Battery bypass not working!!

Hey everyone, I just recently bought a 750 maxim and am having some serious troubles trying to bypass the battery sensor. I have tried tried the 2kohm (actually used 2.2kohm) in series method with no luck. Will it not work with a 2.2kohm resistor? The voltage coming through the bypass was still at battery voltage (12-14) when I measured it at the point where the bypass connects to the other wire. The sensor seemed to go off when the bike was idling, but soon after I started riding it would go on again.

I also tried a voltage divider to lower the voltage to a little over 6 volts (which is what the sensor sitting in the battery would supply) where the bypass and other wire connect. The light won't even go off when the bike is idling with that one.

What could be going wrong with this thing?

Is it possible the panel/"computer" could be damaged? How could I tell if it was?

Also, does anyone know what the range of voltages the sensor will allow to shut off the light? I was thinking it must be between 5-7 or so.

 

Check your stator output voltage, and the voltage at the regulator output. The 2.2k ohm resistor will work fine. The warning light is trying to tell you something.

 

Okay, at around 2000 rpm I'm getting a reading of about 13.4 volts

 

That is low. Check your alternator brushes (there are wear limit marks on the brushes), clean the rotor contacts with an eraser, and see if that voltage improves. You should be seeing 14.5 to 14.7 volts at 2,000 RPM.

 

forget the resistor and put b+ to that wire
or
use a 5K pot in place of the resistor, turn it till the light goes out, measure it and make a resistor that value.
then check your alternator brushes

 

I made my own with a 2.2k Ohm resistor. The light works perfectly.

 

Ill test out the 5K pot idea and see what it gives me. Now I'm concerned about the charging system! The PO put an after market headlight on it, is it possible that could be affecting the charging voltage? Should I test the system without the headlight fuse in? Just thinking about what else could be causing this and hoping its not the alternator... Ill check the brushes tomorrow

 

What wattage is the headlight?
Your regulated voltage shoudl still be above 14v, but additional load could be preventing the battery from charging. There is some headroom for accessories, but not much.

 

Isn't the battery sensor for fluid level only not volts, mines direct to battery + and been that way for about 5 years no problems. I've got a sealed battery anyway so can't use a sensor.

 

Just took a look at the brushes, they seem fine, still a decent amount left according to the wear indicators. The contacts seem pretty dirty though, especially the inside one...the eraser did a little bit, but it still looks like it could be cleaner. Is it safe to use a some isopropyl alcohol on a rag to clean the contacts?

I'm not too sure what the wattage is on the headlight...I'll take a look though

 

the instructions says it is for sealed cells

I just read this thread
http://www.xj4ever.com/HCP14180 battery sensor bypass.pdf

 

The original battery sensor was a electrolyte level sensor. It uses a float and a variable resistor (just like the fuel level sending unit). That variable resistor would trigger the warning light when the voltage dropped below a preset point (as the float drops the resistance increases; as the resistenace increases less voltage passes through to the systems monitor). The bypass takes advantage of the fact that the systems monitor is looking for a voltage drop, and turns what was a electrolyte level sensor into a low battery voltage sensor.

FWIW the original style sensor is still available from a few battery manufacturers, but you have to ask for it when you order you battery.

 

the story on the battery monitor goes like this. The sensor goes down and touches the "water" and makes it's own little battery. when the water gets low it doesn't touch the sensor, and the battery is no more, and the light comes on.
the wire that runs the battery sensor takes a contact of it's own in the key switch. So if you go with a resistor and change the level sensor to a voltage sensor, you've freed up a contact in the key switch to use for something else and not added any extra switches

 

I purchased my battery sensor from a Honda dealer before I found this site. I believe it was pretty inexpensive and I have seen them in the XJ4ever catalog.

I think its pretty handy to be reminded to take a look at the battery level once in a while and it works perfectly. Could be the reason why my cheap $30 Walmart battery is on its 5th riding season.

 

I built the battery resistor bypass using a 2.2 k resistor. I tested the voltage going to the sensor wire and it shows battery voltage. Is that normal?

 

Yes.

 

Without sounding like a idiot, what does the resister do? Also i hooked it up to the battery side of the solenoid, so it has constant 12 volts. Is that the right way to wire it up? Some people use the tail light power because it is switched. Which is the best way?
Thanks,
Steve

 

The resistor actually should be giving a small voltage drop, but not enough to notice unless you have a good meter. You should be seeing in the neighbor hood of 11.88 volts after the resistor.

The sensor should be connected directly to the positive battery post so the systems monitor is being fed directly from the battery. The point being that you really want to be monitoring battery voltage, and not battery voltage after other wiring losses. Other methods are valid, so long as the voltage feed is live when the ignition switch is turned on; you'll just be seeing something slightly less than the actual battery voltage, so you may get a low battery warning at a higher actual battery voltage.

 

If your LED display is not clearing the Batt warning, you need to think that the signal is not making it back to the connectors in the headlight assuming your charging system is working correctly.
Your new battery by pass is just become a voltage monitor not an electrolyte level monitor. If you have a wire schematic for the bike, follow the wire back up to the ignition switch and from there into the headlight. I might suggest to by pass the wire at the ignition switch for testing purposes. I have found the contacts inside the switch get kind of funky after all these years and need a good cleaning. Check all the bullet style connectors and clean and treat with dielectric grease.
If you can find the wire in the headlight you can always start by ohming the wire out and see how much resistance before you start checking the ignition switch and all the other connectors in between.

 

It seems to be working like it was designed to do. Thank you for the information and confirmation.

 

Now if i could get her to run properly. Rebuilt the carbs still running lean. I will be checking the manifolds for a vacuum leak.
Thank you.

 

Thank you, seems to be working properly. It does clear the battery indicator light.