Author Topic: CB400f Blowing Main Fuse (Read 10488 times)

Stev-o · « **Reply #25 on:** March 07, 2018, 05:37:52 PM »

Had a bad feeling about this bike, sorry to here of the issue. Who sells a $4K bike w/o a battery?

Here is the type of test light you need [$6], sold all over...

https://www.amazon.com/Professional-6-12V-Circuit-Tester-Industrial/dp/B003UHNMMS

scottly · « **Reply #26 on:** March 07, 2018, 07:13:17 PM »

Quote from: jakec on March 07, 2018, 08:50:41 AM

There are 2 black wires coming from the right hand controls, one for the kill switch and one for the starter switch. Since i'm suspecting the starter switch, I should disconnect its black wire and see if the fuse (or light) still blows?

The black wire with the white stripe is the output side of the kill switch; if it were shorted, the fuse would only blow, or the test light brightly glow, when the kill switch was set to Run, unless the short is in the control itself. The solid black wire is the input. The black/red wire is the output to the headlight, unless the starter button is pressed, at which time the power is transferred from the headlight to the starter solenoid on the yellow/red wire. Try disconnecting all the wires to the right hand controls and see what happens.
PS, to judge the difference in brightness with a test light, connect the leads directly to the battery; this will be the brightness of a dead short with the test light substituting for the fuse.

jakec · « **Reply #27 on:** March 08, 2018, 09:54:39 AM »

Quote

Had a bad feeling about this bike, sorry to here of the issue. Who sells a $4K bike w/o a battery?

The previous owner definitely had this bike sitting for a long time. Everything single part of the bike is so clean like it's never been outside. Then there are small clues like the petcock, which was really gummed up with varnish. He probably stored it without a battery because he didn't feel like buying a new one. and It did technically come with one... he shipped the battery separately with no acid

Anyways, I was able to isolate the short last night, I disconnected the black wire from the starter button and the fuse stopped popping. Instrument lights come on fine now. Brake light and switches work good.

However the headlight (and everything controlled on the left side) was not lighting up. I'm not sure if the headlight is broken or not, I fiexd the prongs with epoxy, but I was showing 0.00 volts on the headlight dongle with the key on.

I tested the battery terminals and it was only showing 10.38 volts. First charge ever and it had been sitting for about a week so I am charging it now. Last I checked it was showing 14.8 volts. Hoping all the other non working parts (blinkers, horn, headlight) come on with a full battery.

As for the starter switch, I supposed I will get it off and see if I can't rebuild it and find out why it's shorting. Any suggestions?

P.S. dont feel sorry for me, I feel like this is a good way to get acquainted with the new bike. At first I was afraid to touch it (don't feel that way on my other bikes) but that feeling is slowly melting away.

scottly · « **Reply #28 on:** March 08, 2018, 10:11:57 AM »

Quote from: jakec on March 08, 2018, 09:54:39 AM

Anyways, I was able to isolate the short last night, I disconnected the black wire from the starter button and the fuse stopped popping. Instrument lights come on fine now. Brake light and switches work good.

However the headlight (and everything controlled on the left side) was not lighting up.

The black wire supplies power to the headlight, so with it disconnected the headlight won't work.

jakec · « **Reply #29 on:** March 08, 2018, 10:20:23 AM »

Disconnecting the black wire that goes to the right hand control (start button) will stop the headlight from working?? Jeez! Ok looks like I need to figure out why the switch is shorting asap.

scottly · « **Reply #30 on:** March 08, 2018, 10:45:01 AM »

Disconnect the other wires from the control, and plug the black wire in. If the fuse blows, the short is in the control, possibly shorting to the handlebar.

jakec · « **Reply #31 on:** March 09, 2018, 08:33:49 AM »

Haven't had time to work on the bike yet, but I have to remove the wheels tonight so I can take them to the tire place to get my new tires installed. Will have to revisit this on Saturday or Sunday.

Stev-o · « **Reply #32 on:** March 09, 2018, 08:39:25 AM »

Quote from: jakec on March 08, 2018, 09:54:39 AM

Quote
Had a bad feeling about this bike, sorry to here of the issue. Who sells a $4K bike w/o a battery?

P.S. dont feel sorry for me

It's not that I feel sorry for you but I dont like to see buyers taken for a ride.
For what you paid for that bike, it should have been a running, no issue bike.
Dont ever believe a seller's stories!

jakec · « **Reply #33 on:** March 09, 2018, 09:47:52 AM »

Quote

For what you paid for that bike, it should have been a running, no issue bike.

Yeah, luckily it's not costing me any money yet, just time.

jakec · « **Reply #34 on:** March 10, 2018, 08:10:14 PM »

Hey guys finally got to work on the bike today.

Since you guys deserve some pics by now here you go, new side covers:

Anyways the wheels are off for tire replacement right now. I was able to determine that the new battery is acting up and was causing everything to not work. After charging it a second time it's still showing 10.3 volts. I'm charging it again now. Does anyone know what could be causing that? The initial short out? overfilling acid (it's a bit above the lines)?

I put in the battery from my CL 175 in (showing 12.5 volts). Everything works now. I have the right side control opened up and dangling off of the bar and no shorts.

I wrapped the bar in some electrical tape, and then put the controls back on, and it shorted again. So I am guessing it's shorting against the bar. Any ideas other than more electrical tape?

Stev-o · « **Reply #35 on:** March 10, 2018, 08:18:42 PM »

Is the battery new? If yes, could be defective. If no, get a new one, I like AGM, no chance of spilled acid.

BTW - new side overs look great!

Flyin900 · « **Reply #36 on:** March 10, 2018, 08:26:48 PM »

You may have a problem with the switch internals that could be grounding on the handlebars. The kill switch section is high up in the switch and too far away from the bars. So the push button starter part could be grounding out against the bars as its back end where the wires are located would be the closest to short out.
There maybe a short in the wiring that is also causing the issue somewhere close to the area where the wires go down into the cutout for the handlebars. This assumes the wiring is routed down through the handlebars internally and it could be shorted in that area too.

Sounds like you have the area pin pointed better now and just a check of the wiring should reveal the issue. It also sounds like that battery is pooched and could have a short in one of the cells. If you can't get 12.6 V + after charging then something is wrong with the battery.

Side covers look great and did you buy them finished or have them sprayed the Varnish Blue?

jakec · « **Reply #37 on:** March 10, 2018, 08:27:46 PM »

The battery was new, shipped to me with no acid and I filled it. I probably overfilled it a bit as all the cells are a bit over the top line. Is that bad?

Edit: yeah a friend of mine suggested I shorted a cell the first time the bike blew the #$%* out of the main fuse. I'm 99% sure that the starter push switch is the short and it is against the bar. When the control is on the bar and the black wire to the switch is disconnected, no short. When it's all hooked up but dangling, no short.

I had a problem like this where the horn was shorting on the bar of my CL and the horn would honk constantly when the key was on. I just wrapped the bar in tape and that fixed the problem.

Flyin900 · « **Reply #38 on:** March 10, 2018, 08:31:35 PM »

No not an issue with a slight overfill, yet it could have been booted around in transit and a cell or section is no good internally even though it is brand new.

jakec · « **Reply #39 on:** March 10, 2018, 08:48:38 PM »

Hm. Ok. So I am charging it now. Do you think that if it's not charging above 10.3 now it never will? The battery was included in the sale so at this point I am only in it for $5 in acid. I can buy a new battery if needed.

scottly · « **Reply #40 on:** March 10, 2018, 08:54:15 PM »

Is 10.3 the voltage at the battery while it's on the charger? What type of charger are you using? Typical "tender" type chargers are limited in current output, and may take a very long time to bring a discharged battery's voltage up to 14.5V.

jakec · « **Reply #41 on:** March 10, 2018, 08:58:51 PM »

Terminals show 14.6 when it's plugged into the tender. When its unplugged it shows 10.3

scottly · « **Reply #42 on:** March 10, 2018, 09:08:57 PM »

Sounds like the battery is toast.

BTW, blowing the fuse shouldn't have killed a cell; it's job is to sacrifice it's life to protect the battery and wiring by blowing at a safe level of current.

strynboen · « **Reply #43 on:** March 11, 2018, 03:20:56 AM »

you are absolut shure you not have reversed the polarity on the battery..

there is reversed types vho had the batery poles reversed..and put on the tharger from total new,,you can fill it backvers...and then the diodes in the bike gets reversed voltage and blow up..or shorten aut..
so thek carefull the battery poles ..and marking..and test for positive ..are positive..
think a reversed battery dont get full voltage..so 10 volt can be a varning somthing are vrong

Stev-o · « **Reply #44 on:** March 11, 2018, 06:50:36 AM »

+1 battery is toast. If the R control is bad, either repair the short or replace the control.
Tape is just a temp fix and could come back to bite you at a bad time.

FuZZie · « **Reply #45 on:** March 11, 2018, 06:54:34 AM »

Quote

I was able to determine that the new battery is acting up and was causing everything to not work. After charging it a second time it's still showing 10.3 volts. I'm charging it again now. Does anyone know what could be causing that? The initial short out? overfilling acid (it's a bit above the lines)?

They are usually made of 6 cells around 2.1v each, so math suggests one bad cell. Possibly a warped plate if I had to guess.

jakec · « **Reply #46 on:** March 11, 2018, 10:36:23 AM »

Quote from: strynboen on March 11, 2018, 03:20:56 AM

you are absolut shure you not have reversed the polarity on the battery.

The battery has big + and - symbols on it that I've been hooking up with red and black, respectively.

Looks like its battery time.

How should I go about repairing the short? If you look at the initial post on this thread the black wire has a bit of exposed copper and the yellow/red wire next to it has a dab of solder. I think one or both could be touching the bar when it's installed. A mechanic friend of mine said to put some liquid tape on the whole mess and call it good.

Flyin900 · « **Reply #47 on:** March 11, 2018, 10:58:51 AM »

That is a good option and you can usually get that product at an automotive store. Did you check where the wiring goes down into the cutout in the handlebars for any frayed wiring in that area?

jakec · « **Reply #48 on:** March 11, 2018, 04:13:36 PM »

Ok, I will pick up some liquid tape, hopefully tonight. My friend says he will sell me his antigravity battery for $80. So I am considering that. $120 new. He has only charged it like 3 cycles or less.

The bad battery was showing 11.6 volts today when I took it off the charger so it may be improving.

jakec · « **Reply #49 on:** March 11, 2018, 08:51:25 PM »

Liquid tape is curing now. I very generously covered the exposed area so I am thinking this will be a good solution.

In the mean time I am trying to remove the decals from the sides of my tank. They are pretty baked on there and will only come off in little flakes. This is while using the hair dryer.

At this rate I think it would take me a couple days to get them off. However I'm tired so I stopped the night after getting about 10% off of one of the H's and one of the A's in HONDA.

I have the decal that I'm working on soaking in some wd-40 for now to see if that can soften it up any for tomorrow.

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Author Topic: CB400f Blowing Main Fuse (Read 10488 times)