Recent Topics
Naked Engine ?
by HTSS_TR
08/04/15 12:42 AM
New Clutch in 98 Ranger
by Scout1
08/03/15 11:33 PM
Cat. converter, muffler, something else?
by GpB311
08/03/15 10:50 PM
cummins no crank 911 HELP!
by turbodieselfreak
08/03/15 10:42 PM
My fourth intake manifold leak. Cheap failing cars
by MikeHigg
08/03/15 10:37 PM
oil filter cutters
by mjoekingz28
08/03/15 10:07 PM
Need help -- wood stain spilled on truck
by gfh77665
08/03/15 10:03 PM
2011 Honda Accord....thoughts/w
ho owns one?

by gregk24
08/03/15 09:52 PM
Mystik 15/50 SM/CJ4 - 2014 Road King - 2,809 Miles
by alarmguy
08/03/15 09:42 PM
"Core Temp" - CPU Temperature Monitoring
by ZeeOSix
08/03/15 09:34 PM
What could this be a symptom of?
by Rolomoto
08/03/15 09:28 PM
Cubcadet 54" cut kohler 24hp 7000 motor
by dslofti
08/03/15 09:03 PM
Newest Members
ptkdude, Warwagon, SWFL, frodo84, eric4ok
54919 Registered Users
Who's Online
31 registered (bbhero, Bandito440, Bugzii, b1amgm47, Dak27, Char Baby, 4 invisible), 571 Guests and 75 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
54919 Members
66 Forums
235372 Topics
3787009 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Topic Options
#3228253 - 12/26/13 12:27 PM Alternator? Bad ground? Something else?
DemoFly Offline


Registered: 06/03/12
Posts: 723
Loc: Bremerton, WA
Car: 2003 Mazda 6 2.3L

Symptoms: Power surges low every 20 seconds or so. Headlights dim, blower motor slows down. The rest of the dash lights and such seem fine.

Battery is at tip-top charge after running. Battery is also only a couple months old.

It literally seems as if something is drawing 200+ amps every 20 seconds.
_________________________
Pushrods, please.

Top
#3228262 - 12/26/13 12:30 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Rand Offline


Registered: 08/20/03
Posts: 8967
Loc: Barberton,Ohio
Is that at idle or any speed?

how many miles?

possibly worn out alternator.

if it does it that regularly.
put a meter on the battery and see what the volts are
when its doing this problem.

If its dropping down to battery voltage you probably have an alternator issue.

alternatively you can pull it and have it tested.


Edited by Rand (12/26/13 12:30 PM)
_________________________
2015 Forester I-Premium 6MT

Top
#3228263 - 12/26/13 12:30 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Quest Offline


Registered: 12/19/04
Posts: 7064
Loc: beaver land EH?
get some voltage readings for us first before we can start our discussion on the subject.

Q.
_________________________
"Internet discussion boards act as echo chambers for conspiracy dittoheads" A.Allen

Top
#3228283 - 12/26/13 12:45 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Donald Offline


Registered: 03/21/04
Posts: 15431
Loc: Upstate NY
Most alternators are grounded via the alternator housing. So it may not hurt to loosen things and wire brush that area.

So a 10 year old alternator with over 100K probably. Is this the one that came with the vehicle?

Have it tested at a rebuild shop, it may be something cheap like new brushes.

Having your alternator rebuilt at a rebuilt shop is better than getting a rebuilt from AZ/AAP that was done overseas.
_________________________
2015 Subaru Forester 2.5 engine/CVT PP & M1
2001 Jeep Grand Cherokee Laredo 4.0 - PP & M1
1999 Dodge Ram 2500 w/Cummins - Rotella T6 & M1


Top
#3228297 - 12/26/13 01:00 PM Re: Alternator? Bad ground? Something else? [Re: Donald]
DemoFly Offline


Registered: 06/03/12
Posts: 723
Loc: Bremerton, WA
Originally Posted By: Donald
Most alternators are grounded via the alternator housing. So it may not hurt to loosen things and wire brush that area.

So a 10 year old alternator with over 100K probably. Is this the one that came with the vehicle?

Have it tested at a rebuild shop, it may be something cheap like new brushes.

Having your alternator rebuilt at a rebuilt shop is better than getting a rebuilt from AZ/AAP that was done overseas.

Original alternator.

Voltage @ batt terminal starts at 14.1v and slowly climbs to 15.5v then drops to 12.4v then jumps to 14.1v and slowly climbs back up to 15.5v and then repeats the cycle.
_________________________
Pushrods, please.

Top
#3228301 - 12/26/13 01:03 PM Re: Alternator? Bad ground? Something else? [Re: Donald]
AndyinAL Offline


Registered: 03/14/10
Posts: 26
Loc: Alabama
AC compressor cycling (loss of power) coupled with the engine and condenser fans kicking on at the exact same time (momentary voltage drop due to electrical load of fans)???

Just a thought. Seems as cars and systems age, engagement is not nearly as seamless as when new.

Maybe the system is overcharged / restricted by chance. Could explain the increased load when compressor engages, then shortly shuts off because of hi pressure safety switch. Seems like with modern vehicles and automatic climate controls there are very few settings that keep the compressor turned off. Notice when sitting at a stoplight, regardless of temperature, AC compressors of surrounding cars are cycling on and off for no apparent reason.


Edited by AndyinAL (12/26/13 01:10 PM)

Top
#3228307 - 12/26/13 01:12 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
SrDriver Offline


Registered: 12/09/06
Posts: 2599
Loc: Southeast Alabama
Remove and take to local rebuild shop. They can test and rebuild it and if done right is better than a replacement.

Top
#3228314 - 12/26/13 01:21 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Donald Offline


Registered: 03/21/04
Posts: 15431
Loc: Upstate NY
Originally Posted By: DemoFly
Originally Posted By: Donald
Most alternators are grounded via the alternator housing. So it may not hurt to loosen things and wire brush that area.

So a 10 year old alternator with over 100K probably. Is this the one that came with the vehicle?

Have it tested at a rebuild shop, it may be something cheap like new brushes.

Having your alternator rebuilt at a rebuilt shop is better than getting a rebuilt from AZ/AAP that was done overseas.

Original alternator.

Voltage @ batt terminal starts at 14.1v and slowly climbs to 15.5v then drops to 12.4v then jumps to 14.1v and slowly climbs back up to 15.5v and then repeats the cycle.



Over 15v is too high if you are measuring it at the battery with a quality meter.

Remove and bring to a rebuild shop.
_________________________
2015 Subaru Forester 2.5 engine/CVT PP & M1
2001 Jeep Grand Cherokee Laredo 4.0 - PP & M1
1999 Dodge Ram 2500 w/Cummins - Rotella T6 & M1


Top
#3228315 - 12/26/13 01:22 PM Re: Alternator? Bad ground? Something else? [Re: SrDriver]
Donald Offline


Registered: 03/21/04
Posts: 15431
Loc: Upstate NY
Originally Posted By: SrDriver
Remove and take to local rebuild shop. They can test and rebuild it and if done right is better than a replacement.


Unless your original is a Mando (Korean) alternator and if so get a Delco to replace it.
_________________________
2015 Subaru Forester 2.5 engine/CVT PP & M1
2001 Jeep Grand Cherokee Laredo 4.0 - PP & M1
1999 Dodge Ram 2500 w/Cummins - Rotella T6 & M1


Top
#3228339 - 12/26/13 02:02 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
TFB1 Offline


Registered: 09/03/10
Posts: 2896
Loc: VA
Originally Posted By: DemoFly

Voltage @ batt terminal starts at 14.1v and slowly climbs to 15.5v then drops to 12.4v then jumps to 14.1v and slowly climbs back up to 15.5v and then repeats the cycle.



Sounds like it's over charging then "catches it'self" and cuts out completely so you just have battery voltage... Assuming the connections are OK you could replace the regulator but most are internal these days(a few are mounted externally on the alt) requiring dissambly of the alt...

Top
#3228411 - 12/26/13 03:22 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Quest Offline


Registered: 12/19/04
Posts: 7064
Loc: beaver land EH?
Make sure that your A/C compressor is not cycling, and your engine has reached normal operating temp.

Measure your voltage reading again: should be within 13.5V ~14.5V DC without fluctuations.

If it fluctuates, and assuming that there are no other parasitic loads elsewhere (such as rear window defroster, A/C compressor cycling, etc.), then suspect that your alternator is at fault.If it's a Nippon Denso varieties, get a remain from Denso(ditto for Mitsu).

Q.
_________________________
"Internet discussion boards act as echo chambers for conspiracy dittoheads" A.Allen

Top
#3228485 - 12/26/13 04:55 PM Re: Alternator? Bad ground? Something else? [Re: DemoFly]
Dufus2 Offline


Registered: 12/12/13
Posts: 231
Loc: Virginia
I had a similar experience with the supply wire to the battery and possibly a fusible link. Check your wiring before condemning the alternator. Also, there may be issues with the F terminal going back to the ignition, cycling the alternator just like the A/C works.
_________________________
ASE Certified in Med/Heavy Truck Service including A9
Heavy Equipment Repair, Fleet Maintenance
Real Cars Rattle and Smoke a Little

Top
#3228948 - 12/27/13 07:25 AM Re: Alternator? Bad ground? Something else? [Re: Dufus2]
JetStar Offline


Registered: 10/02/08
Posts: 1106
Loc: Flatlands of Indiana
Is your alternator output controlled by the computer?
_________________________
My weakness is I love all motorcycles regardless of brand
2015 Road Glide
2007 Yamaha FZ1
1978 Suzuki GS1000 (now 1085)

Top