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Discussion Starter #1
My bike kept blowing fuses (ignition on but not running) but only when the reg/rect was plugged in. I removed the reg/rect and bench tested it for continuity. It passed the forward and reverse bias tests. I was also told by the bike shop that it was okay as he ran the same tests.

When I connect the black wire of the reg/rect to the neg terminal of a battery and the red to the pos it shorts (blows fuse). This is not normal, right?

What's really annoying is I bought a (cheap) replacement unit. This one is doing the same thing, although it failed the continuity test showing continuity both directions.

Should I go ahead and buy yet another one?
 

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I may be way off base but my first thought is you have a short in one of the wires you are connecting. But me and electrical stuff have a running battle.
 

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Discussion Starter #3
I may be way off base but my first thought is you have a short in one of the wires you are connecting. But me and electrical stuff have a running battle.
Thanks. That was my first thought, a bare wire or something. But even on the bench using just 2 wires it shorts too.
 

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You bike has a fuse in-line between the R/R and battery? Which bike, and got a link to the schematic?
 

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You bike has a fuse in-line between the R/R and battery? Which bike, and got a link to the schematic?
the bike is a suzuki savage. the question I'm asking is, "why is it shorting when I connect the unit's red wire to the battery pos and the unit's black to the neg?" This is basically what switching on the ignition does, completes the circuit, isn't it? Does this mean the unit is bad and needs replacing?
 

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Which year model, as the wiring changed over the years?
Is the ignition switch on or off when you connect the R/R? What fuse blows - the main 20A? Are you using a 20A fuse? From the diagrams I've found, the red wire from the R/R goes directly to two fuses, one that goes to the battery, the other to the decomp controller, and the ignition switch. So, you don't connect the R/R to the battery directly; are you connecting the R wire to the fuse, or at the connector of the R/R? Blowing the fuse between the R/R and battery would indicate the wiring to the R/R connector has been reversed, assuming the diode test was done correctly, with the R wire swapped with the B/W wire at the R/R output. Also, the ignition switch doesn't intervene in the R/R output to the battery, it connects that output to the Voltage reference input of the R/R and every other electrical circuit of the bike.

Something else to check, which shouldn't be involved with the fuse blowing but still worth checking, is whether the yellow wires into the R/R read any resistance to ground/engine. This shouldn't ground the R/R +V output and blow the fuse, but could damage the R/R when running.
 

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Discussion Starter #7
Wow. Thanks so much for the time you took to research that for me. I'm gonna take a closer look at the wiring and see what I find. It would be so nice to get it up and running again.
 

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If the R/R is connected correctly, a grounded alternator stator wouldn't cause the fuse to blow, as all the diodes point away from it.
This is a typical one:
64437
 
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