what the heck is going on here, possible wire problem?

Well, long time no post guys =] I am getting my car back out for the spring/summer finally. I am pretty excited. But anyway, this problem was happening last year, but its happening once again. Whenever i hit the brake pedal, all the interior lights dim. this includes radio, gauge lights, dome light, and so on. not only this but the temperature gauge shoots way up. when i let off the brake pedal, everything goes back to normal. the headlights dim as well. the only thing i can think of is a short. my left taillight has always been more dim than my right, and im thinking this may have something to do with it. unless its a fuse, but from what i remember last year i thought i checked all of them, i could be wrong however. i am getting my car out of storage tomorrow, and i just thought i would try to solve the problem before i switch the plates and insurance. thanks in advance, and its good to be back posting on the forums =]

double check your fuses... but it does sound like you have a short... if the fuses check out, just start checking all the wires in the affected circuits... take your time, be meticulous.

Well, long time no post guys =] I hit the brake pedal, all the interior lights dim.


So you have a short in the brake light circuit. It's quite simple. From the fuse, it goes through the brake light switch, to all three taillights and to ground.

You troubleshoot it by breaking the circuit into segments, and eliminating them one after another. Possible perpetrators:

Switch
Wiring
Lamps

Start by looking at the switch on the peddle. It's fed with one wire (White w/ Green stripe and the other [Green w/White stripe] goes to the rear. Does the switch look intact? It is at least theoretically possible it is internally shorting to ground within, but then Elvis may come back too...

Any frayed wires? Inspect and remove the lamps, one after another, testing. Same symptom? If so, it must be the switch to rear wiring.

Here is a handy tool. Next boneyard trip, get a 12v taillamp of some/any kind, in a socket with 6" wires. Now, remove the brakelight fuse & put the lamp in its place. Your maximum current will be limited by that lamp. But you can watch it while you are working....

Now step on the peddle; the lamp will be near full brightness. Wedge the peddle down/dismount the switch. Lamp still lit? Wiggle wires. [I don't know where the wiring goes in a CRX. Maybe along the driver door sill?]

When you find the short, it will go out, or if your taillights are in place, go dim. That is because your test lamp is is series with the switch and regular ones.

Bingo. Remove lamp, check the fuse size -- 15A? Reinstall.

alright i will try those. thanks.

alright i will try those. thanks.


I did not call out an obvious place -- the sockets themselves. It's quite possible the short is within one of them. I suspect you can unplug them one after another....

yeah. well, its keeps pissing me off. i get behind people and my headlights flicker and my interior lights are really dim. they are sometimes affected if i apply the brake pedal, but anyway, about the socket thing. would i be best just going to the junkyard and getting new bulb socket? how would i go about testing those bastards?

Take the bulb out and put a multimeter to both sides, with the bulb out there should be no continuity.

..they are sometimes affected if i apply the brake pedal, but anyway, about the socket thing. would i be best just going to the junkyard and getting new bulb socket? how would i go about testing those bastards?


Troubleshoot first, then start changing things. When you start changing parts willy-nilly, you make an easy problem hard.

But you have changed the story... are you saying you have issues even when you are NOT applying the brakes? That changes the whole picture!

check all your grounds, I'll bet one is loose or corroded. theres 3 or 4 of them in the engine bay.

well, it it does it when the brakes are AND arent applied. so the brakes DO have an affect on it. but everything is dim anyway. my temperature gauge sometimes shoots up, and will go back down for no reason as well. sometimes hitting the brake pedal can affect this as well.

about the grounds. i noticed in the engine bay the ground that runs on the right part of the radiator housing thing that goes onto the right of the valvecover is on, but there is 2 parts to it. only one is connected. i see where the other one needs to go, but its not connected. it is one wire, but it splits into 2 that should both connect to the valve cover, i figured if its the same wire, it shouldnt matter. it has been like this since i swapped the engine, and it was fine right after i swapped about 2 years ago, but this just started happening last summer.

there is no reasoning as to how or when the grounds will start to cause problems..my car was seriously just fine one day and the next my headlights started to dim when my sub hit hard or I touched the brakes, or signaled..it just started doing it one day out of the blue..and I drive every day. I ran all new ground wires and the problem disappeared, just like that. Definately clean, or all together change the grounds. Once I saw how cleaning them up fixed the problem, I changed all the grounds and even ran a couple extra for peace of mind

Alright. Well, where are all the grounds in the engine bay? I am going to check them.

there is a ground that mounts on the thermostat housing, one that runs from the valve cover to the front of the car above the rad, and the main ground wire from the battery...it grounds itself on the front frame and the transmission...my problem was solved after replacing the wire that connects to the valve cover, but I replaced the rest for safety..its a much talked about topic on any honda forum

i had the same problem when i swaped out the tail lights in my crx. from 88 to 90. i had to splice the wires, turned out i had a short between the wires. Did you do any splicing...?

It's nice to try to be helpful, but please check post dates before adding a response to a thread.. this one is over a year old... chances are, the problem has been fixed.

Welcome to AF.