mystery short

[baddog8it]

A few weeks ago I replaced the turn signal assembly. All appeared well, until over a week later when I went to get off a highway exit and after tapping the brakes I found that the cruise was not disengaging - I had to disengage via the steering wheel control. Finally figured out that the number 1 fuse (brakes) was blown. I'm guessing that it has been this way since replacing the turn signal assembly, but since I don't use the cruise very often, it's symptoms did not appear.

I have replaced the fuse multiple times trying to figure out under what combination of conditions it finally blows. I'm about to get a re settable circuit breaker so that I stop burning thru fuses and stop crawling under the dash.

When it is blown, the turn signals still work normally (and when it's not blown).

It does not appear to be associated with the brake switch, turning of the steering wheel, engine running/not running, headlights. With a new fuse, the hazard lights work. There seems to be a time lag between the condition (whatever it may be) and the actual blowing of the fuse. I did get it to act funny when simultaneously using the hazards and trying the turn signals.

I'm guessing that maybe I miswired the C305 connector, or if the rotating contacts inside the steering wheel are off. I did use dielectric grease on the rotating contacts - is there maybe a low electrical leak?

I would think that if the C305 connector was miswired, I'd see some other function not working and the fuse blowing would be immediate.

I'm debating just disconnecting the C305. If the problem is here or in the steering wheel, then at least I'll have brake lights (but not horn, turn signals or cruise) until the problem is fully identified.

Any ideas?

Now that I'm thinking about it, I'll try honking my horn - see if that has any relationship to the fuse blowing.

[vjsimone]

Horn - Fuse #16

Turn Signals - Fuse #5

Speed Control - Fuse #6

Check that your Stop Lamp Switch (Brake) is not shorting to ground.

Check that your Hazzard Switch is not shorting to ground.

Check your Trailer connections.

Have you replaced your Flasher Module?

Speed Control Amplifier could be drawing to much current.

You could put in a smaller fuse to see if you can get the Brake, Hazzard or Speed Control to trip alone.

Also check for a drain on that fuse with none of the above turned on.

 

[baddog8it]

Horn - Fuse #16

Turn Signals - Fuse #5

Speed Control - Fuse #6

Check that your Stop Lamp Switch (Brake) is not shorting to ground.

Check that your Hazzard Switch is not shorting to ground.

Check your Trailer connections.

Have you replaced your Flasher Module?

Speed Control Amplifier could be drawing to much current.

You could put in a smaller fuse to see if you can get the Brake, Hazzard or Speed Control to trip alone.

Also check for a drain on that fuse with none of the above turned on.

Good food for thought. I'll give some of that a try. Thanks!

I don't think that it's the brake switch. I've jiggled wires and pump the pedal and didn't get it to short. When I did get the fuse to blow one time, there was no brake pedal involved.

I recognize that the horn and signals are on other fuses, but didn't know if maybe a miswiring or shorting within the steering contact rings could cause an overload across different circuits.

I was kind of going on the assumption that this problem is related to my most recent work that I'd done.

[baddog8it]

Good food for thought. I'll give some of that a try. Thanks!

I don't think that it's the brake switch. I've jiggled wires and pump the pedal and didn't get it to short. When I did get the fuse to blow one time, there was no brake pedal involved.

I recognize that the horn and signals are on other fuses, but didn't know if maybe a miswiring or shorting within the steering contact rings could cause an overload across different circuits.

I was kind of going on the assumption that this problem is related to my most recent work that I'd done.

Another clue. Never noticed before, but with a new fuse, the brake lights are on. No matter what I do (press brake pedal, turn on/off headlights, turn signals, hazards), they stay on.

If I turn on the hazards, they work. But if I turn on the turn signals while the hazards are on, the hazards 'freeze' on and stay on. From that point on, the hazards, when turned on, do not flash - you just see the dash indicators on solid.

It took some time, but after all of that testing, the fuse finally blew as I pulled out of the gas station.

Will check the brake switch itself later this morning, but I can't believe that this switch by itself will cause the fuse to blow.

[baddog8it]

Another clue. Never noticed before, but with a new fuse, the brake lights are on. No matter what I do (press brake pedal, turn on/off headlights, turn signals, hazards), they stay on.

If I turn on the hazards, they work. But if I turn on the turn signals while the hazards are on, the hazards 'freeze' on and stay on. From that point on, the hazards, when turned on, do not flash - you just see the dash indicators on solid.

It took some time, but after all of that testing, the fuse finally blew as I pulled out of the gas station.

Will check the brake switch itself later this morning, but I can't believe that this switch by itself will cause the fuse to blow.

Pulled the connector off of the brake switch. All appears right with the world now. Will see if it continues to behave while I purchase a new brake switch.

Something in the back of my little brain is still bugging me though...

[baddog8it]

Pulled the connector off of the brake switch. All appears right with the world now. Will see if it continues to behave while I purchase a new brake switch.

Something in the back of my little brain is still bugging me though...

So, while parked, no lights on, nothing amiss.

Started my drive to the auto parts store, and I here the snap of the fuse after about 2 minutes of driving.

This tells me that there is a leak/short thru the hazard flasher or in the wiring between the fuse the brake switch.

I then pulled the hazard flasher and reconnected the brake switch. With that combo, my brake lights are constantly on, but dim.

Next step - start pulling individual wires from the C305 connector. If I don't have hazard lights, I won't miss them much. In over 30 years of driving I've only used them a handful of times.

[vjsimone]

So, while parked, no lights on, nothing amiss.

Started my drive to the auto parts store, and I here the snap of the fuse after about 2 minutes of driving.

This tells me that there is a leak/short thru the hazard flasher or in the wiring between the fuse the brake switch.

I then pulled the hazard flasher and reconnected the brake switch. With that combo, my brake lights are constantly on, but dim.

Next step - start pulling individual wires from the C305 connector. If I don't have hazard lights, I won't miss them much. In over 30 years of driving I've only used them a handful of times.

"I then pulled the hazard flasher and reconnected the brake switch. With that combo, my brake lights are constantly on, but dim. "

So what happens when you disconnect the brake light switch?

Brake lights go out?

[vjsimone]

So, while parked, no lights on, nothing amiss.

Started my drive to the auto parts store, and I here the snap of the fuse after about 2 minutes of driving.

This tells me that there is a leak/short thru the hazard flasher or in the wiring between the fuse the brake switch.

I then pulled the hazard flasher and reconnected the brake switch. With that combo, my brake lights are constantly on, but dim.

Next step - start pulling individual wires from the C305 connector. If I don't have hazard lights, I won't miss them much. In over 30 years of driving I've only used them a handful of times.

"Started my drive to the auto parts store, and I here the snap of the fuse after about 2 minutes of driving. "

Did this happen after depressing the brake?

 

[baddog8it]

"Started my drive to the auto parts store, and I here the snap of the fuse after about 2 minutes of driving. "

Did this happen after depressing the brake?

Nope, no brake used (shouldn't have mattered anyway - brake switch was disconnected).

Yes, when brake switch connected and hazard flasher removed - brake lights on (dim).

[vjsimone]

Nope, no brake used (shouldn't have mattered anyway - brake switch was disconnected).

Yes, when brake switch connected and hazard flasher removed - brake lights on (dim).

Disconnect your brake light switch to see if your brake lights are still on.