Why the Resister??

[KarlS]

I installed an AGM battery and to turn off battery warning light I just sniped off the probe and connected the wire to a positive terminal of the fuse box and it seems to work fine. I just read the mod in the First Gen tech library and the post said to use a resister in the line before hooking the wire to a positive terminal. Is there some reason a resister should be used?

[bongobobny]

Limits current and gives the proper voltage level to the sensor. It is looking for around 6 to 8 volts, not 12 volts. Supposedly some people have had their CMI go up in smoke from 12V direct...

[GigaWhiskey]

http://venturerider.org/forum/showpost.php?p=235534&postcount=4

[Snaggletooth]

Yep...the probe itself is not much more than a mini battery. It generates juice when in contact with the electrolite in the battey. If the cell level drops...no more juice to the probe and no signal to the CMS so hence...the warning light. It puts out minimal power like Bongo said so a direct 12 volts has the ability to do harm.

 

Mike

[KarlS]

Thanks, going out now to install resister. STUPID question time. Is it possible that because of the lack of a resister it could cause my fuel gauge to act up? Today while riding I looked down and fuel light blinking and no bars on gauge. Then I had 2 bars, then 3, back to 2 then 1 then 0. Kept doing that. Filled up with gas (2.1 gal) and read full at 6 bars, then 5 then 4 then 5 then 6. you get the picture.

[Gene Kearns]

Yep...

 

Mike

 

Loved your sig line and as I went to steal it...... I found out Washington never said it! He said:

 

"A free people ought not only to be armed but disciplined; to which end a uniform and well digested plan is requisite: And their safety and interest require that they should promote such manufactories, as tend to render them independent on others, for essential, particularly for military supplies."

 

Found here.

[GeorgeS]

Hooking the wire Direct to 12Volts. WILL SMOKE YOUR INDICATOR PANEL !!!!

 

It might take a few miles, or an hour or so, but it will destroy the indicator panel !!!

 

Do the resistor mod

[bongobobny]

The gas gauge is most likely a separate problem. The float assembly is known to have problems. You can remove it, try to clean the wire wound potentiometer and the slider, and you can try to tighten up on it to improve the continuity, or just replace it but good luck finding another one...

[Marcarl]

Normally there is a resistor already in the line,,,, the green wire. Maybe you haven't cut it off and it is still there,,, if so, you're cool.

[elmicko]

Normally there is a resistor already in the line,,,, the green wire. Maybe you haven't cut it off and it is still there,,, if so, you're cool.

 

When I did the mod on my '86 the resistor was already there. Confused the crap out of me but I just hooked to the battery with what was already there and it's been fine for over a year.

[steve crossley]

Thanks, going out now to install resister. STUPID question time. Is it possible that because of the lack of a resister it could cause my fuel gauge to act up? Today while riding I looked down and fuel light blinking and no bars on gauge. Then I had 2 bars, then 3, back to 2 then 1 then 0. Kept doing that. Filled up with gas (2.1 gal) and read full at 6 bars, then 5 then 4 then 5 then 6. you get the picture.

it sounds like a bad ground . check fuel sender under seat to see if wire is grounded. sometimes wires can brake on the inside and look good on the outside.turn on ing. watch gauge while wiggling wires if it jumps around you have a bad connection my 86 did the same thing . ground wire was broken inside

[KarlS]

Normally there is a resistor already in the line,,,, the green wire. Maybe you haven't cut it off and it is still there,,, if so, you're cool.

 

Yes I too HAD a resister already there but if you look at the picture of the mod a resister was added and the resister that was already there was still left on. So in the mod a total of 2 resisters was used.

[mbrood]

Here's the probe off my bike... note the resistor right next to the lead probe. If you cut off the probe and attach the yellow wire to +12v switched, you are probably going to be fine (although, THAT resistor value was selected for a 6 volt source not 12). Cut off the probe AND resistor and hook the green wire to +12v and the detector IC in the dash makes magic smoke signals. All reports I've read is that the detector IC goes bye-bye but nothing else is affected.

 

http://www.bergall.org/temp/venture/probe.jpg

[Beau-Kat]

For the last month or so, I have been getting a battery warning icon on my 88's dash. The whole bike has been garage kept and is literally nearly perfect with only 16K on it now.

 

After it came on the first time, I checked the battery's health and my charging circuitry to find everything in good order.

 

So, anytime the key is on, engine running or not, the battery icon then is on most of the time, and the little red light will be flashing. Occasionally, but not always, they will both return to normal after riding a bit.

 

I started reading the resister mod posts. I went out and found a 1.5V AA Lithium battery connected between the negative terminal on the battery and the old probe's white spade connector.

 

Haven't heard of a 1.5 v battery mod before.

 

Just thought I'd ask if any of you have seen that.

[Beau-Kat]

(BUMP)

[bkuhr]

For the last month or so, I have been getting a battery warning icon on my 88's dash. The whole bike has been garage kept and is literally nearly perfect with only 16K on it now.

 

After it came on the first time, I checked the battery's health and my charging circuitry to find everything in good order.

 

So, anytime the key is on, engine running or not, the battery icon then is on most of the time, and the little red light will be flashing. Occasionally, but not always, they will both return to normal after riding a bit.

 

I started reading the resister mod posts. I went out and found a 1.5V AA Lithium battery connected between the negative terminal on the battery and the old probe's white spade connector.

 

Haven't heard of a 1.5 v battery mod before.

 

Just thought I'd ask if any of you have seen that.

 

The battery light is really a low battery fluid light. If running standard acid cell battery, 1. Need to keep sensor operational as fluid indicator(do not do resistor mod)

2. If warning light comes on check battery fluid level and refill ONLY with distilled water

3. If light comes on and fliud level is correct, likely end of sensor probe in middle cell of battery has deterioted and needs replaced

 

Only do resistor mod if replaced battery to a gell cell type of battery and can not install fluid probe. The resistor mod will then bypass the warning circuit, keeping the warning light off

 

FYI. Probe/warning circuit is designed to be installed in middle cell of 6 cell 12 volt lead acid liquid cell battery. Apx 2 volts/cell and probe installed in 4th cell from neg or 3rd cell from pos=8 volts to ground as detected for warning circuit, Due to resistor values some have used in mod, appears 4-8 volts will work to disable the warning circuit, not sure 1.5 volt battery will work, but it may. Warning circuit really only cares, with in limits, for some volts, or zero volts(dry probe above battery fluid therby low fluid)

Battery warning circuit does not give any indication to electrical/charging health of MC, low battery fluid level only.

 

Others state they have burned up their CMS computer displays by hooking probe wire directly to battery pos with out resistor=12v on sensor circuit . Would strongly recommend against this.

 

If you do use a 1.5v flashlight battery, ensure with out doubt that 1.5v battery neg is attached to frame/mc battrey neg. and pos attached to warning wire. To reverse this could put -neg 1.5 below or less than ground, and could have in effect MC charging 14-15 volts to ground(frame) +plus -1.5 volts below ground(frame)=16.5 volts potentional internal CMS. This voltage would be getting a little high, and unhealthy for the CMS:2cents:

[Beau-Kat]

If you do use a 1.5v flashlight battery, ensure with out doubt that 1.5v battery neg is attached to frame/mc battrey neg. and pos attached to warning wire. To reverse this could put -neg 1.5 below or less than ground, and could have in effect MC charging 14-15 volts to ground(frame) +plus -1.5 volts below ground(frame)=16.5 volts potentional internal CMS. This voltage would be getting a little high, and unhealthy for the CMS:2cents:

 

Yup. That's how it's hooked up.

 

Thanks for all of the great info.

 

And my battery is gel type, but I don't know how old it is. It was in the bike when I got it last fall. Battery load tests fine.

 

The local Radio Shack is only a mile or so from me, so I'm going there for the 2.2K resistor.

 

Rusty

[Monty]

I no longer have my '83, but I do have an instrument panel that is fine, except that one of the ICs has a big hole in it from hooking the sensor wire directly to the battery.

[KarlS]

Thanks, going out now to install resister. STUPID question time. Is it possible that because of the lack of a resister it could cause my fuel gauge to act up? Today while riding I looked down and fuel light blinking and no bars on gauge. Then I had 2 bars, then 3, back to 2 then 1 then 0. Kept doing that. Filled up with gas (2.1 gal) and read full at 6 bars, then 5 then 4 then 5 then 6. you get the picture.

 

 

By the way: As soon as I installed the 2.2K Ohm 1/2 watt resister the fuel gauge started working properly again. Looks like I dodged a bullet. Thanks for all the information.

[Beau-Kat]

Went out today and took another look at the '88 and why my battery icon may still be lit up.

 

You may recall that I have the AA battery mod instead of the 2.2k ohm resistor mod.

 

Removed the new AA battery I just installed in its holder the other day.

 

Found a loose connection under the coil spring in the AA battery holder.

 

Tightened that up, installed AA battery. Wahlah! Battery icon gone.

 

My wife and daughter are having some sort of FOO-FOO party in the house.

 

So, it ain't dark yet, I'm going for a ride.

 

Thanks for all of you folks' help.

 

Rusty

[VentureBob]

Having some issues with this MOD and could use some help. I know this all seems pretty simple but as far as I can tell I am doing everything that I am supposed to be in the MOD but I still have the battery icon and red flashing light. Could I have a bad cold solder on the board that would be causing the MOD to not work like it supposed to?

Edited July 23, 2010 by VentureBob

[mbrood]

VentureBob, if THAT wire is in series with the 2.2K resistor to switched +12 volts, the battery icon should go out... if the key is on when you connect it, it won't respond... it has to SEE the connection when the key is turned on.

[VentureBob]

I had built the wire with inline resister and had it plugged into the excisting plug and then attached to the accessory fuse but still no luck. I took apart the connection on the red and white wire in the picture as they were correded and I thought that was causing it to not have a good connection but even with bare wire to wire I still have the issue.

[bkuhr]

Having some issues with this MOD and could use some help. I know this all seems pretty simple but as far as I can tell I am doing everything that I am supposed to be in the MOD but I still have the battery icon and red flashing light. Could I have a bad cold solder on the board that would be causing the MOD to not work like it supposed to?

 

That is the correct red/white wire you have circled. attached resistor between this wire and battery +, preferably switched 12v, so you do not have current draw when mc not in use. With key on CMS should go thru bootup, then battery warning light should go out.

 

If not....the red/white wire is a direct connection to the plug on the back of the CMS. Could have a broken wire or, yes, cold/broke soldier joint internal the CMS. When you get the dash off and can get to the rear of this CMS, run a long jumper wire from Bat+, to resistor, to backstab the rear for the cms connector red/white wire pin, and try again. If jumper wire works, your red/white wire is broke-somewhere. If still problem, then problem internal CMS, and your almost there....

[VentureBob]

That is the correct red/white wire you have circled. attached resistor between this wire and battery +, preferably switched 12v, so you do not have current draw when mc not in use. With key on CMS should go thru bootup, then battery warning light should go out.

 

If not....the red/white wire is a direct connection to the plug on the back of the CMS. Could have a broken wire or, yes, cold/broke soldier joint internal the CMS. When you get the dash off and can get to the rear of this CMS, run a long jumper wire from Bat+, to resistor, to backstab the rear for the cms connector red/white wire pin, and try again. If jumper wire works, your red/white wire is broke-somewhere. If still problem, then problem internal CMS, and your almost there....

 

Thanks for the info, I will try to run the jumper wire to back of CMS and see what happens. Thanks for all the info