Hello,
I have a 1988 Honda Civic that does not want to shut off when I hold my foot on the brake and turn off the ignition. Also, the brake lights (not running lights) come on every time I switch the ignition to ACC. Both problems seem to come and go. I just recently noticed today that the fuse for the brake/horn was blown but the lights are still on. Any suggestions where to start hunting? Thanks.

Check/replace the ignition switch.

Honda Civic Ignition Switch Replacement

1. Disconnect negative battery cable.
2. Remove dashboard lower cover and knee bolster.
3. Disconnect 5-P connector from under-dash fuse box and 7-P connector from main wire harness.
4. Remove steering column covers.
5. Insert key and turn it to "0".
6. Remove two screws from switch and replace.

Test all under-dash and under-hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

Interesting problem, off the top of my head I know many cars use a rod that goes from brake pedal linkage up to ignition tumbler. This is used to release the steering wheel lock when brake pedal is depressed. This rod is rubbing on a harness or damaged connection at ignition switch. If there are plastic covers below steering column you may be able to remove and observe while operating brake pedal. You may even be able to see a spark when doing this.

TX probably answered your question.
A couple of things common to this problem.
Some one may have connected the brake circuit wire on an accessory(or somewhere they are touching. On brake switch, one side is hot from brake fuse, then when you press pedal it goes through steering column to signal head, then to brake lights. Brakes go through signalhead because of the 4 way flasher circuit(constant hot).
I would guess problem near/on steering column.
The 2 wires that are making contact is your accessory wire, to the brake wire(Not from the fuse block, the side that is switched and goes to lights).
Almost sounds like some one was trying to refeed brake circuit with accessory circuit, but connected to the "switched"side of the brake switch, instead of the hot side of switch.

OK so I have now replaced the wiring harness ($71.99 OOCH!) and have not found the problem. When depressing the brake pedal and releasing the brake switch the ignition acts as if it is in the II position. When I remove the brake/horn fuse the pedal no longer switches on the ignition but all three brake lights still come on if the key is inserted and the ignition is turned to II. I am completely stumped. HELP! Thanks.

Can you unplug Signal head(Turn signal connections along column).Have you had any electrical work done on car. Radio installation?
Try turning on 4 way flashers, and then turn signals and walk around car and check bulbs, May help to reveal a signalhead problem.

No electrical work. I recently had the motor out for timing belt, water pump, clutch, seals, alternator, belts, and hoses but the car ran fine and had no problems until the last few days. The car sat for over six years, could the main relay have a stuck solenoid causing this? I unplugged the entire column and still am getting power to the ignition when I push the brake pedal. All bulbs are good and flashers work correctly.

Finally! Found the problem. There are 4 wires in a rubber housing running to the third brake light in the upper right hand corner of the hatch area. All of these wires where almost cut completely through, they obviously where making some connection when the trunk was closed but when the hatch was opened they stopped shorting and the problem went away. Thanks for everybody's help on this one. By pure dumb luck I found the short.