Hi, I am working on a 03 ranger with a 4.0 and it's a 2wd. Had to have it hauled in since the fuel pump died on it. After checking the relay and the inertia switch and voltage was good at the pump I dropped the tank and swapped in a new pump and replaced the fuel filter too. It's back up and running now but the owner asked if I would check for no brake lights. It had no turn signals or brake lights but the running lights and head lights do work. Checked all fuses and fuses were good. Pulled steering column covers and found wires were pulled tight so tilted the steering wheel up and wiggled the plug around and was turning the emergency flashers on and of and nothing.

Went back to the fuse panel and a fuse had blown so I replaced it and the turn signals and emergency lights are now working. Had one bad bulb on the driver side rear so I replaced that and let it run awhile and all the flashers and turn signals are still working but no brake lights at all.

I have voltage on the brown wire at the brake light switch and I have voltage on the light green/red stripe wire. The black wire is ground I found out with a paper clip,haha and the other two should go to the brake lights I suppose. I jumped out the wires with a paper clip to put power on the other two wires and nothing happened. I am not sure if the switch is good or not but jumping out the wire's should have made something happen I think.

I am assuming the brake light wires go through the turn signal switch to cancel out the brake light's when the turn signal's are on. I'm not the best at wiring but the wiring looks to be all untouched on this truck and it still has the original radio and the trailer plug still looks to be in good condition too.

What else can I check to get the an idea if that multi function switch is bad or not. I don't mind buying parts as long as it fixes the problem!! Thanks Chad

 

The brake light on the upper cab is wired directly to the brake light switch, it is powered by a Dark Green wire spliced to the Light Green wire coming out of the brake light switch.
If this brake light comes on you have power at the switch, if not then switch is bad, bulb is bad or you don't have power at the switch.

Power for brake light switch comes from Fuse #13, 20amp, then uses a Light Green/Red stripe wire to the brake light switch
This wire and fuse are "hot at all times" so not powered by ignition switch.

Yes, the brake light power for taillights does go to multi-switch for over ride when turn signal is on, it comes into multi-switch on the above Light Green wire coming out of the brake light switch

Dark Blue/white stripe out of multi-switch is Left Turn/Stop
Brown/Yellow stripe out of multi-switch is Right Turn/Stop

At the bulb socket Left Turn/Stop will be a Light Green/Orange stripe wire
Right Turn/Stop will be an Orange/Light Blue stripe wire
So wiring changes colors going to the back of the truck, at a connector I assume but doesn't show that connector on wiring diagram.

Brown wire is the Parking lights power wire and does not pass thru multi-switch, power comes from Headlight switch
Front turn signals use different wires coming out of multi-switch, and go to Dash turn indicator and front bulbs

Trailer light wiring is fused, #3 and #7 fuses, 7.5amp, are used to pass turn/stop power to the trailer light connector, but these only pass power to connector, tail light power doesn't go thru these fuses.
So if these fuses blow only trailer lights would be effected.

 

Thanks for the info Ron!! Unfortunately I had a bad catch in my back yesterday evening that resulted in me riding the couch for the rest of the day yesterday and most of today. Best I can remember there were 5 wires on the brake light switch wire, #3 wire in the middle was hot all the time and #1 I think was hot all the time. I did look today and the cab brake light was not working either but it may have a blown bulb.

As of today I can't climb up over the utility style bed that is on it and see if it is blown or not. My lower back is a little better today but I better not push my luck.

It is a work truck so they will most likely have to use it this week and maybe next weekend I can get back to figuring this out and get this out of my way. If the multi function switch is bad how hard is it to replace and how much does it cost if I have to get one?

Thanks for the reply!! Chad