Electrical Question
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Intermediate
Joined: May 2021
Posts: 47
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From: Wisconsin
Electrical Question
I’m working on a 1988 Sportster 1200, tracking down a no start issue. It has a brand new battery which, sitting in a cold garage reads 12.6 volts. At the main circuit breaker, with key on, voltage is 11.8 volts. The reading on the ignition circuit breaker is 11.41 volts. It seems that this voltage readings should be higher, especially at the main breaker. With these low readings, there won’t be anything neat 12 volts at the start switch or the coil. Does this sound like bad (internal corrosion) battery cables and bad ground connections? Since there is nothing between the battery and the main breaker except the wire, that seems most likely the case. Any ideas?
Stellar HDF Member
Joined: Feb 2013
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From: Dallas, Texas
I see yer in WI, it's winter, do you have it on a Battery Tender while it's parked in the garage? Ya still gotta charge a new battery before ya try to use it. IF ya don't it won't fire up due to not enough voltage or amperage. I'm in Dallas, TX and all 3 of our Harley's are pluggd in while in the garage, to maintain and extend the battery life. FYI - 12.6 vdc is a DEAD BATTERY.
Last edited by TexasScooterTrash; Feb 24, 2023 at 09:16 PM.
Stellar HDF Member
Joined: Apr 2016
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From: Masshole
Define no start. Cranks, but doesn't fire? Doesn't crank? Voltage reading are telling me your battery is junk. Need to load test to confirm tho, voltage with no load is not a valid test.
Thread Starter
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Intermediate
Joined: May 2021
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From: Wisconsin
Bike cranks just fine, but no spark at the plugs. The battery is brand new, previous battery was only a year old. I did load test it and it failed, that’s the reason for the new battery. I’m thinking I have 2 problems: a compromised ground cable and a defective start switch. A leaking front brake master cylinder flooded the start and run handlebar switches with DOT 5 brake fluid.
Thank you for your time and expertise in replying to me.
Thank you for your time and expertise in replying to me.
Thread Starter
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Intermediate
Joined: May 2021
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From: Wisconsin
Actually 12.6 volts is about 75% charged, not dead. Yes, I did charge the new battery. And yes, I keep them on a smart battery maintainer. I do not have a maintainer on this battery because it’s only 4 days old and I’m in the process of working on the bike. I do appreciate your help and insights, though. Thank you.
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Joined: Mar 2010
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From: Honah Lee
At 12.6 to the starter, that will crank it unless it drops to 9.6 while cranking witch means a worn out battery.
Disconnect battery and set your OHM meter on the low resistance setting.
Now probe at connection, the wire, the connector on the wire and the stud.
Sometimes, something that old can get corrosion where the wire goes in the connector.
You have a connection problem.
A brand new fully charged battery with bad connections is no better then a boat anchor without a rope.
Check ignition switch too.
Disconnect battery and set your OHM meter on the low resistance setting.
Now probe at connection, the wire, the connector on the wire and the stud.
Sometimes, something that old can get corrosion where the wire goes in the connector.
You have a connection problem.
A brand new fully charged battery with bad connections is no better then a boat anchor without a rope.
Check ignition switch too.
Last edited by Jackie Paper; Feb 25, 2023 at 08:36 AM.
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From: Pennsylvania
Bike cranks just fine, but no spark at the plugs. The battery is brand new, previous battery was only a year old. I did load test it and it failed, that’s the reason for the new battery. I’m thinking I have 2 problems: a compromised ground cable and a defective start switch. A leaking front brake master cylinder flooded the start and run handlebar switches with DOT 5 brake fluid.
Thank you for your time and expertise in replying to me.
Thank you for your time and expertise in replying to me.
Thread Starter
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Intermediate
Joined: May 2021
Posts: 47
Likes: 16
From: Wisconsin
Yes, bike cranks just fine. But I’m thinking the brake fluid shorted the kill switch because I have no spark at the spark plugs, no voltage at the coil. And I now know I have a sketchy ground system. I’ll have to clean up all the grounding points I can find.