A sub-job completed

 
Today started with thinking about the horn circuitry. It dawned on me that I have not seen a horn relay anywhere. Looking around online didn't reveal any information whatsoever about a horn relay for a 1994 Carpenter 3800 with an International/Navistar chassis. Looking at the wire from the horn switch, it seemed very light for 15A horn units. Perhaps that's why the hillbillies put a thick, direct wire in place? The fuse for the horn is 15A and that's to the right of the steering wheel. The puzzling thing is what remains of the wiring goes straight to the horns. I shall have to ask the work mechanic if he has encountered any busses with horns wired direct to the button, without any relays.

Meanwhile I felt like working on the screws that hold down the top of the control console. Originally it was held down by sheet metal screws that had become so worn and loose that they didn't have very much effect. I'd replaced them with self-drillers but even some of those were now loose. 

Rather than using my Harbor Freight hand rivnut tool I used the older method of two wrenches, a bolt and a washer. That worked quite well.

The process is pretty straightforward. A nut is put on a bolt followed by a washer or two then the rivnut. The whole lot is put into the hole and the bolt held firmly so it cannot turn. The nut is then unscrewed. The rivnut then expands and clamps itself into the hole.

When the rivnut is in place it provides a much better way of securing things than a simple sheetmetal screw binding on thin sheetmetal. That works the first few times but eventually gives out as the hole becomes bigger. Then it's a race to use ever bigger screws.

Once the rivnuts were all in place it was really easy to fasten the top of the control panel down. That will now not shake nor rattle as it has in the past, leading to a much quieter ride.

This was not a task high on my to-do list but it was something that had been niggling me for a while. I can honestly say I detest unnecessary noise when I'm driving.

Having got this far I looked under the hood at the horn wiring. Taking off the wire nut and electrical tape the hillbillies had put on, I put spade connectors on the wire plus an extra bit of wire so that it was possible to connect the original two horn wires. That's when I realised neither of those wires came from the horn button. They headed in different directions.

I'm nowhere nearer working out what the disconnected wire is and to be honest that does not immediately interest me. I'll find that out in due course. While I was in there, I hosed out the inside of the cover over the cable junction to free it of nasty rat debris.

Connecting the two bits of grey wire and pressing the horn button, the horn relay clicked loudly but the horn sounded feebly. It sounds more like a bad horn relay to be honest. Temporarily I reconnected the red wire - so much simpler when I use the correct spade connectors! Tomorrow, weather permitting, I'll trace the wire from the inside of the bus. I'm pretty sure now that leads to a horn relay. If need be, I can use my endoscope to locate the relays but I'll bet when I find them they'll be in an obvious place!

There's no hope of asking the bus maker since Carrpenter went bus in 2001. That's 20 years ago. I doubt anybody working there even remembers that they worked there.