How to wire a breakaway switch alarm??
Here's an interesting problem for the folks familiar with wiring challenges........from someone with skills on the mechanical side.
A few weeks ago we set up the travel trailer early in the afternoon and disconnected the truck, all as usual. About 11PM I was doing my night time check of things before going to bed and heard a hum that I traced to the brakes. Apparently I accidentally pulled the breakaway switch plunger out when I was trying to get the safety chains off the ground and the brakes had had full voltage for 11 hours. Luckily no damage that I can find.
I would like to install a horn or buzzer to warn me of this if (when) I make this same mistake again. I bought a simple back-up alarm for this purpose.
Initially I thought I could just splice this horn into the side of the breakaway switch that is energized when the plunger is pulled. However, this side of the switch is common to the wire that goes from your truck brake controller to the wheel magnets, so it is energized frequently from the other direction. IF I wire it the way I was thinking, it will beep when the plunger is pulled out, but it will also beep every time I apply the brakes when driving. That's going to be hard to explain to DW.
One solution would be a check valve (diode?) to prevent the normal brake controller voltage to come back up this wire to the switch, but I'm not sure they make diodes that strong (13V and 12 amps).
Anyone ever done a modification like this, and/or have ideas on how to wire this in so the horn is only energized when the plunger is pulled out?
Thanks.
A few weeks ago we set up the travel trailer early in the afternoon and disconnected the truck, all as usual. About 11PM I was doing my night time check of things before going to bed and heard a hum that I traced to the brakes. Apparently I accidentally pulled the breakaway switch plunger out when I was trying to get the safety chains off the ground and the brakes had had full voltage for 11 hours. Luckily no damage that I can find.
I would like to install a horn or buzzer to warn me of this if (when) I make this same mistake again. I bought a simple back-up alarm for this purpose.
Initially I thought I could just splice this horn into the side of the breakaway switch that is energized when the plunger is pulled. However, this side of the switch is common to the wire that goes from your truck brake controller to the wheel magnets, so it is energized frequently from the other direction. IF I wire it the way I was thinking, it will beep when the plunger is pulled out, but it will also beep every time I apply the brakes when driving. That's going to be hard to explain to DW.
One solution would be a check valve (diode?) to prevent the normal brake controller voltage to come back up this wire to the switch, but I'm not sure they make diodes that strong (13V and 12 amps).
Anyone ever done a modification like this, and/or have ideas on how to wire this in so the horn is only energized when the plunger is pulled out?
Thanks.
