Cruise control, brake light and horn does not work after "stoplight on" problem

[favetita]

Cruise control, brake light and horn does not work after "stoplight on" problem

I recently had the "stoplight on" problem caused by brittle plastic knob. Pulled out the 20 amp fuse to prevent battery from draining, and car was not driven for 2 weeks. Now, after replacing the plastic knob the brake lights, horn and cruise control does not work!!!

Checked 20 amp fuse and it is good. Are there any other fuses I need to check? Nine months ago, I replaced the (36750-SE0-013) Switch Assembly, Stop & Cruise due to non working stoplight and cruise control but horn was working then. Could the stop/cruise switch assembly have gone bad so soon? Any ideas on where to start? Thanks in advance.

Wil

 

[Old Guy]

The brake lights and the horn share the #45 20 amp fuse. I suggest that you pull the fuse and confirm that it is OK by using a continuity tester to check the continuity. They can fail from stress where the fusible element connects to the spade connector and when they burn out they do not always burn in the center. If the fuse checks out, go to the sub relay box A and pull the horn relay. The service manual says the horn relay is in box A; but, the SM is not always correct because Honda moved some of the relays around. I also have a 2000 and the definitive source on relay location is the 2000 Electrical Trouble Shooting Manual. However, my manual is locked up in the car trunk and the car is locked up in secure storage so I can't reference it. Anyway, try to find the horn relay and pull it from its socket. With a voltmeter, probe the relay socket contacts in the box looking for 12 volts between two of those contacts and ground. If you don't get any voltage, then fuse #45 is bad or you have a problem in the wiring between fuse #45 and sub relay box A. If you have 12 volts at the relay contacts for the horn relay, then the horn should work and you need to go through the procedure set out in the service manual to test the horn circuit.

If the check out of the horn circuit says that you have 12 volts at the horn relay terminals, open up the trunk and engine hatch to access the 2 pin connector for the high mount brake light. The connector should have a green/white and a black wire. Separate the connector and on the body harness side (not the side going to the light), check for 12 volts on the green/ white wire. You should have nothing. Have somebody press on the brake pedal and you should get 12 volts on the green/white wire. If neither of these tests work out you need to go back and check the operation of the brake light switch as per the service manual. Check for 12 volts at the plug for the brake light.


Is there any chance that the plug for the brake light switch is not fully inserted or that the plug is inverted in the switch? The plug is keyed into a slot in the switch body so it should not be possible to invert the connector; but, if it did that would screw up both the brake lights and the cruise control. If the plug is not fully inserted, same problem. The brake light switch is actually two switches in one body (hence the 4 pins). When testing the brake light switch, go to cruise control section page 23-301 of the 1991 service manual to check both functions in the switch. The brake section of the service manual only describes the test for one of the switch functions.

 

[favetita]

Connectivity check on 20 amp fuse showed it is still good. So it is possible the brake light switch might have been loosened during the plastic knob install. I was getting ready to order a replacement switch, but will check. My mobile mechanic did not have a problem replacing the old one and brake lights worked as soon as new switch was in. I will check...hopefully I would not have to mess with the sub relay box.

Thanks for the tip.

 

[favetita]

Problem fixed. 20 amp fuse was not fully seated (duh). Noticed it was a little higher than the rest, pushed it in tight and presto. Brake lights on when they should. Thanks Prime!