Battery warning Light

[nascarnutt]

My Battery warning light came on last week. I checked the water level which was fine. I tred the fix using the poor man tips, with the resistor. I tried both recommended resistors with no luck, anybody have any other ideas other than to replace the sensor?

[Black Owl]

Duct tape (for our Canadian members that's Duck Tape )

[GeorgeS]

After you hook the modified resistor ( in place of the sensor ) and hook the new resistor to " Switched " 12 V source, then measure the voltage to grd on the output side of the new resistor, you should read about 3 to 5 volts. This voltage is whats seen at the input to the CMU.

If thats OK, follow the wire thru a Plug that goes to the CMU. might be an open connection, or bad connection in that plug.

 

If thats OK, then you might have to open up the Instrument panel and do some resoldering. Or, just clean connections inside the instrument panel.

[Monsta]

Admittedly I know nothing about the older Ventures but what would stop a fella from checking to make sure the battery is good and that the charging system is good prior replacing sensors? Is this a known problem for those bikes?

[Thom]

it is not a voltage or amp senser , it is a acid level senser and you have to buy a yamaha batt. to use it

[cmiles3]

Double check the electrolyte level. It doesn't take much to set off the warning light. Thought I had mine full when checking through the plugs, but one cell was a little low. Had to pull the battery out to see it, but once I topped it off, the red light was gone.

[Black Owl]

Have you checked to make sure you have the resistor wired in correctly? Just a thought.......

[nascarnutt]

I thought I had, but I'm not 100% sure at this point. I found on the old sensor the resistor is broken and I can't read the color code any Ideas

[GeorgeS]

2.2K ohm, ( 2,200 ohm resistor, ) 1/2 Watt, avialable at Radio Shack, or any electronic Supply outlet.

 

Simply cut off the old sensor, Solder the resistor to where you cut it off. Solder a new length of wire to other end of NEW resitor, Then Cover the Entire new Resistor, and solder joints with Heat Shrink tubeing ( avialable at any auto parts store ).

 

Now Hook the new Pigtail, from your new resistor, to a " Switched " 12 volt source.

 

--- Be sure to Use Rosin Core Solder ---

[FozzyUSN]

I just ran into this same problem. Battery light would come on and stay. I had the battery checked (GOOD) and had the charging system checked (GOOD), but the light was still on. I pulled the plug for the CMU input and it was very badly carroded. Tried cleaning with alcohol and electrical contact cleaner and it would work for a day or so, then come back on. Even dipped both ends into a container of coke. Ended up replacing the connector and have not had a bit of problem since. Just be careful if you cut the connector on the wire harness side as it is very short.

[nascarnutt]

Thats something I haven't done. I know it's a stupid question but what is the CMU and where is it located?

[GeorgeS]

Computer Monitor Unit.

 

It is a couple of Circuit boards, inside the Center of the Instrument Panel.

 

To get to the CMU, remove headlight, and the windshield, then you can access the Speedo Cable, and a few bolts, to remove the entire Instrument cluster.

 

If you do this, be sure to Lubricate the Speedometer with light lube oil. Also greese the Speedo cable, as part of this job.

 

Also replace any burned out Instrument panel bulbs.

 

Also, the Circuit boards usually need some resoldering for cold solder joints, ( I have not done this, but sombody has the details and will supply them, if you need the info )

 

For cleaning electrical contacts. use CRC Brand, 2-26, electrical contact cleaner, Avialable at Lowes, and Home Depot.

 

You may have to remove some of the relays mounted in front of the Instrument cluster, if so , be sure to clean all those plugs also.