car hauling ?

From : spot shot

Q: i replaced the batterys on my 97 turbo diesel last weekend. they were the original from-the-factory units so i expect after 170000 miles they were due for replacement. the truck wouldnt crank on a couple of cold mornings recently though although after i charged them up - everything seemed to work fine at least for another few weeks until the next time it wouldnt start. so the sears die-hard guy tells me i need an alternator replacement. he gives me this little printout of a test that indicates that the alternator has a bad waveform and needs replacement. his mechanic can do it later in the day with a napa alternator. i passed. from all indications i have the alternator is fine. the voltmeter fluctuates a but when cold - i presume due to the air heat grid - but after the engine warms it stays rock solid at slightly over 14 . just like it has always done. im inclined to think i dont have a problem. comments appreciated. tia. jim hall assuming you have a decent voltmeter. turn on the lights and heater blower. lights on bright fan on wide open. then check the voltage at about 1000 rpm. if its the same as with the stuff off you should have a good alternator. be sure to check the voltage right on one of the batteries. just because the voltage is there doesnt mean that the alternator is good. most meters will not show you a bad winding or diode at the high frequency that an alternator operates at and a high powered alternator can fool most meters. one of my multi-meters can measure frequency used to calibrate home generators and may detect a bad winding or diode but most voms dont have that ability since they are calibrated for 60 cycles ac which is way below what an alternator would be putting out even at an engine speed of 1000 rpm. -- if at first you dont succeed youre not cut out for skydiving .

Replies:

From : toxictavrn

well porky im not sure what youre testing for but it didnt work. maybe with a few more inches of snow......... g denny porky huh well this machine sorta did a dixie on me not so much the machine as a combination of comcast and microsoft. anyway chubs you answered so it passed the test. supposed to get snow and ice tonight then up to 50 thur. then just for the colts it is supposed to be real cold for the weekend. we will see how they do off the carpet and out in the weather. roy .