Turn signals activate horn ... sometimes

[Mopar to ya]

I have a 73 Dart Sport. I just got it and it had some issues. The steering wheel was delaminating and the wood was moving under my hands, there was no horn at all and the wire was just sticking out of the wheel hub because the horn kit was missing, and the turn signals wouldn't cancel. I bought a new cancelling cam and installed it. I soldered the wires and they are insulated. I replaced the steering wheel and installed a horn kit and also replaced the horn. It all works. Two days later, coming home from work at 3am, I hit the left turn signal and the horn starts beeping in time with the flasher. The next day, it all worked fine again. Last night it started honking again, and this time I noticed the headlights seemed to dim with each flash. I am thinking a ground somewhere because if it was a short to power you would hope a fuse would blow. I have some online wiring diagrams that really suck, so I ordered some new ones. I am hoping to fix this before the weekend, however. Anyone have any ideas?

 

[cudajim]

Ok, that's a weird one but you obviously have a short between the horn wire and the turn signal wire(s). It's most likely under the steering wheel at the turn signal switch or above it. You're overlooking something there. If you really cannot find it there follow the wire bundle down the steering post and look for any nicks/shorts in the wires.

 

[Mopar to ya]

You know, I looked at all the wires because I was using my butane soldering iron and it throws off a lot of heat. I checked the immediate wires for melting. The insulation was good, but it is 38 years old and dried out. I will have to look further for cracking or splitting. I know I have to do it, but dammit! I just got a Grant steering wheel to go on straight without realigning the front end! Do you know how rare that is? Thanks for the idea!