OK I need your help guys. I've searched and found nothing pertaining to what my problem is.

Here goes...everytime I tap on the brake pedal or just brake my voltage will drop about a volt or two and my radio will turn off then back on (Like a quick glitch) but will not reset my radio settings. I checked the room fuse and it is okay along with other fuses. Everything else seems to work normally(lights, clock, etc.). Something seems intermitent because it will do it once in awhile. It's been going on for three days now. I think I have a short somewhere but have no idea.

I checked my battery and alternator with a DVM and it all looks normall. I have a Red Top Optima battery about two years old and an FD alternator that is about a year old. It's a 91 NA vert. Everything else is stock. Can anyone help me out.

Another thing....this happened about a month ago for two days then it went away. Now it's happening again.

 

it's some electrical glitch. Make sure that when you press the brake pedal you are not moving or coming into contact with any other wires.

 

thanks....I'll check the brake switch and the proximity....

 

I've checked all wires and connection and see nothing. Now I have another problem. My battery is dead. Nothing works now! What Gives!!!!

Anymore advice!!!

 

Check to make sure the plug on top of the alternator is not damaged and plugged in all the way. I'm guessing it's either wiring or your alt.

 

Either a bad connection/ground some where or the alternator.

Check your batteries terminals to make sure they aren't corroded into a bad connection.

When ever my radio does that I know the alt is going bad.

 

Check the wires and bulbs for your taillights, a short or a ground there could cause the problem.

 

We'll I had to jump start my car at work to go home and there is still some glitches driving home. I checked all connections at the alternator and also checked the bateery terminal and I don't see anything wrong.

Gene I will check the bulb sockets to see any bad connections. I forgot that those may cause problems too. Thanks for the advice....

 

Do you guys think a bad battery cell will cause this to happen. I know that the lights will dimm when you apply a load but this is different. It feels like a short some how,

 

Bad alt.

What is the voltage when driving and at idle. It should be above 13.5 at all times even at a light with your foot on the brake.

The line between the 12 and 16 is 14 volts. the needle in the gauge should be touching that line if the alternator is working correctly.

 

The voltage is about 13.5V when driving at constant speed with lights on. It's right on the line or just a tad above it. checked with a DVM too and I got 13.5V. It will touch the line if I apply the brakes like you said.

 

same problem here, happens less though since i removed the 10" sub and amp. when i hit the brakes stuff dims and every now and then the radio (head unit and speakers) resets.

 

Did you ever fix the problem. Mine doesn't really dim out. It feels like a quick off then on really fast, like a fraction of a second (quick pulse). Its set at 13.5V but when I tap on the pedal it goes down real quick like a spike to 12.5V then back to 13.5V. Very wierd. I'm gonna check all the bulbs and sockets tomorrow and will let you guys know.

Thanks everyone for your help...

 

Thats pretty low for a FD alt. While driving (above 2000 rpm) you should have 14.4- 14.5 volts.

Is the alt wired correctly??? Doesn't sound like it or it is a bad alt.

13.5 is the bare minimum to charge the battery.

 

Icemark...I use to have above 14V before and I have seen it higher at warm up stage. It was a little scary to see but read that it is normall with FD alt. Now I'm seeing 13.5V . Is my alt. bad? I will test the alt. tomorrow again and thoroughly check it for flaws. But I think something is drawing the current down somehow. Like a short...I will also check bulb sockets too

 

I doubt a short, but suspect a mis-wired alt, or an old alt.

Shorts happen warm or cold