring diagrams or suggestion.

 

i know you checked fuses and all.. but replace fuse 26 in your fusebox .. it is for the brake lights.. if the center light is out along with all of them.. thats all it can be.. to test this theory tho.. get a test light.. hook the clip to the bolt that bolts the seat down. (good ground) .. then put the tip of the test light on the GRAY/RED wire.. if it lights up.. the fuse is good.. if it dont.. the switch isnt getting power.. if the switch is NOT getting power.. do the same on the fuse box.. make sure there is power on BOTH sides of fuse 26 when it is plugged in

 

Thanks for the tip - checked it out but looks like there are brake light fuses, EBL (electronic Brake light) fuse and EBL relay - nothing labeled fuse #26 for the 2005 model.Alllook good.

Additional info -
Under the hood:
1)There is power to both ends of the brake light fuse
2)There is no power to either end of the large EBL fuse
3) The EBL relay has power on 2 of the 4 leads (as expected I believe)
4) I rotated the fuse box assembly out based on the hinge (after taking the battery out for clearance) and inspected the wiring, and it looked in good condition

Under the driver side panels:
1) The brake switch wiring has 6 wires that are paired where the switch connectseach pair for 3 connections when the brake pedal is pressed. The first2 pairs havea hot 12V within is pair and whenthe brake pedal is pressed, make 2 connections - I can hear the steering column shifter click with thebrake press.The lastpair has no power on any of the leads. One of the wires is Grey/Red in color.

Any suggestions? Appreciate any help.

 

look for the white/tan wire coming out of the switch.. does it have power when the pedal is pressed? im guessing no it doesnt.. the way its wired it comes out of the switch.. then splits off.. one side goes to the center brake light.. and the other goes to the 'integrated power module' .. now if your center light works.. then we have to go the other way with it.. but im betting its your switch

 

Replaced $15 brake switch as a quick hit but no luck. Gonna look at the IPM and the whie/tan wire you suggested.

 

Update - Problemwithno power to the Grey/Red and White/Tan wire on the side of thebrake pedal switch. Both wires register zero volts. I ran 12 volts to the white/tan wire and got brake lights, ruling out any shorts from the back of the van to the brake switch.

Problem isolation - need to restore 12 volts back to the one of those wires correctly which probably means the problem is between the IPM leading up to the break switch wiring. This would sound like a fuse or relay issue but they all look good. If so, then it's the wiring between the IPM and the swithch unless there is anoter piece within that path.Does the BCM or EBL do anything here or any othersystems to rule out?Any additional suggestions or wiring diagrams available?

Good troubleshooting and process of elimination with the help of dishdude2k. Almost there and would like to avoid running a separate line and fuse to the brake switch as that will only be long term trouble.

 

OK - ruling out EBL as I have learned that this is the Electric Back Light which is the rear glass defroster and nothing to do with the brake lights.........................Still no progress on the potential short vs. mystery failed component vs. other on the brake light issue.

Given that the fuse under the hood is good and has power, that would further isolate the problem - power leaving the IPM going through the firewall into the area under the dash - does this wire connect directly to the brake switch which would mean a short or does it plug into the computer or BCM or something that might be loose or failed? Diagram would be helpful to furhter isolate but I would think this would be a real simple circuit not requiring the added stuff....

 

In review, I am leading to the following conclusion (other than a short between theIPM and the brake switch) -This sounds like a real dangerous glitch with the BCM where it goes out and you don't find out until someone tells you or someone rear ends your car....

Troubleshootingsummary - I replaced the brake switch (switch under the brake pedal that has 6 wires) which was only $15 but this did not do it. I checked the wires from back of the van to the steering column and all OK. fuses were all OK and relays so the problem appears to point to the IPM (integrated power module) which is the box under the hood with the fuses/relays that the battery has a direct connection into. Since the fuse is OK and I checked under the IPM for any disconnected wiring harness plugs, I then suspect the wires that travel back through the firewall into the driver side area. These wires usually don't short out unless in an accident so this can be ruled out. As a test, adding separate power to the white/tan wire on the brake switch lights up the rear brake lights, ruling out the middle to back half of the car as being an issue of a short (although this would work as a interim solution, I would not recommend as it might bypass someof the logic and may create other problems (so I do not recommend) and must be fused to avoid the wiring from melting down, etc. but is a good troubleshootingverification step with caution). This all leaves the problem isolated to power from the IPM to the brake switch. Since I replaced the brake switch, this narrows down the problem to the only item left in between the brake switch and good working fuse in the IPM -our good friend, the BCM.... My van 2005 is out of warranty and hope it is something simple like the dealer resetting the BCM but will find out soon...........note that this is not a good or safe design...given no warning that the lights are out.

Regarding the no power on the EBL fuse which I also havethoughtwas brake related and now understand it to be the rear window "electric back light", I bet it has power once the rear defroster switch is turned on which will energize the EBL relay and then the power to the 40A fuse. I will test this tomorrow and is probably a correct assumption.

Thing to find out - how much a dealer will charge for a reset or replacement of a BCM out of warranty...If the latter, I may need to consider a junkyard BCM or the work around.....Also, minor possibility of a short but I highly doubt it..... Hope this was helpful to others on the forum. Hope to find out the dealer impact unless a local shop with a computer can do something.... Any other suggestions???? Help

 

ok... your wiring is as follows.. and yes.. i looked at a schematic.... 1. BRAKE FUSE... 2. BRAKE SWITCH... 3. WIRE COMES OFF THE SWITCH AND SPLITS.. ONE GOES TO THE 3RD BRAKE LIGHT AND ONE GOES TO THE IPM ... 4 THE IPM DOES ALL THE WORK FOR THE BRAKE/TAIL/TURN ON THE RIGHT AND LEFT....... now... picture this in mind... if the 3rd brake light doesnt work.. its NOT the IPM.. all it can be is that brake switch... if you have power going TO the switch but not coming OUT OF the switch when the pedal is pressed.. its a bad switch.. looks like you were the lucky winner in getting a bad switch... and for 15 bucks it sounds like you got one from a junkyard.. or aftermarket... might want to try another switch... because thats what it looks to be

 

Will take you advice and try again but note that the switch was new from the Dodge Dealer and that it has 6 wires that the switch connects via 3 contacts separately. In other words, the first pair ofwires,the second pair andthe third pairof wires are connected as separate pairs when the foot pedal engages. The first pair has one wire with 12V, the second pair has one wire with 12V and the third pair (the key white/tan andgray/red)does not have any power in the two wires thus when the switch is pressed, nothing happens for that circuit. When I introduce a separate 12V to the one of the wires, the brake lights work. This is why I am ruling out the brake switch. I would like to rule out the BCM if that is in the path.

Appreciate yoursuggestionsand will try again.