Any thoughts on mileage when noticing voltage problems?

Well, it's been a LONG COLD winter but we're finally seeing some warmer days and hoped to take a ride into work tomorrow. Bought the license tags, filled the tars with air and fired the old girl up. Everything looking and sounding good except my voltmeter was showing less voltage than it should have (1 YO AGM battery). Voltage was dropping down to 12 without any real load and then bouncing around to 13 and up and down. My volt meter is connected at the coils. Just wondering if there's a specific time people start seeing alt/regulator failures. I'm @ 90K with most of those miles relatively load free (except the last 10K with added stereo amp and light use of heated gear).

When I go out in the morning to warm her up I'll plug in my Digital VOM to see what it says. Drag the manuals out as well. Sure wish I still had my heated garage...

Was this at idle? If it is it might be all good.

Gerhard

Alternator failures are much more common on the pre '96 models with the 28 amp alternator. I see you have a '98, so an alternator failure is much less likely, as you have the 40 amp unit and you have not come anywhere near overloading it, from what you tell us.

Check your battery connections are clean and TIGHT first. 12V is lower than what you should be seeing at idle with a 40 amper. Try taking your voltage readings directly off the battery too, to see if there is a difference from your on board meter.

Bush said:

Try taking your voltage readings directly off the battery too, to see if there is a difference from your on board meter.

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Yup, could very well be the meter as the battery connection was steady 13.1 with a load while the meter was showing 11.9. Warmer today so will look a little closer and order a new meter if necessary. That's connected to the coils so I still have some concerns about that circuit. Been down that road before and cleaned it all up so will be surprised if it's in the circuit and not a faulty Chinese meter...

LarryC said:

Just wondering if there's a specific time people start seeing alt/regulator failures.

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Such depends on:
a) overload conditions (too many, high current farkels installed...)...
b) neglect of wiring by user...
( c) weather conditions; mild winters = riding year round = exposure to brine on the roads...)

Larry,

Check that 4 or more wire connector on the right side under the panel for burning, my ST 1100 2001 gave me this issue a couple of times in 152,000 miles.

Jim

jvick98 said:

Larry,

Check that 4 or more wire connector on the right side under the panel for burning, my ST 1100 2001 gave me this issue a couple of times in 152,000 miles.

Jim

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Ya lost me on this one Jim. Only thing I remember on the right side is the brake switch and turn relay.

Couple years ago I checked the entire routing of the ignition and cleaned up the ing switch and kill switch. I believe it's a bad volt meter.

Motorcycles are like airplanes as far as wiring is concerned. The designers are loathe to add any weight or bulk for bigger wires than needed for the design function. A function that often has a tolerance for a significant (to us anal types) voltage drop. If you check voltage on a branch circuit, you get a confounded reading. You really want to check voltage at the battery if you are concerned about overall system health and actual charging.

ST1100Y said:

Such depends on:
a) overload conditions (too many, high current farkels installed...)...
b) neglect of wiring by user...
( c) weather conditions; mild winters = riding year round = exposure to brine on the roads...)

Click to expand...

Could not agree more. IMO, 'b' IS top of the list. A common issue with ANY aging bike, not just our STeeds. The 28amp system is excellent by design,.....can't say so much for owners maintenance.......or lack of. 'Out of site out of mind' has its downfalls for those lacking the knowledge and skill-sets needed to recognize exposed to element electrical DO need occassional preventive maintenance. Waiting for the all important 'smoke' to escape locating a problem area is 99.9% of the time too late.......and can get very costly as opposed to a can of electrical cleaner and a small dob of dielectic grease as a preventatve measure.

Now that you know the voltage is good at the battery terminals, I would connect the VOM in parallel with the meter you have installed on the bike. If the readings are about the same & varying, then you have a bad connection somewhere. If they are reading way differently, then the installed meter is bad, of course.

If the readings are about the same & varying, it might be time to do the "Red Wire" bypass and maybe install a high amp relay ( I used a 45 amp relay ) to bypass most of the load current from the ignition switch. You may want to do that anyway.