While I wait for a new switch, can someone wise the mysteries of the electron help me avoid a recurrence?
The situation: I bought a used R1100GS that had been equipped with a Euro switch (right hand switch featuring control over lights), a wiring harness with relay for PIAA’s (no lights or mounting included), and a 40amp relay controlling the PIAA relay. The Euro switch was re-wired for 1> lights off, 2> headlight on (high beam controlled by standard left-hand switch), 3> headlight on as #2, and driving lights slaved to high beam. I.e. when the Euro switch was in the second “on”, and the high beam was “on”, then the 40 amp relay was energized and sent current to the PIAA relay turning on the driving lights.
I wanted to add both driving and fog lights with the driving lights slaved to the high beam as before, and the fogs on with the low beam. I reasoned I could do this by replacing the 40 amp relay with a single pole, double throw relay. ‘Normal Open’ energizing the relay for the driving lights, and the ‘Normal Closed’ the relay for the fogs. Got a relay at NAPA rated 20/30amps that seemed adequate, as its purpose was to control the relays for the lights. Call this Relay 1.
I added a pair of Hella FF50 to each light circuit with each light rated at 55 watts (so 2 * 55 = 110 watts). I replaced the PIAA wiring and relay with the two Hella’s kits that featured noticeably heavier gauge wire. I left in place the wire to Relay 1’s coil (85) that was hard connected into the high beam circuit at the left switch connector; and Relay 1’s power lead (30) that was hard connected into the right switch connector getting current through “on” position #2. Those wires were 16 gauge and had been shrink wrapped together for the journey to the relay. Hey, it worked for the other guy.
Sit Lux. Great light for a couple of weeks until one day I flipped on the extra lights and had an acrid cascade of smoke billow from under the gas tank. Crap. I pulled over, checked for flames, and, after determining the problem lay in the second “on” position and disconnecting Relay 1, continued home with the regular headlight.
The aftermath: For as far as I can see around the connector (where the right hand switch plugs into the wiring harness) the insulation is bubbled on the wires providing power from the ignition switch (Green/Blue) up to the Euro switch’s “on” positions, and then back down to the connection to the power lead to Relay 1 (30). The insulation on the power lead to Relay 1 was melted from the connector to a point about half way back to the relay. Here the copper was exposed through its insulation and a layer of shrink wrap. From that spot to the relay the wire doesn’t look as if it got hot.
Being as all the damage is upstream from Relay 1, I surmise that at that halfway point the wire may have shorted after being pinched between the frame and gas tank, or at a pre-existing flex fray. Sound Right? Or am I missing something more basic? How many amps does it take to energize the coil of a relay and what wire gauge is needed? Any reason to replace the 20/30 amp relay with a 30/40?
Thanks for any help and elucidation.
The situation: I bought a used R1100GS that had been equipped with a Euro switch (right hand switch featuring control over lights), a wiring harness with relay for PIAA’s (no lights or mounting included), and a 40amp relay controlling the PIAA relay. The Euro switch was re-wired for 1> lights off, 2> headlight on (high beam controlled by standard left-hand switch), 3> headlight on as #2, and driving lights slaved to high beam. I.e. when the Euro switch was in the second “on”, and the high beam was “on”, then the 40 amp relay was energized and sent current to the PIAA relay turning on the driving lights.
I wanted to add both driving and fog lights with the driving lights slaved to the high beam as before, and the fogs on with the low beam. I reasoned I could do this by replacing the 40 amp relay with a single pole, double throw relay. ‘Normal Open’ energizing the relay for the driving lights, and the ‘Normal Closed’ the relay for the fogs. Got a relay at NAPA rated 20/30amps that seemed adequate, as its purpose was to control the relays for the lights. Call this Relay 1.
I added a pair of Hella FF50 to each light circuit with each light rated at 55 watts (so 2 * 55 = 110 watts). I replaced the PIAA wiring and relay with the two Hella’s kits that featured noticeably heavier gauge wire. I left in place the wire to Relay 1’s coil (85) that was hard connected into the high beam circuit at the left switch connector; and Relay 1’s power lead (30) that was hard connected into the right switch connector getting current through “on” position #2. Those wires were 16 gauge and had been shrink wrapped together for the journey to the relay. Hey, it worked for the other guy.
Sit Lux. Great light for a couple of weeks until one day I flipped on the extra lights and had an acrid cascade of smoke billow from under the gas tank. Crap. I pulled over, checked for flames, and, after determining the problem lay in the second “on” position and disconnecting Relay 1, continued home with the regular headlight.
The aftermath: For as far as I can see around the connector (where the right hand switch plugs into the wiring harness) the insulation is bubbled on the wires providing power from the ignition switch (Green/Blue) up to the Euro switch’s “on” positions, and then back down to the connection to the power lead to Relay 1 (30). The insulation on the power lead to Relay 1 was melted from the connector to a point about half way back to the relay. Here the copper was exposed through its insulation and a layer of shrink wrap. From that spot to the relay the wire doesn’t look as if it got hot.
Being as all the damage is upstream from Relay 1, I surmise that at that halfway point the wire may have shorted after being pinched between the frame and gas tank, or at a pre-existing flex fray. Sound Right? Or am I missing something more basic? How many amps does it take to energize the coil of a relay and what wire gauge is needed? Any reason to replace the 20/30 amp relay with a 30/40?
Thanks for any help and elucidation.
My R80 G/S 1980 had poor electrics ... but at least it was safer than these new things!