Been having starting issues and conclusion the battery won't stay charged. Changed the battery and noticed wire was not connected. Ended up being the horn. And it won't blaring. I checked with a new relay and fuse. I don't think there's a security system on here like everybody talks about. I haven't tried the key 3x thing. I replaced the turn signal contact even tho it wasn't broke. When I had it all apart, I did test it and everything was fine. The horn didn't go off. I'd manually push the contact into the button and horn works as it should. Put the steering wheel all back together, horn won't stop. Thoughts? New turn signal switch assy? It has the button on it but it wasn't sticking. Im guessing it's something stupid.

 

Is it intermittent or constant? Intermittent would indicate a security related problem (verify security system by looking for an indicator light on the dash when you first turn the key on).

Will it stop if you remove the relay? If yes, a short to ground in the column wiring would be the next thing to check. If no, a short to voltage in the wiring harness between the fuse box and horn is likely.

It’s a pretty straightforward circuit.

 

[QUOTE=Gumby22;450019]Is it intermittent or constant? Intermittent would indicate a security related problem (verify security system by looking for an indicator light on the dash when you first turn the key on).

Will it stop if you remove the relay? If yes, a short to ground in the column wiring would be the next thing to check. If no, a short to voltage in the wiring harness between the fuse box and horn is likely.

It’s a pretty straightforward circuit.


I’m having a similar issue with my 03 Silverado. First sign was a dead battery and then attempted a charge. When I connected the terminals to the battery and plugged it in, the horn, park lights and low beams came on - barely- but on. Pulled the 3 relays and then the battery held an overnight charge. It would start and run but without lights or horn. I bought 3 new relays and put them in, went to reconnect the ground wire to the battery and horn, park and low beam lights all came on full blast. Only way to stop them was to pull the new relays back out. I’m stumped on what would cause those three things to act like that. Need some help or suggestions as I can’t find much online with this same set of problems.

 

[QUOTE=2003CS_Z71;477511]
No ideas on my ‘03? I haven’t been able to make any progress yet. Could this be a ground issue somewhere?

 

[QUOTE=2003CS_Z71;478213]My apologies for the delay in responding - I’m in the middle of a few home projects that take most of my free time and haven’t been able to be on the forum as much.

Please provide full truck info so I can look up the right information - it’s a 2003 Silverado (1/2 or 3/4 ton?) (LT/LS/Work truck?) with what engine and 4x4 or 4x2? Manual or automatic?

When you state the lights/horn come on, but barely, what do you mean? As in, the lights are dim and the horn is kind of “groaning” so to speak? Or are the lights flashing and the horn turning on and off?

If the latter, it’s likely a security related issue which will typically set a code in the PCM, even without a SES/CEL being on. Check for the security indicator on the dash to be flashing when this happens.

A common problem is for mice to nest in the space underneath the engine bay fuse block - remove the plastic cover from around the base of the fuse block to inspect.

I can get more specific once I have more details on your truck.