Honda CBR 300 Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
64 Posts
Discussion Starter #1 (Edited)
Hey guys,

I got my newly-functional bike registered and insured, and took it for a quick little 10 mile ride. At half way, i stopped in a parking lot...did a circle, and on my way out of the parkinglot, i noticed that my digital display had gone blank. It was definitely working fine when i entered the parking lot. Not only did the digital display go blank, but i also lost tach, turn signals, headlight, and horn. I tried turning it off and then back on again, but no change...so i just took it home. Obviously the fuel pump and spark plug are still getting power, but not much else.

I'm guessing it's just a loose connection somewhere...? where should i check first?

Also, after i got home and turned the bike off, there was a fan noise coming from the radiator area for a couple minutes. Is that typical?

Thanks!
 

·
Registered
Joined
·
64 Posts
Discussion Starter #2
I'm guessing it's just a loose connection somewhere...? where should i check first?
Welp...being the impatient person that i am, i just started taking apart the front of the bike. One side perk of this unanticipated disassembly is that i'll someday be using the footage for how-to-remove-the-upper-cowl :D. Anyhow, the 20pin connector and dust boot seemed just fine. Reading through page 21-7 and 21-8 in the factory service manual prompted me to check for voltage at the lower left black wire...came up empty, which indicated that i needed to check the fuses (duh...shoulda started there and skipped all the disassembly!)

Anyhow, the 3rd 10 amp fuse is blown, which is easy enough to replace....but i can see that the 10amp spare is missing, which makes me think this isnt the first time this fuse has failed. What might be causing my 3rd fuse to blow?

Thanks.
 

Attachments

·
Super Moderator
Joined
·
3,002 Posts
Bad voltage regulator... just an off hand guess.
 
  • Like
Reactions: lightningfrog27

·
Registered
Joined
·
358 Posts
Reg/recs can and do fail. In UK we have a company Elecrex that makes good ones, don't but a cheap Chinese one.
It is usual for the fan to run if you switch off then back on for a moment. Next time, when the fan starts, switch on the engine for a minute (or less) and you'll find the fan stops when the hot coolant is pumped away.
 

·
Registered
Joined
·
64 Posts
Discussion Starter #7
<super helpful and informative youtube video>
Thank you!!

I just inspected my regulator/recitfier:
At idle my battery voltage is around 13.6 volts, and at high revs it goes to about 14.1 volts = regulator is fine.
All diodes give me ~.45 drop when going the right direction, and open circuit when measured in the wrong direction = rectifier is fine.

I did notice that my battery voltage (with bike off) is only 12.6 volts....could be that i just need a new battery? i saw in a video once that below 12.7 volts could indicate the development of lead sulphate crystals on the electrodes...
 

·
Registered
Joined
·
64 Posts
Discussion Starter #9
12.6 is low. Try giving it a charge first and see if it holds it or get an auto electrical shop to load test it (after you've charged it).
Many electrical issues can be traced to a dud battery.
I put it on my charger (NOCO Genius model G1100), and after it got up to "100%", i disconnected and measured....I'm only getting 12.8 volts on a freshly/fully charged battery.
:crying:
Guess im buying a new battery tomorrow. Thanks for the help guys!
 
1 - 9 of 9 Posts
Top