Electrical Issues

Bad Battery? Screwed up wiring?

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1957flhchop
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Electrical Issues

#1

Post by 1957flhchop »

Decided to post a general electrical thread since I figure it is entirely possibly that I will have more than one question before I'm done.

I've posted here recently regarding the chopped '73 FLH I bought in May. For better or worse, I bought it not running. Was told it ran great before it was torn apart to replace some seals but the guy's business and the comfort of a newer bike kept him from ever getting any further than putting it back together. But, I bought it for a fair bit less than I would've expected to pay for the same bike running, so...

Anyway, got all fresh fluids and a new battery. Connected the battery and had no lights. The battery was supposed to be "fully charged, ready to run." I goofed up and forgot to check the voltage before I connected it just to be sure. Hindsight and all of that. But, after it had been hooked up for a minute, the battery was getting pretty hot(more than I would have expected just from being out in the sun for 5 or 10 minutes). Also, if it is any help, upon realizing it was hot I disconnected it and checked it, 6.87v. Then after it had cooled off for a few minutes I checked it again, 9.7v.
So, my first question: Is there an easy way I can determine whether the problem is the battery(internal short) or my wiring? other than coming up with a definitely good battery to swap it for?
RooDog
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Re: Electrical Issues

#2

Post by RooDog »

You surely need 12 volts at the minimum for that bikes goodies to work.
E-start, or kick only?
Eyeball every inch of the wiring for any issues, shorts to ground, bad insulation & bare wires, loose connections, and bad grounds for any of the components and fix them.... Either charge that battery, or get a new one.
It's not even close to rocket surgery, it's just a Harley, and they hate bad grounds....
....RooDog....
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Re: Electrical Issues

#3

Post by Excalibur »

Put simply,

Charge battery, let sit overnight, then test. Absolutely ideal would be a load test.

Test wiring shorts by disconnecting a battery terminal, put a bulb between battery post and lead. If bulb glows, there is current draw somewhere. By disconnecting various wiring components, the source of short or current draw can be found.

Good luck. Hope this helps.
1957flhchop
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Re: Electrical Issues

#4

Post by 1957flhchop »

RooDog wrote: Thu Jun 23, 2022 9:16 pm You surely need 12 volts at the minimum for that bikes goodies to work.
E-start, or kick only?
Eyeball every inch of the wiring for any issues, shorts to ground, bad insulation & bare wires, loose connections, and bad grounds for any of the components and fix them.... Either charge that battery, or get a new one.
It's not even close to rocket surgery, it's just a Harley, and they hate bad grounds....
....RooDog....
Kick only. There is not much left of the original bike except the motor and transmission. Basically the goodies are just headlight, tail light, and ignition.

I asked about checking the battery first because, if it's the problem, I should be able to get a refund or get it replaced for free if I do it in the next 2 weeks.

FYI also. After the battery sat for several hours and was cooled back off it tested 11.8v I don't know a ton about electrical things, but that seems weird that the voltage keeps coming back as it sits after being hot.
1957flhchop
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Re: Electrical Issues

#5

Post by 1957flhchop »

Since I'm asking electrical questions... Any idea what is going on here? I've been trying to figure out why there is a circuit breaker on the wire that appears to be going to the key switch. I've never seen that before.
battery connections.jpg
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Andygears
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Re: Electrical Issues

#6

Post by Andygears »

Hard to tell from the one photo, but it would appear that the stock setup with a circuit breaker hanging from the positive battery terminal has been inverted and jammed into that horseshoe oil tank. Raise the battery, at least, with a block of wood or similar. All those live terminals vibrating down in there are just asking to short out.

I would get rid of or return that battery reguardless and get an AGM style. Those tiny lead acid batteries boil in a hot oil tank, leak acid and generally don’t last.

My two cents
Andygears
1957flhchop
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Re: Electrical Issues

#7

Post by 1957flhchop »

Andygears wrote: Fri Jun 24, 2022 12:37 pm Hard to tell from the one photo, but it would appear that the stock setup with a circuit breaker hanging from the positive battery terminal has been inverted and jammed into that horseshoe oil tank. Raise the battery, at least, with a block of wood or similar. All those live terminals vibrating down in there are just asking to short out.

I would get rid of or return that battery reguardless and get an AGM style. Those tiny lead acid batteries boil in a hot oil tank, leak acid and generally don’t last.

My two cents
Andygears
I was concerned about those terminals as well. So I shortened the 2 studs and put some convoluted tubing around the whole breaker so they couldn't touch anything.

FYI also, the battery I had asked about in my earlier thread was junk. I got a replacement that is still lead acid, but is already filled and sealed up so I don't have to mess with that. Just out of curiosity, I did inquire about the AGM at the parts store I usually use. They didn't even show one that was quite small enough to fit inside the space in this oil tank.

Just looked at the Amazon page for the battery I got and it says "has absorbed glass mat seperator".
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Re: Electrical Issues

#8

Post by RooDog »

Just looked at the Amazon page for the battery I got and it says "has absorbed glass mat seperator".
[/quote]

Yep, that's an AGM battery. A good thing. They can be mounted any way except up-side-down. also a good thing as you can stuff an even larger batt in the space available....
....RooDog....
Mongrel505558
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Re: Electrical Issues

#9

Post by Mongrel505558 »

For peace of mind I would rip out all the existing wiring and replace it. Solder all connectors and use heat shrink tubing. It will probably take you less time than chasing down bad wires. For kick-only it's not very difficult. I just did that for a 1968 Electra-Glide, which was much more involved, but the wiring on the bike when I got it was a mess, with multiple splices using wire nuts and electrical tape. Well worth it if you plan to ride the bike often.

Also, since it's a kick-only bike you can use a tiny battery that will fit in the oil tank with room to spare. Having a barrier of air between the battery and the hot oil tank will make the battery last longer. I use a small AGM battery used in computer UPS (uninterruptable power supplies). It's been in the bike for three years now and I recently put it on a trickle charger and the green LED was flashing, meaning it had over 80% charge, after sitting for the winter.
RooDog
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Re: Electrical Issues

#10

Post by RooDog »

AGM batts are often mistaken as Gel Cell Batteries.
Here's a little info on the two....

https://www.canbat.com/guide-agm-batter ... batteries/
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Re: Electrical Issues

#11

Post by Hogey »

RooDog wrote: Fri Jun 24, 2022 5:46 pm AGM batts are often mistaken as Gel Cell Batteries.
Here's a little info on the two....

https://www.canbat.com/guide-agm-batter ... batteries/
Thanks for that Info Roo Dog
panheadrider1961
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Re: Electrical Issues

#12

Post by panheadrider1961 »

Short stop from battery to switch same as mid 70s flu fx alternator spike or regulator fault to keep from blowing battery to short inside
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Re: Electrical Issues

#13

Post by panheadrider1961 »

Fly
panheadrider1961
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Re: Electrical Issues

#14

Post by panheadrider1961 »

Flh
1957flhchop
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Re: Electrical Issues

#15

Post by 1957flhchop »

Thanks for the encouragement everyone. Turns out that the wire the goes from the battery to the alternator had gotten pinched when the previous owner reassembled things. Corrected that and the bike fired up pretty easily. Didn't take long for a non-electrical issue to present itself though. I'll address that in another thread after I've had a chance to look things over better.
Thanks!
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