Wednesday, August 31, 2016
2001 dodge ram 1500 5.2 alternator not working
I'm working on a friends truck that the battery keeps dying. He got another alt from the salvage yard and its doing the same thing as the original. The gauge in the dash will read about 13 volts while idling but if you take it for a drive the check gauges light will come on and the charging gauge will drop as far as it can. it has power to the main feed from the battery to the alt but not to the two smaller wires plugged into the back of the alt. any ideas?
If this is one of the type of alternators that has the integral
regulator built-in, there should be a place where you can insert a
Phillips screwdriver or small metal rod to ground a tab on the
regulator to force the alternator to put out full current. If it has
that and it doesn't put out full current at a higher than normal
voltage (should be over 14 volts, could be close to 15 volts), then
the alternator is at fault. If it does put out that voltage and higher
current then perhaps the regulator is faulty if the voltage doesn't
stay around 13.5 volts when the alternator is running without using
this trick to test the alternator.
You can get a decent current tester like this one:
to check current. It clips over the battery cable. If you reverse the
connection it will reverse the direction on the meter, so make sure
you're reading current output from the alternator. The smaller channel
on the rear of the tester is for lower amperage readings. The larger
one is for starting current.
Is the battery in good condition? Does it hold a charge?