Everything Affected...Pressing Brakes Kills Power Weird

Ill start from the top. Owned the car for many years and i havent had any electrical problems thus far.
93 Integra B18c B16 head/ecu

The problem started at night. Headlights/Radio on. Pulling up to a stop light and pressing the brakes cause the lights to dim a bit and the motor to drop in revs to the point where the car almost died. After iI let off the brakes everthing returned to normal. This problem continued and got worse. After the brakes would kill the motor I would try and restart but nothing would happen. A single click would come from the dash and all of the Cluster lights would be dim. After turning the inigtion from off to start 20-30 times the car would finally turn over and would run fine. The problem would reappear again when the brakes were pressed. I think it had more to do with the excess load on the system. Running with the radio/fogs on would make the matter worse. And if the power windows and.or headlights were turned on it would cause the car to lose power similarly to pressing on the brake pedal.

After dealing with the issue the car finally would not engage the starter no matter how many times I turned the ignotion. I tired turning the headlights/ running lights on and I would only get faint corner markers to light up. I searched a few threads and didnt find anything that entirely matched my issues. I was under the impression that the problem would be cause by a bad ground due to the fact that everything was effected by each other.

This is where it gets weird. At this point the cluster lights would be dim when the ignition was turned. The car didnt have enough power to even move the automatic seat belts when the key was removed from the ignition. It would cause a nasty fast clicking that would come out of the ECU. I checked the ground from the battery and that seems to be fine. Also turning the key to the start position did not cause a load onto the batter/headlights either. I came across a thread that mentioned something about the ECU ground to the thermostat which seemed like it could be the problem(due to the clicking). I removed the ECU ground. Removed and cleaned battery terminals and tried to start the car with the ecu ground off. Cluster lights had full power but the car would not engage starter(no surprise there, i think) I replaced the ECU ground, igition to position 2 dash lights had full power, check engine light turned off after about 2 seconds and when I engaged the starter the car started right up! Im not sure what i thought the problem was but the car ran normal for a week… no electrical problems whatsoever!

And then it happened again. I didnt have any tools so i took off the battery cables trying to get the issue to go away. And after abouut 6-7 repeatedly removing/returning neg/pos cables the car started. Still had the issue but i got the car home. And i tried to repeat the process that got it started but that didnt solve it. And to mention when i press on the emergency flasher there is a high pitched buzzing behind the cluster… no power to the lights again. At this point im not sure if it would be a relay, the ecu, a ground… or what. Any help would be appreciated and if you’ve read down to this point i cant ask for any more… Thanks guys Im missin the teg.

My guess is you have a grounding problem, redo the main grounds, batt. cable clamp and batt. post, batt. to chassis ground, [under batt.] and chassis to engine ground, DO NOT just eyeball the grounds or just undo and reconnect, disconnect them, clean the contact surfaces and reconnect making sure they are tight. 94

Since your problem occurs when you press the brake pedal, check the wires coming out of the brake switch. You may have a bare wire causing a short. If so, it will be a matter of time before you fry your main harness and ecu. The brake switch provides about 4 signals and one is to the ecu. So get underneath the dash and trace all the wires coming out of the brake switch before it causes more damage. You may have to open up some of the loom to get to all of them. Break out a multimeter and check continuity on those wires.

[QUOTE=ng8650;2261480]Since your problem occurs when you press the brake pedal, check the wires coming out of the brake switch. You may have a bare wire causing a short. If so, it will be a matter of time before you fry your main harness and ecu. The brake switch provides about 4 signals and one is to the ecu. So get underneath the dash and trace all the wires coming out of the brake switch before it causes more damage. You may have to open up some of the loom to get to all of them. Break out a multimeter and check continuity on those wires.[/QUOTE]Say what???
A short in any brake light lead will blow the brake light fuse.

Also, what lead from the brake light switch goes to the ECU/ECM, and why would it?

Brake light switch leads will be 12V+ input and outputs to the brake lights and CC control unit if car has cruse control. 94

[QUOTE=fcm;2261992]Say what???
A short in any brake light lead will blow the brake light fuse.

Also, what lead from the brake light switch goes to the ECU/ECM, and why would it?

Brake light switch leads will be 12V+ input and outputs to the brake lights and CC control unit if car has cruse control. 94[/QUOTE]

OBD0: C10
OBD1: D2

Green wire with white stripe that goes directly from the above ecu pinout to the brake switch, no fuse. Break out your multimeter and do a continuity check to see for yourself.

sounds like your Ground

Thanks for the response guys. I am going to redo all of the grounds. I seemingly had the issue fixed for a short period of time which makes me think it is indeed a ground.

I pulled the starter and replaced the contacts in the solenoid trying to save a few bucks on a new starter. Cleaned and checked the ecu ground and battery ground which didnt “look” too bad. I couldnt find any other exposed wires or anything that looked bad in the way of wiring. I put the car back together and everything worked great! for about a week… Until the starter issue returned but i didnt have any issues with the electrical i.e. brake lights killing radio/window switch dimming lights/ headlights killing motor and everything in between. Slowly the problem began to return. My ABS pump has issues trying to prime the system (next project) so whenever the pump would start clicking it would kill the radio. The problem progressed back to where it was and now im at the point where im going to replace all of the ground wires and contacts in hopes of making some progress.

THe starter is an obvious problem but i dont think that it would be connected to any of these problems. Does anyone know how many volts i should be reading from the ignition wire to the starter? im not trusting my gauge that reads 9v from the black/white wire into the starter. Im currently using a wire to jump the solenoid to the positive cable… turns right over.

Im going to replace starter/ wires/ possible alternator early next week so i will post a follow up after that. Hopefully itll be fixed. Ive searched high and low for similar problems and i havent come across anything that fits exactly with my problem. And the solutions ive come across are everything from alternator/ headlight bulb/ wet relay/ grounds. If anyone has anything to add… GREAT!

[QUOTE=92bDA9;2265558]Im currently using a wire to jump the solenoid to the positive cable… turns right over…

Im going to replace starter…[/QUOTE]

If your starter can be jumped there is nothing wrong with it. Don’t waste money on something you don’t need. The problem is anywhere from the ignition switch to the starter motor wiring. The starter wire probably needs replaced.

[QUOTE=92bDA9;2265558]Thanks for the response guys. I am going to redo all of the grounds. I seemingly had the issue fixed for a short period of time which makes me think it is indeed a ground.

I pulled the starter and replaced the contacts in the solenoid trying to save a few bucks on a new starter. Cleaned and checked the ecu ground and battery ground which didnt “look” too bad. I couldnt find any other exposed wires or anything that looked bad in the way of wiring. I put the car back together and everything worked great! for about a week… Until the starter issue returned but i didnt have any issues with the electrical i.e. brake lights killing radio/window switch dimming lights/ headlights killing motor and everything in between. Slowly the problem began to return. My ABS pump has issues trying to prime the system (next project) so whenever the pump would start clicking it would kill the radio. The problem progressed back to where it was and now im at the point where im going to replace all of the ground wires and contacts in hopes of making some progress.

THe starter is an obvious problem but i dont think that it would be connected to any of these problems. Does anyone know how many volts i should be reading from the ignition wire to the starter? im not trusting my gauge that reads 9v from the black/white wire into the starter. Im currently using a wire to jump the solenoid to the positive cable… turns right over.

Im going to replace starter/ wires/ possible alternator early next week so i will post a follow up after that. Hopefully itll be fixed. Ive searched high and low for similar problems and i havent come across anything that fits exactly with my problem. And the solutions ive come across are everything from alternator/ headlight bulb/ wet relay/ grounds. If anyone has anything to add… GREAT![/QUOTE]

Did this fix the problem?