el crapitan

yes, of course. because it's all ground switched

yorke_88

Hi, just thought I'd let you know your not alone here.

First of all what year is your car? I found this page on google because my 1991 Accord is doing the exact same thing. The parking brake/brake warning light (whose idea was it to have both of these in one light anyway) stays on dim after the handbrake is released. I must mention that for a few months prior, the light would come on full randomly (usually while driving on the horrible Australian dirt roads around here) but would go out just by wiggling the handbrake and still does this, but I don't think it's the handbrake sensor as I can't get this dim light to go out.

Just as the OP said, it fluctuates though very little (it did actually go out briefly today) however I'm not sure if it's a short/electrical fault as it appears to fade in when the ignition is on III (same as the low fuel light does, which lights dimmer sometimes when it just starts to get low). It comes on with the ignition on III but I think it's a little brighter when the engine starts. It also appeared to slightly fluctuate as the brake pedal is pressed which had got me slightly worried that it's indicating something rather serious such as a brake failure (prehaps more likely just the current from the battery). However the manual only mentions the brake fluid which is fine.

It's barely visible during the day but at night the glow is as obvious as anything. Unlike the OP however my vehicle isn't fitted with ABS. Please share your results if you can fix it . I'll have a look at the fuse box tomorrow.

el crapitan

first, you need the problem to be occuring when testing. lights on by itself? good.
because the light is ground switched, all you need to do is start disconnecting the loads in that circuit one by one until the light goes out. that brake light circuit probably feeds several other components in the vehicle. you need a thorough wiring diagram of everything that circuit feeds power to. once you've disconnected the component that turns the light off, you know that you've opened the circuit and taken away the bulbs path to ground. the problem will be either in the disconnected component, or somewhere down from that component. so you reconnect the component, and move to the next component. if you disconnect it, and the light stays on, you've just isolated the problem to being between the 2 components.

basically, all you really need to find this problem is a very detailed diagram. and the ability to read and understand that diagram. by detailed, i mean complete and equipped with component locations

and yorke, the reason circuits are laid out this way, interconnected is to save money and weight. you can not have every component operating on a separate circuit. the amount of wiring needed would be insane

yorke_88

Thanks for the reply. I do have a repair manual which I think has all the wiring info in it. I'll check it out. Makes sense haha but all the other cars we've owned have had seperate brake/handbrake lights.

el crapitan

have you tried disconnecting the park brake switch?

fcm

Ditto the above^^^ "but would go out just by wiggling the handbrake and still does this" it is the very first thing I would try, remove the console and unplug the hand brake switch. 94

PatrickGSR94

iTrader: (1)

Yeah I still don't know what's up with this. Haven't had time yet to dig behind the right side trim panel to get to the ABS unit. I also plan to check around behind the instrument cluster and wiggle some wires around for the Brake light and ABS light.

The ABS light has just been acting crazy. One day last week it didn't come on at all. Then the next morning it didn't come on, but that afternoon it did. Then for awhile it would come on after driving a couple of minutes. Then sometimes it would come on as soon as I started the car. Then this morning it came on when started the car, drove to McD's, then after that it didn't come on at all the rest of the way to work.

Thing is crazy.

yorke_88

Well I was on my way home the other day when the brake light started to come on fairly bright (not quite full voltage maybe 10-11 of 12v), got me again a bit worried it may be a genuine brake warning. However the manual only appears to indicate that this is a brake fluid warning and the fluid is fine. Anyway:

I got around to looking at the repair manual which told me the brake fluid switch and the handbrake switch both have a green/red wire. Sure enough I found both of these and under the console at the base of the handbrake lever I found a screw! No more troubles with the handbrake switch as the screw was bridging the switch.

So the handbrake light doesn't have any more trouble now, but the light is still coming on (dimly again). Unless there is a fault in the brake fluid switch I can only assume the fault lies in the ground wire as suggested above. Thanks for the replies and as long as I know its not a genuine fault I'm not too worried and will get it fixed when I can. Cheers

PatrickGSR94

iTrader: (1)

Still having problems with both the Brake light and the ABS light. Brake light typically stays on dim the whole time the car is on. ABS light usually comes on a couple minutes after I start driving, but never registers any codes. Or it comes on immediately and stays on.

Yesterday evening after work I started up the car, and NO LIGHTS! But then within seconds after starting the car, the Brake light came on, about 1/2 brightness as usual. That's really odd that it would come on like that with a delay after starting the car.

Still gotta get into the ABS harness to see if the two issues are related like I suspect.

PatrickGSR94

iTrader: (1)

Alright I finally pulled the rear interior out so I could troubleshoot the ABS control unit. Followed the procedure in the Helms for if the light stays on but doesn't register any DTC's, and everything checked out. It was basically a dead end.

Then I started reading about how the ABS works and remembered that the ABS will shut off and light come on if it detects the Brake warning lights on after 30 seconds. Some autox folks will do that trick by driving around a bit with the e-brake just barely pulled so that the ABS will turn off and won't intervene during an autoX session.

So now I'm starting to think that maybe the ABS light coming on could have something to do with the brake light getting a ground signal, even though it's a weak signal. Though that doesn't explain the few random times where I'll drive, say, all the way to work and the ABS light never comes on at all, despite the brake light staying on dimly the whole time.

Today I had both ABS Control Unit connectors pulled off, the e-brake switch disconnected, AND the brake fluid level switch disconnected. ABS light was off (obviously with the harness disconnected), but the brake light was STILL on at a dim level! WTF?!?? So the light is getting a ground connection from somewhere else. Where the heck, I have no clue. Not even sure where else to look. Might take a peek behind the gauge cluster but I'm not sure if I would be able to tell anything there.

I wish there were some sort of technology that could let me SEE which wires the electrons flowed through on their way into and out of that brake warning light.

bcd7977

Wow all this chat and no obvious solution? Remove your center console/armrest, then adjust the parking brake lever according to spec....problem solved.

PatrickGSR94

iTrader: (1)

You obviously haven't read anything. All wiring controlling the Brake light was disconnected and the light was STILL on - not at full intensity but maybe 1/2 to 2/3 brightness. Brake fluid reservoir switch, e-brake switch, and ABS control unit, all disconnected and the light was still on. It's got to be some wire somewhere shorting that's allowing the Brake light bulb to close the circuit. But figuring out which wire is the problem.

el crapitan

alright, just went through the thread again, and it doesn't appear that you'd disconnected the icu yet, as recommended. the icu sits between the bulb and all of the ground switches.
disconnect it and see if the light goes out

MikeM

Driving with the parking brake will trigger a dtc 1 parking brake/switch related. Try swapping the reservoir cap since its not an uncommon failure, especially on a car thats more than 10 years old. I didn't read all the stuff here, there way too much verbiage
.

PatrickGSR94

iTrader: (1)

It can't be the cap. I disconnected the cap wiring and the light was still on. I moved the float under the cap up and down, and when it's down the light comes on full brightness just as it should, then goes back to the dimmer state when I move the float back up.

Will check the ICU later, as now I have more pressing matters. Car died on the road yesterday and haven't fully figured that out yet, other than the #4 plug wire is dead. I made a separate topic on that.

el crapitan

i'll bet it's the icu. considering what's been checked, and where it sits in the circuit logically, it's the most plausible scenario

PatrickGSR94

iTrader: (1)

Perhaps, will check that out.

htownteg

Did you ever solve the problem? The same exact thing is happening to me right now.

Jimmy

iTrader: (5)

PLEASE tell me there is an update for this.. I am experiencing the same thing and ironically it's driving me NUTS

Jimmy

iTrader: (5)

I'm getting on ebay and ordering a new ICU asap and hoping this fixes the problem.. It's not the fluid level, it's not the bulb, it's not the adjustment. Crossing my fingers it's the ICU which kinda makes sense now.

JPhilBradley

Mine is doing this same thing (has been since about February). I haven't gotten around to addressing it yet. I'll update with what I find.

BTW- ICU stands for... Instrument Cluster Unit?

tamboo

http://www.ebay.com/itm/94-97-Acura-Integra-OEM-In-dash-fuse-box-with-fuses-ICU-integrated-control-unit-/252105539676?hash=item3ab2a9405c&vxp=mtr