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Start problem

ski-n-moto

New Member
I just put a battery tender on a EFI Fatboy. The wires were reversed at the plug when manufactured and I didn't catch it, so the polarities were wrong the first time I hooked it up. Surprisingly, the battery still fully charged when hooked up right but now the bike won't crank. It does not appear that the power is getting through. All the fuses are fine. The panel light comes on but the orange light on the panel, that you have to wait for to go out before starting, never does. The headlights don't come on when the switch is turned on, as they should. The horn and alarm work. I am thinking I blew the starter or system relay. Any ideas??
 
I am thinking I blew the starter or system relay. Any ideas??

I doubt a relay was blown. That is pretty hard to do. I know you said the fuses are fine, but it sure does sound like one is bad since the headlight won't come on.. Just curious how you checked them. Visual or with a meter.
 
I have checked the fuses visually, with a meter, and by swapping them out with a spare. I just got back from the Harley dealership. They said it should be a fuse and not a relay but all the fuses are fine. Beyond that they didn't have a clue. Anybody know if there is maybe a fuse hidden somewhere like behind the headlight or under the gauge panel?
 
I just put a battery tender on a EFI Fatboy. The wires were reversed at the plug when manufactured and I didn't catch it, so the polarities were wrong the first time I hooked it up. Surprisingly, the battery still fully charged when hooked up right but now the bike won't crank. It does not appear that the power is getting through. All the fuses are fine. The panel light comes on but the orange light on the panel, that you have to wait for to go out before starting, never does. The headlights don't come on when the switch is turned on, as they should. The horn and alarm work. I am thinking I blew the starter or system relay. Any ideas??

If you reversed polarity, the Deltran battery tender will not be damaged, but a fuse in the harness side of your battery may blow. Charging back in the correct polarity should be fine, if the fuse did not blow. I believe the HD battery tender is made by Deltran, so it should react the same.

Regarding what is blown, you should do a visual check of all the fuses followed by a DMM ($10 at Harbor Freight) ohmmeter function (non powered continuity check) for 0.00 ohms on x1 scale. If you have the service manual and know how to read schematic...specifically the relay wiring, noting the NC (normally closed) contacts for 0 ohms, the NO (normally open) contacts for 1.999 (open or infinity) and the holding coil (10 ohms or so...). Continuing on, because the headlight does not come on, or the starter, you have to troubleshoot by divide and conquer by tracing the wiring/connections at the connector terminal access points. Remember electricity functions with three rules, source (battery), path (wiring & interconnection) and destination (the load or application device). Keep us informed as to your progress.
 
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First thing came to mind when you said the engine check light did not come on when the ignition was turn on was to check the run switch,the secound was the ECM fuse but sounds like you got all that covered, there are no other fuses other then in the fuse box I know of, just a breaker under the rear fender and that would cut all power and the battery tender would never blow that. Have you tried to check for trouble codes using Speedometer Diagnostic? Can't say what would cut power to headlight and ECM, they are on different circuits but sounds like you have a open circuit somewhere, do you have tail light? I would back track where you were and what you touched while installing the battery tender just to see if something got disconnected by accident. good luck
 
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