Needing some assistance. Electrical problem

Hello everyone, I’s searched around and found some possibilities but nothing has worked. My problem is when ever I step on the brakes the headlights and instrument/clock will blink/flicker, the radio will also “blink” and then back to normal. And this will happen everytime I step on the brakes. I replaced the battery and replace the alternator which was tested/inspected at the store before purchasing. i replaced the ground wires that is in the engine bay (the one connected to the chasis and tranny, and also the one from the engine to the chasis) none of which has solved the problem. I’m getting a headache trying to figure this out. Can anybody shed some light and guidance? Before I go crazy. I have tried to solve this problem for weeks. Please help thanks!!!

Does this happen even if the car is not moving?
Does it happen every time you step on the brake?
Does it happen, [instrument/clock/radio] if only the park lights are on?
When you say “blink/flicker” do they actually go out or just dim?:hmm: 94

Does this happen even if the car is not moving?
Does it happen every time you step on the brake?
Does it happen, [instrument/clock/radio] if only the park lights are on?
When you say “blink/flicker” do they actually go out or just dim? 94

This happens when the car moves and when it isn’t moving.
This happens everytime I step on the brakes. sometimes when I turn on fogs.
It happens when the headlights are on, just park lights on, and when no lights are on.
They basically got out for the split second like it “blinked” and this would happen to the radio/instrument/clock it would “blink” the radio would not reset itself. It will continue to play where it was.

The problem is that this will happen intermittantly. Sometimes I would drive it and no problem. Drive it for awhile or even drive it one day and the lights would “blink” or radio/clock would “blink” (if the lights aren’t on) But this time it hasn’t stopped. I thought the my battery/alternator was not working correctly or that my battery is not holding a charge so I try charging my battery with a charger but the battery is full. Both the battery and alternator are new as of 2 months. Both were tested prior to install and are in excellent working condition.

Thank you for your help. Any suggestion?

That’s a tough one, as we are dealing with at least 3 different circuits…
Brake lights, fuse 37 - 20A, [hot at all times] in under hood fuse box.
Park lights, fuse 1, [1990 W/DRL] or 11 - 15A, [hot with park lights on] in under dash fuse box.
Head lights, fuses, 3&4 - 10A, [low beam] fuses 9&10 - 10A, [high beam], [hot with head light and high beam switch on] in under dash fuse box.
Radio acc., fuse 22 -10A, [hot in acc. and run] in under dash fuse box.

The only thing I can think of that may be common to all of them is the 50A main fuse, fuse 33, [hot at all times] in under hood fuse box.
I would check it, remove it, make sure terminals and mounting surfaces are clean remount it, making sure it it tightly in place, I would go the extra step and just get a new one, if it is not the problem, you have a spare main fuse.

The other possibility may be a short in the brake light circuit.
Is it only the brake lights, [stepping on brake] that 'blinks the other lights and radio, will turning on the head or park lights “blink” the radio?:dunno:94

Thanks I’ll check those. Today I noticed the “blinking” to always occur when turning on accessories as well as stepping on the brakes, such as turning on the headlights or turning on the foglights. I was just looking around and checking the connections and fuses under the driver side fuse panel. After messing around the problem seem to dissapear for now and I hope forever. I know one of those wires belongs the ignition switch. Do you think the ignition switch is going bad? Isn’t there a yellow wire that is the accessory wire that is connected to the ignition switch? What do you think? Thanks for your help!

Yes, yellow is the acc. output from the ign. switch, also check the acc. main fuse, under plastic cover, upper right side of under dash fuse box, make sure the screws are tight.:whisper: 94

Well I made sure everything is clean and on tight. I tested the main fuse (The one covered, 40amps) and its still good. Yesterday I unplug the ignition switch wires and reconnected them and so far its working fine. Fingers crossed. Thank you very much FCM for your help. Its very much appreciated.

FCM to the rescue again:salute:

So yesterday I noticed the same “blinking and flickering” as descrbed before. Then this evening @ work, my car didn’t have any power and I wasn’t able to start the car. Basically I can see a very dim (I mean barely noticable gauge lights i.e. engine, ebrake warning lights). I thought I left the headlights on but it wasn’t. So I thought I had a dead battery and that I needed a jump. After waiting for security to help (~30min) I decided to try again. Next thing I know I had power again and it started right up. No flickering/blinking lights/radio. I also noticed that my radio was not reseted but my clock was. I checked my battery connection and everything is cleaned and tightened.

So my question is: Is it the ignition switch that is causing the problem? Or is it something else.

Please help me solve this problem.


The ign. switch will have no effect on the lights, [gauge lights].
There is definitely a connection problem, you say you have checked the batt. terminals, how did you do that, by seeing if they were tight or actually removing them cleaning both the posts and the cable clamps and reconnecting?
Have you checked the chassis ground, it is located under the batt. “box”, remove batt., remove batt. “box”, remove chassis ground and clean everything, [a wire brush or sand paper works] reconnect, making sure it is tight.

Finding the cause of an intermittent problem can be difficult, your problem is a connection problem, use the cars park lights, [gauge lights] as a testing device, ideally the next time you run into the no start problem, when gauge lights are dim, but may be possible at any time, turn park lights on, then start aggressively moving harnesses, start at the under dash fuse box, grab a harness comming off the fuse box an “wiggle” it around, keep doing it, moving from one harness to another under the dash to see if you can get the park lights to cut out. [if they are on, better yet, turn on if they are out like the last time]
Do the same around the under hood fuse box, I would even start there as it seems the problem effects all electrical.:stare:94

Thanks FCM, actually last week, I cleaned and replaced the ground cable that is connected to the chasis and tranny with 4g cables. As well I clean the battery terminals and clamps. It does sound like a connection problem and it will be a pain in figure out which one it is. Just thought that there maybe something that I missed. Thank you again FCM.

BTW if it changes anything along with the gauge lights going dim and barely noticeable the clock/radio/headlights were completely dead too. Emergency lights nothing will turn on. There was a fine clicking sound coming from under the dash on the passenger by the fan. Anyways thank you and let me know if there maybe something else I should look at.

This problem is driving me nuts and I’m taking my S2k to work and don’t really want to do that ( I work 12 hour shifts)

The same goes for head lights and hazard lights are not connected through the ign. switch at all and no matter what was wrong with the ign. switch they would still work.

You are loosing power to everything, including the ign. switch, and that can only mean a main ground or a main power, and as mentioned, because it is intermittent it may be very difficult to find, so all you can do are the obvious things like making sure the ground connections are good.

Let me ask you this, did you have this problem before you did the ground upgrade, or is it something that has started happening since the upgrade?:corn:94

This problem was noticed before the upgrade.

Then I would concentrate on the 12V+ side, check the harnessing/connections around the under dash fuse box.

Have you already checked your main fuse connections?:dozing:94

Already check the main fuse connection. It has good connection and the main fuse is still good. I’ll check for loose connections around the under dash fuse box. Thanks.

Also check for loose connections at the under hood fuse box.:whisper: 94

Will do!