Jump to content

Piaa driving lights with an autotswitch popping fuses


Recommended Posts

01 R1100R Piaa 55 watt driving lights with an Autoswitch

have apparently gone to ground. Pulled the tank today and the wiring is as I installed it a year ago. No problems.

Pops the 20 amp fuse as soon as the autoswitch engages to power up the lights.

Best estimate is it is either the relay or the autoswitch.

Bet would be the autoswitch. Anyone seen an autoswitch fail in this manner?

Thanks as always,



Link to comment

You might investigate the fuse as well. It really should be a slow blow type for this application. While the lights are 110 watts, and, at the 13.2 volt system voltage, assuming the engine is running somewhere above 2K or so RPM, they will only draw 8.4 amps while running, their inrush current will be quite a bit higher than that.


I doubt it is the relay, they are too simple a beast. Easy enough to bypass the Autoswitch to check things out. You could also remove just one bulb and see if the circuit maintains with that load.

Link to comment

This is going to take some investigating! First step I'd suggest (beyond Ed's point of using a slow-blow fuse) is pull the relay. Now does it blow the fuse when you engage? If so, look toward the autorswitch. If not put the relay back in and disconnect the lights themselves (at the lights). Now does it blow? If not, look at the lights, if so, look toward the relay to lights connectivity. "Divide and conquer" is the approach!

Link to comment

Would appear to have been a loose ground at the right lamp.

Caused too much draw. Looks like Ed was right (of course) 20 amps is close to max initial draw. I'll look

into a slow blow or breaker for that app.


Thank all....

Link to comment


This topic is now archived and is closed to further replies.

  • Create New...