Altenator Diode Ripple

[Fulmar]

How serious is this?

My wife was driving her 2005 Focus last night and she said the battery light went on and off on her drive home (probably 10 miles).  No lights dimming or other electrical issues present.  So I went into work today and picked up our Argus Analyzer and tested her battery and altenator.  Battery passed (and its state of charge was 98%).  Now on the charging system check at idle tested at 14.5V but failed the Diople Ripple Test.  Battery light was not on when I was testing it on idle.  I have not driven it since this morning.

So I've been googling this morning looking for answers, but I'm looking for second opinions.  I understand the basics of what this is and what it can cause/do.  Would something cause a false reading on this?

[CAP1]

How serious is this?

My wife was driving her 2005 Focus last night and she said the battery light went on and off on her drive home (probably 10 miles).  No lights dimming or other electrical issues present.  So I went into work today and picked up our Argus Analyzer and tested her battery and altenator.  Battery passed (and its state of charge was 98%).  Now on the charging system check at idle tested at 14.5V but failed the Diople Ripple Test.  Battery light was not on when I was testing it on idle.  I have not driven it since this morning.

So I've been googling this morning looking for answers, but I'm looking for second opinions.  I understand the basics of what this is and what it can cause/do.  Would something cause a false reading on this?

check your grounds. make sure all of them are clean and tight. i think there's one on the cylinder head, just above the alternator.

 how many miles on the car? and what was the output amperage at 2,000 rpm?

[Fulmar]

65,000 on the car.  I'll take a look at the more closely at the alternator when I take it back into work.  The Argus I brought home won't read out the amperage of the system, I have an older one at work that will.  Will keep the thread updated.

[CAP1]

65,000 on the car.  I'll take a look at the more closely at the alternator when I take it back into work.  The Argus I brought home won't read out the amperage of the system, I have an older one at work that will.  Will keep the thread updated.

cool. you're always going to see some. i don't get too many problems with ripple. your best way to check that though, is to use an oscilliscope.

 i just did an alternator on a focus.....they're a pain in the ass........but it was intermittently not charging.......the voltage regulator was crapping out.

[Fulmar]

So yup, glad I paid a buddy a few bucks to do it.  That thing was a nightmare.  Everything's good now.  Saved myself about $200.

[CAP1]

So yup, glad I paid a buddy a few bucks to do it.  That thing was a nightmare.  Everything's good now.  Saved myself about $200.

yep. focus, ya have to take out the front motor mount...that's in the p/s fender.......then remove a fuel line(if i recall), and pull the engine forward about 4 inches.........

[Fulmar]

We actually moved the radiator tank a bit, and then went at it from the bottom.  Took the tire etc off.

[CAP1]

We actually moved the radiator tank a bit, and then went at it from the bottom.  Took the tire etc off.

i looked at that possibility, but didn't like what i saw......thought through the top would be easier. it's close to the same setup as a ford contour under the hood...and that's the easy way to to them.....

[Babalonian]

All that just to get to an alternator?  An alternator (something you go through about one for every 2-3 batteries IMO)!  Does anyone design and engineer a car well from top to bottom anymore?

[CAP1]

All that just to get to an alternator?  An alternator (something you go through about one for every 2-3 batteries IMO)!  Does anyone design and engineer a car well from top to bottom anymore?

no.

 if the designing engineers had to repair the crap they design......well......their designs would be a whole lot better.


look into the "cs" series  of alternators used in gm cars

[Dragon]

I usually unplug the bulb, light never comes on again.

[CAP1]

I usually unplug the bulb, light never comes on again.

alternator/battery light comes on, the alternator's gonna stop working if it already hasn't. at that point, you're running on battery. at 10 volts, things start getting "choppy". at 9 volts, the ECU shuts down, which means the car shuts down.

 on OBD2 cars, pulling the check engine light will prevent it from passing most state inspections.