Brake Lights not working!!!!

dudeman2009 said:

I just looked it over, that page is from the factory service manual for 01 Ram's, however there appears to be a discrepancy between the wiring diagram and the diagnostics image. Pins 1 through 4 are connected to the PCM, however 1 and 2 are the brake sense circuit which are used for the abs system as well as a few other functions, and pins 3 and 4 control the cruise solenoid. Pins 5 and 6 are for the brake lamp switch, I suspect someone got confused while writing the manual.

From the wiring diagram you should have battery voltage on pin 6. If you dont, you need to either trace that back, or run a new positive lead of the same gauge.

Pin 5 leads from the brake switch to a joint connector which splits between the center stop lamp and multifunction switch. Verify that pin 5 is working by using your meter to probe for voltage on that pin with the brake pedal depressed. Optionally you can use a test light to probe pin 5, it should light up with the switch depressed.

If you have power coming from pin 5, don't goto the multi function switch just yet. You can either verify that the center lamps aren't working by testing the socket with a meter, or test lamp. Or you can begin tracing the wire coming off pin 5 for an open along the way up to the joint connector.

I highly doubt that your problem is with the multi function switch if the center lamp is non-functional. It is unlikely that two different wires have gone open at the same time.

The wire you will be tracing will run up to the left side of the instrument panel, it is a 22 pin connector with aprox. 5 open terminals. It should be right next to another joint connector, No. 7, another 22 pin connector with aprox. 4 open terminals.

You will be following the wire to that joint connector. if the wire appears good all the way to the connector you will have to check terminal 16 to ensure it hasn't been pulled out of place. You can also pull the connector and test for voltage at pin 16. If there is no battery voltage on pin 16 with the brake switch depressed but there is on pin 5 of the brake switch, replace the wire between the two.

Click to expand...

dudeman2009 said:

I just looked it over, that page is from the factory service manual for 01 Ram's, however there appears to be a discrepancy between the wiring diagram and the diagnostics image. Pins 1 through 4 are connected to the PCM, however 1 and 2 are the brake sense circuit which are used for the abs system as well as a few other functions, and pins 3 and 4 control the cruise solenoid. Pins 5 and 6 are for the brake lamp switch, I suspect someone got confused while writing the manual.

From the wiring diagram you should have battery voltage on pin 6. If you dont, you need to either trace that back, or run a new positive lead of the same gauge.

Pin 5 leads from the brake switch to a joint connector which splits between the center stop lamp and multifunction switch. Verify that pin 5 is working by using your meter to probe for voltage on that pin with the brake pedal depressed. Optionally you can use a test light to probe pin 5, it should light up with the switch depressed.

If you have power coming from pin 5, don't goto the multi function switch just yet. You can either verify that the center lamps aren't working by testing the socket with a meter, or test lamp. Or you can begin tracing the wire coming off pin 5 for an open along the way up to the joint connector.

I highly doubt that your problem is with the multi function switch if the center lamp is non-functional. It is unlikely that two different wires have gone open at the same time.

The wire you will be tracing will run up to the left side of the instrument panel, it is a 22 pin connector with aprox. 5 open terminals. It should be right next to another joint connector, No. 7, another 22 pin connector with aprox. 4 open terminals.

You will be following the wire to that joint connector. if the wire appears good all the way to the connector you will have to check terminal 16 to ensure it hasn't been pulled out of place. You can also pull the connector and test for voltage at pin 16. If there is no battery voltage on pin 16 with the brake switch depressed but there is on pin 5 of the brake switch, replace the wire between the two.

Click to expand...

MvZiC MaN said:

I believe this the 22 Pin Connector your talking about?

Click to expand...

dudeman2009 said:

Yes.

Click to expand...

MvZiC MaN said:

Alright. Made a jumper from pin 5 on the Brake switch to Pin 16 on the 22 Pin connector. I have brake lights!! Yay!!

So now i have to trace the wire back from pin 5 and replace that whole strand?

Alternately, could i Splice into pin 16 temporarily? just until i can afford to go to the auto parts store and get some automotive wire.

Click to expand...

MvZiC MaN said:

Hey all, Its probably been a few years since I've posted.
Working on my sisters 01 Ram trying to figure out why the brake lights aren't working.
so far I've pulled every fuse one by one and they are all fine.
Turn signals,Hazards,Reverse Lights, and everything else still works.
I'm thinking its the brake switch but I'm unsure how to test it.

Any info or help would be appreciated.

Click to expand...

dudeman2009 said:

This should help you troubleshoot the brake lamp switch. If the switch is good, i'll look over the wiring diagrams.

Click to expand...

trevtop1 said:

I recently was told my brake lights weren't working so i began to investigate and discovered some melted wires. Trying to trace them back, could use advice or wiring diagram before i completely destroy my brittle dash. Here's a pic, not pretty.




Sent from my LG-V700 using Tapatalk

Click to expand...