Voltage Drop

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Oct 9, 2008 | 10:16 PM

Sleeps In Trees

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Road Master

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Voltage Drop

'02 Ultra, noticed fairing volt gauge dropping when I used the brakes. Investigated & found stator output to be 23-24 VAC at idle, around 50 VAC at 2000 RPM. No continuity to ground from either socket, & .1 ohm between the two. Ok, stator is good, right? Checked regulator next & found 1.5 VDC between either pin & ground - BINGO! Thought sure I'd found the problem, but installed new regulator & no help - still have the same problem. Further checks showed that the problem isn't isolated to the brake lights circuit, voltage drops when I push in the cig lighter too & more severe drop when using brakes, cig lighter w/passing lights on....to the point of headlights dimming a bit. I need ideas about where to look now.

TIA,

VicW.

Oct 10, 2008 | 11:02 AM

robzuc97

Road Master

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From: Peoria, AZ

Charging System checks

Sounds like the charging system is functioning. If you're at 13-14.7 VDC (even lower running but not less than 10.5 VDC if mem serves) on the battery even with the draws, you're okay. If you put in halogen or other high output lighting on, it will take some juice to power them AND the lighter. Probably not much help here but here's a test we did at school to see if the system is keeping up with the power demands of the bike + accessories. It does require special tools (Powerlink or load tester and multimeter w/ inductive lead. The DVOM inductive lead costs about $80) so it may not be possible to the DIY to do:

1. MAX CURRENT/VOLTAGE OUTPUT:__________AMP (MINIMUM OF 85% OF CHARGING SYSTEM RATING)
WITH POWERLINK or DVOM WITH INDUCTIVE LEAD CONNECT TO BATTERY TERMINAL +/-INDUCTOR LEAD ON MAIN C.B. {SMALL BLK WIRE TO REGULATOR} ZERO POWERLINK/DVOM SELF-CALIBRATES WITH BIKE RUNNING, REV TO 3K ADD POWERLINK LOAD OF 13V RECORD AMP VALUE {MUST BE LESS THAN 15 VOLTS}

2. CURRENT DRAW:__________ AMP
POWERLINK or DVOM WITH INDUCTIVE LEAD CONNECT TO BATTERY INDUCTOR TO BATTERY (-) DISCONNECT STATOR DEUTCH RUNNING REV TO 3K ENERGIZE ALL LOADS RECORD VALUE

3. CURRENT LEFT TO CHARGE BATTERY:__________AMP
SUBTRACT #2 FROM #1 RECORD VALUE

Oct 10, 2008 | 04:56 PM

Sleeps In Trees

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Road Master

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I don't have the equipment to do those tests, but thanks,

I did some checks at the battery posts approx 30 mins after I rode home from work today & found:

12.9 VDC on battery w/ign off

14.2 at idle, radio (w/Hogtunes amp & powered antenna) made no apparent difference

14.5 VDC at 2000 RPM

13.2 VDC at idle w/radio, cig lighter, & passing lamps on

12.6 VDC at idle w/radio, cig lighter, passing lamps, & brakes on (fairing gauge read 12V or slightly below)

Prolly get the battery tested for S&G's anyhow, but I'm thinking maybe I don't have a problem now. Don't these volt readings sound ok for my 45 amp charging system?

Appreciate the feedback fellas.

VicW.

Oct 10, 2008 | 05:38 PM

robzuc97

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From: Peoria, AZ

Idle and at rest voltages are a little low. Any loose or corroded connections? Doesn't take much esp. EFI bikes. Good idea for a load test; cheap test anyways. PS: No one can afford every piece of equipment needed to test! Would like to get the inductor pick-up for my DVOM though.

Oct 10, 2008 | 07:08 PM

Sleeps In Trees

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Road Master

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I'll check more connections at first chance, but in the meantime I'm not putting excess strain on the battery or charging components by running as it is am I?

VicW.

Oct 11, 2008 | 05:20 PM

Sleeps In Trees

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Road Master

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New wrinkle today: Thinking that the system is prolly ok, OL & I went for a ride. I was keeping a nervous eye on the volt gauge & somewhere along the way I noticed that the gauge didn't drop as I hit the brakes. Stayed right at 14.8 that time, but then acted the same as before for awhile after that. Hmmm. Then (of course) about 100 mi from the house the gauge dropped to below 10 volts when I applied brakes & recovered to only around 11 volts or less. Gauge never went any higher but seemed stable as long as I kept revs up at stops. We made it home.

With bike still hot I quickly checked volts across the battery posts & was right at 12 VDC. No voltage drop (0 VDC) across the two posts of the circuit breaker that the regulator hooks up to. Started it up & had 11.8 VDC at battery from idle to 2000 RPM.

The stator checked good - putting out 23-24 VAC at idle & showed .2 ohms between the pins, & no continuity to ground.

The new regulator showed 0 VDC to ground on one pin, & .19 VDC to ground on the other. Much different than it checked immediately after I installed it. Then it had .15 VDC to ground from both pins. I wish the manual was more specific, it says if it lights a bulb the regulator is bad. Will .15 - .19 light a bulb? Did I get a bad (Cycle Electric) regulator?

Anyhow, the battery is on the trickle charger now & I'm gonna have it load tested...if the regulator isn't bad & the battery tests ok I'm at a complete loss here.

Ideas...??

VicW.

Last edited by Sleeps In Trees; Oct 11, 2008 at 05:53 PM.

Oct 12, 2008 | 03:23 AM

robzuc97

Road Master

Joined: Nov 2007

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From: Peoria, AZ

Okay. Straight & cruel: If it is perorming well, fergetaboutit! I just tore my carb apart & guess what? it doesn't "perform as well as expected". Why not just riding it & quit worrying about it!