i changed the little sensor and the lights still dont work i tried changing the bulbs and well no luck on that either can someone tell me what can be wrong with this ?....i dont want to get another ticket.

 

Did you check all of your fuses? I am guessing the sensor you replaced was the one on the peddle?

 

STOP fuse.

You know on a series four car if that STOP fuse is good if you HORN honks. Fed off the same fuse. So if this car is series four, honk the horn. Hopefully the horn worked prior to your current problem.

Actually on a series five the horn is also powered by the STOP fuse.

 

If the fuse doesn't work, then it might be time to break out the soldering iron. The solder joints on S4s (and I assume you have an S4) go "cold" over time. In other words, the solder joints have gone bad on the circuit board that controls the brake lights.

 

Sad to say but that's true about the CPU. If he horn honks, then you know the 20a fuse is good for the stop lights, but don't know if the CPU is good or if it's solder joints are good or bad.

So if the horn works, but the stop lights don't, do this: pull the four wire plug off the CPU. Get a piece of wire and bare each end. Put one end in the socket of the PLUG where there is a W/G or white/green wire if you will. Put the other end of your new wire into the socket where the G wire is or Green wire if you will.

Now step on the pedal. Stop lights will work if the wiring outside the CPU is good. So if they light up, then you KNOW the CPU is the bad actor.

 

wait wait. do your tail lights turn on when you step on the breaks, or do the rear tails not turn on when you pop the head lights?

 

I'm gonna be PISSED if he's not talking about the stop lights.

 

He said brake lights, hope that is what he ment. Do s4 have more problems with the soldered joints going bad than a s5?

 

I've already resoldered the brake light relay, horn relay, windshield wiper switch ICB (with new relays from Icemark's old site), and 2 Logicons for my S4. Yeah, S4s had some serious soldering issues.

 

yeah i was talking about the break lights my parking lights work fine.....it is a series 4...now i looked at the fuse and the fuse is still good but neither my horn or my tail lights worked although when i press the horn i hear a clicking noise around the fuse box area by the clutch pedal im guessing is the relay right? soo i guess i have to go to the cpu for this one

 

where is the cpu by the way

 

CPU is near your left foot.

When you honk the horn and only hear a click, that click is the alternator relay inside the CPU. The gnd signal from the horn button to the alt relay inside the CPU is working. It's just the output from the relay to the horns themselves that is in question.

This means your Stop fuse is indeed good.

Horn might not actuially honk for a variety of reasons. Like the horns are disconnected from the harness. OR cold solder joint on the CPU where the output wire for the horn is. You MIGHT hold the horn button down, and at the same time wiggle the wires on the CPU to see if that will make it work. Do that after you make sure the horns are connected to the harness.

 

so that means that i have to do what HAILERS said in order to get my break lights to work right?

 

You could buy a CIRCUIT board to replace the bad one in the CPU. From MAZDATRIX.COM

You could by a used CPU for the car.

You could first PROVE the CPU is bad by removing the elect plug I mentioned above in another post, and getting a piece of elecrical wire about three/four inches long, and strip the insulation back about a inch on each end so the bare wire shows. The stick one end of that wire in one of the sockets I mentioed earlier and the other end of your wire into the other socket I mentioned earlier. Then step on the brake pedal and see if the brake lights come on or not.

IF the lights come on, the the CPU is the problem. Buy a used one..........or replace the circuit board in the CPU..........or reflow the solder at the blade connectors on the CPU.......or buy a used one .

 

broken wire from behind pedal switch to lights in back.. thats what mine was. if running lights on then that would be my guess

 

lol

 

thanks HAILERS you were right i did the bridge and my break lights do work i need a cpu haha now i wont get another ticket... haha is it ok to keep bridge till i get another cpu?

 

I'd say yes to that. I forget what else might go thru that plug of the ECU right now. I think the only thing you'd miss, is if a brake light bulb went out, you would not get the red light in the Warning Cluster to come on showing the fault.

In fact I'd just leave the jumper in and have at it. Hurts nothing til you get around to fixing it someday. Problably a cold solder joint at the pins that the plug mates with. Refolw the solder someday.

Oh heck. If that ever happens on my car I'd just jumper the two wires and leave it like that. I've no time to fool with a junk CPU board. Hurts not a thing as long as you know the jumper is going to stay in the plug.