393.81
Every Bus, truck, truck tractor, and every driven motor vehicle in a driveaway-towaway operations shall be equipped with A horn and actuating elements which shall be in such condition as to give an adequate and reliable warning signal.

A- would indicate singular. You only need 1.

I agree that after reading the reg it is in the singular so means one but I've always been told that if its on your truck as original equipment it should work.

That's right. If it's on the truck, it is required to work. That also includes all fluids.
A while back, one of our drivers got an inspection, and he got a warning because the windshield washer reservoir was low.

Are you spying on me?

How did you know my washer fluid low indicator light was on?

But, I've never had a DOT EVER ask me to Wash my windows to prove I had fluid..

Just got a Level-2 "walk around" inspection done in Jefferson, SD POE I-29

He had me turn on my wipers and blow the horn. Didn't ask for two horns or to see washer fluid squirt out.

He got pulled into the rest area south of Henrietta (on hwy 287), back when they had the DOT blitz a couple months ago. He said they had him pull the hood, battery box, and had the creepers out. Got the warning on the washer fluid. I'm surprised they didn't find anything else. Bald trailer tires, trailer breaks out of adjustment.. :lol:

I always thought that if it was on the truck it had to work also but according to 393.9, that is not the case. I know this refers to lights and not horns but it applies just in the fact that we have all been told that it had to be working if on the truck and the rule plainly disputes that! The key words are "required" and "additional".




§393.9 Lamps operable, prohibition of obstructions of lamps and reflectors.

(a) All lamps required by this subpart shall be capable of being operated at all times. This paragraph shall not be construed to require that any auxiliary or additional lamp be capable of operating at all times.

So, the "factory"-required lights have to be working, but not the extra chicken lights? I always thought that all lights had to work. I didn't know that.

I remember when that light law got changed. Alot of guys were getting popped by their christmas lights and I think that one of them finally took it to court and got the rule clarified.

Washer: I've had the DOT ask "turn on your windshield wipers" about everytime a level two was performed. I've never been asked to squirt the fluid. I've always been asked to blow BOTH horns.

Regulations are fine and all, but you'll never get a big smile and a wave from a little kid for tooting your wimpy electric horn as they pass you on the highway and give the universal signal. Be sure to keep this in mind.

This is soo true, and you know-- at least for me.. there's nothing that makes a bad day better than that 1 little guy smiling after you've blown that big air horn... kinda makes YOUR day as well has putting a smile on a little one's face.

Now if just a few more drivers would just stick to blowing their horn and not throwing out their "trucker bombs"-- we might continue to be 'admired' and not looked down upon.