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post #1 of (permalink) Old 08-20-2009, 03:20 PM Thread Starter
 
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Pesky Voltage Fluctuation Woes

Been lurking for a while and my first post is this and maybe someone can offer ideas. 1981 CJ and the charge voltage spikes up to like almost 16.5 then drops to 12, up/down back and forth. all lights go bright/dim and back and forth in concert with the charge voltage. the alt is externally regulated. 140 amp alt. replaced the regulator twice and no change. its intermittant-- can hit a bump and it either stops spiking or starts... replaced all known grounds w/ new leads and clean connections. had alt repair shop bench test the alt on a scope and its fine. am at wits end... have no confidence in driving it. volt meter on dash looks like a wiper blade in a rain storm. the spiking is not a constant up/down voltage or duration.. sometimes it slowly climbs in voltage until the meter is pegged, then drops to 12 and starts the slow climb over again. my regular mechanic had it for 2 weeks and could not find anything.

using a premier power welder and their alt. sent the kit back to PPW and they say its all OK on their end. the relay inside the control box keeps tripping-- click, click, click in concert with the voltage spikes. when the box is engaged for welding, which turns off the charging circuit, the alt screams a solid steady voltage. go back to charge mode and it goes all haywire. battery is a red top optima. tried a AC delco truck battery as a test and no change.

i can watch the voltage climb and drop on my DVM but it happens so fast. testing at alt, regulator and battery all same results. low or high RPMS, all the same, other than the spikes happen faster. If i add a load to the circuit, like the running lights, it smoothes out the spikes, but it still cycles up and down, just not as fast. maybe need to get an analog meter w/ a sweep dial to more closely see the spike limits?

a real mess-- any ideas?

tnx

mark
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post #2 of (permalink) Old 08-20-2009, 03:37 PM
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Welcome to the board! My suggestion? A stock internally-regulated alternator.

It might help to know how your system is wired? Where does the regulator get it's sample voltage? Can you put together a wiring diagram of what you have?

Your problem obviously sounds like a loose connection, but you seem to have hit all the likely suspects.

My only suggestion is be to run a separate ground wire from the alternator case to the regulator to the battery and see what happens. There can be ground problems due to poor connections between the battery, frame, body and engine, and even between body panels, like between the fender and the firewall. A dedicated ground wire will bypass all those possibilities. I don't hold a lot of faith in it, but it's an easy and cheap way to eliminate bad grounds as a possibilities.

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post #3 of (permalink) Old 08-21-2009, 11:59 AM
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Quote:
Originally Posted by Rarecj8 View Post
Been lurking for a while and my first post is this and maybe someone can offer ideas. 1981 CJ and the charge voltage spikes up to like almost 16.5 then drops to 12, up/down back and forth. all lights go bright/dim and back and forth in concert with the charge voltage. the alt is externally regulated. 140 amp alt. replaced the regulator twice and no change.
You need to do TWO things right away...

One is to clean/check all connections.
Your voltage regulator will have a smaller wire that hooks to the batter cable at some point, usually the starter relay (solenoid),
Make sure that connection is SECURE.

If that 'Sense' wire breaks connection, the voltage regulator will 'See' that voltage drop, and read it as the vehicle needing more current and open up the regulator.

The Second is to take pictures and/or diagram out the alternator/voltage regulator you have and post it up.

I'm trying to figure out what you might have that would have an EXTERNAL regulator on a Scrambler,
And I just can't picture anything right off hand...

And just for the record, it sounds like the welder control is taking charge of the rotor when it's not supposed to and causing the alternator to go 'Full Field'...
Despite the 'All Clear' you got from Premier...

So Many Cats, So Few Recipes...

Last edited by TeamRush; 08-22-2009 at 09:48 AM.
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post #4 of (permalink) Old 08-21-2009, 12:59 PM Thread Starter
 
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Thanks TR, will post up more details later-- am dealing w/ pesky clients here at work, LOL. But the Alt/welding system is a PPW.


Premier Power Welder high-frequency on board welders, high-amp alternators, charging systems, Ready Welder, trail, off-road
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post #5 of (permalink) Old 08-21-2009, 03:38 PM Thread Starter
 
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Quote:
Originally Posted by Jim_Lou View Post
Welcome to the board! My suggestion? A stock internally-regulated alternator.

It might help to know how your system is wired? Where does the regulator get it's sample voltage? Can you put together a wiring diagram of what you have?

Your problem obviously sounds like a loose connection, but you seem to have hit all the likely suspects.

My only suggestion is be to run a separate ground wire from the alternator case to the regulator to the battery and see what happens. There can be ground problems due to poor connections between the battery, frame, body and engine, and even between body panels, like between the fender and the firewall. A dedicated ground wire will bypass all those possibilities. I don't hold a lot of faith in it, but it's an easy and cheap way to eliminate bad grounds as a possibilities.
i have replaced all known grounds using 1GA welding wire w/ properly crimped terminal lugs. battery to body, to frame and to block. Alt case is also grounded to same set of cables. I have ran jumper wires from regulator/alt/battery w/ no change. The PPW alt uses a GM style plug.


go to this page at the bottom which shows the diagram lay-out and is exactly like i have it now. This was installed about 5 years ago and never ran right but i lived with it, now its getting really out of control. BTW, it welds like a mo-fo w/ great penetration.

On-Board Welder Installation Photos - Premier Power Welder high-frequency portable welder, installation diagram, pictures




BTW, i grew up in Centralia, not too far from you and long ago lived in Belleville, Alton and even Wood River. S,all world, but now adays, the west is the best... Most family is near Nashville.

mark

Last edited by Rarecj8; 08-21-2009 at 03:41 PM.
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post #6 of (permalink) Old 08-21-2009, 04:23 PM
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Cool! My son and his family live in Centralia. They have a balloon race and some bands playing there in the park this weekend, and we're going to try to make it for a little while.

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post #7 of (permalink) Old 08-22-2009, 10:14 AM
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Double posting, forum acting up again! Sorry!

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Last edited by TeamRush; 08-22-2009 at 10:18 AM.
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post #8 of (permalink) Old 08-22-2009, 10:18 AM
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So now I know you have a CS series Delco Remy alternator.
Probably a 130 or 140 series.

I also know they have patched in after the on board regulator and are taking control of the alternator function after the regulator...
Kind of a crude way to do things, but effective.



What's probably happening is you are getting the command from your welder control to power up for welding.
This is called going 'FULL FIELD'.

That means the rotor is charged with full voltage to make the largest, strongest possible MAGNETIC FIELD (Full Field) to make the STATOR in the alternator pump out largest possible current POTENTIAL.

As the current 'Backs Up', you see the voltage rise.

What I would tell you to do is unhook the two wires marked 'Regenerative Feedback' and see if the problem shows it's self...

Those two wires are probably the only thing used to take control away from your INTERNAL VOLTAGE REGULATOR, and if you break that circuit, the faulty PREMIER POWER WELDER module shouldn't be able to take control and drive the voltage way up like it's doing...

You have NOTHING to lose, since you simply have to unhook the wiring terminals and test drive for a while.
--------------------------

I would say what is happening is you have a broken component connection or wire connection somewhere on the welder circuit board, and that is causing the intermittent problems...

Bad solder joint, broken from vibration, bad crimp terminal connection, ect.
Happens all the time, and unless they smacked the box around to make the intermittent problem happen, they would have never seen the 'ISSUE'....

So Many Cats, So Few Recipes...
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post #9 of (permalink) Old 08-24-2009, 06:09 PM Thread Starter
 
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Thank you for all the replies. I *THINK* i have a solution. The spiking issue has dogged me for a number of years. It will all work fine and then one day hit a pothole (or drive over the RR crossing) and it all goes haywire. So it was all working fine until my recent Rubicon Trail run and i used the welder to help fix a broken TJ. The PPW welder is in either weld or charge mode. There is a master control switch for this. To weld, flip toggle to weld position, raise RPMS and burn rod. when done, RPMs back to idle and put master control switch to charge mode. At that time it would not go into charge mode. I had to rapidly move the master control switch on/off about 10 times to g et it to go into charge mode. so yesterday i gotto some deep thinking about the system and having read TR's post, thought it might be the switch. The symprom surely soulde like it is confused whether its in weld or charge mode. So I rapidly moved the switch on/off w/ engine running and suddenly all returns to normal. Either the switch or the internal relay is bad. But right now (knock on wood) its running properly and giving a smooth steady charge voltage. To be sure, i'll send it to the PPW folks with this specific observation and see what's up. I'm pretty good w/ a solder gun, etc but its their box, so let them have a look see.


Even drove it to work today...

Will post up when/if i have anything to report.

mb
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