View Full Version : TA not charging, voltage drop while driving, alternator?

09-10-2011, 06:37 PM
Drove the TA to my parents tonight... on the way home, the check gauges light came on.

I felt terror and looked at the oil pressure and temp gauges... all good... but the voltage was in the yellow.

I pulled over, and shut her off, restarted, but was slow to crank.

Drove her home, and by the time I got home, it was at the 10 volt mark or so.

I'm going to check connections tomorrow , but I'm assuming it's the alternator?

Anything else to check?

09-10-2011, 07:26 PM
The alternator is probably low on fluid.

Could just do the old test of: start it, then disconnect the battery.

09-10-2011, 07:50 PM
Can I just top it off using blinker fluid?

09-10-2011, 08:11 PM
Were the dash and/or headlight flickering/pulsating as well? If so, and regardless, sure sounds like the alternator to me...

09-10-2011, 09:24 PM
The lights didn't seem to fluctuate, I didn't have the headlights on a the time.

I had the alternator replaced under warranty back in like 2002 (fugger did on me on the way to Speed Inc to have some work done.. after the work was done, I went to the dealership)

I'll check the wiring and likely pull the alternator tomorrow ... I need a new bulb for one of the reverse lights and my GTP needs a new driver side turn signal bulb .. so I have to stop by autozone anyways

(The Lucy Dog liked seeing the TA though :) (ignore the wiring hanging down , still fixing a few issues)


09-10-2011, 11:29 PM
Keep in mind, a bad or deteriorating battery can even make a new alternator fail -- speaking from experience. ;)

09-11-2011, 08:57 AM
connections A-OK ... I'm going to assume (yea i know) it's an alternator...

Recommendations on where to order a Direct replacement unit?

09-11-2011, 10:03 AM
There are tons of reman's out there.
You can even get a new one in 'Remy' from Rock auto or Advance auto.

09-11-2011, 11:36 AM
Pat, this guy look good to you then?

09-11-2011, 11:43 AM
Denso's are OK, it is so hard now a days keeping up with who does the remanfacturing for all these indivdual companies.
I know delco reman's have fell off reliablity wise some in the last few years.
If it has a lifetime warranty on it, you got that.

09-11-2011, 10:20 PM
Alternator ordered! (this really pisses me off.... I wanted to drive the TA to school Tuesday .... was finally becoming confident in her :( again)

09-11-2011, 11:50 PM
Could just do the old test of: start it, then disconnect the battery.

Just saw this, not a good thing to do on any car with solid state engine controllers.
For a newer ford really not good among others VW, Audi nissan.
Can cause major issues if the battery is disconnected while running.
It is the only dampening capacitor in the charging system.
The PCM/ECM wired directly to it for that reason.

09-11-2011, 11:57 PM
Ahhhh...good to know! So what's the easy way these days to diagnose an alternator failure? I haven't had to do it on any newer cars, but back in my younger days I learned if you disconnected the battery after starting the car and it died it was most likely the alternator.

09-12-2011, 12:13 AM
Well now a days it depends upon the system. Some are fine with the standard carbon pile load tester.
That loads the battery down & forces the alternator to near full field depending upon load placed.
Others want a bi-directional test with a scan tool to tell the PCM to field the alternator for a output test.
Either way special equiptment.
For sure a clamp style amp pick up is a must now. Non-intrusive easy testing.

Real easy to tell if your not charging, the output voltage. If it gets to around 12volts running you likely have an issue.
But that is subjective, you have to know the amperage. The more amperage produced, usually the less sytem voltage that is availible.
So voltage is only part of the picture. Not really easy for the DIY now to test these properly.

09-12-2011, 12:21 AM
Not really easy for the DIY now to test these properly.

Sounds like it...lol! I don't understand most of that now, wasn't any better 10-15 years ago.

New technology is nice, but it really sucks to have a lot of troubleshooting taken out of the non-mechanic DIY'ers hands.