Engine/Transmission (1994 - 1998) Alternator problem ???

[J Shocik]

Greetings, I am having a problem with my '97 CTD. After starting the truck, the alt. needle doesn't fully recover to the middle of the volt gauge, it stays to the left (discharge). When the truck warms up and is on the street, the gauge is more to the normal position, at stop lights at idle, back to discharge. I don't have any warning lights on (yet). Is this an alternator problem in it's budding stages? The truck has 91,000 on it. Thanks, John

 

[Tardog]

Maybe your grid heaters are sticking on? I'd say that the life of your altenator may have come to it's end. You can get your system tested at most parts stores or even Walmart?

 

[J Shocik]

Tardog, I was wondering about that! So when I start it up, I let it idle for about 30 sec. then I run it to about 1200 RPM for about 1 min. I can see the grids cycling normal (watching the alt. needle bounce back & forth, then the needle stays at 14 until it returns to idle then back to 10). That & researching other threads about alt. problems show my truck is at the stage for an alt replacement (rebuild if not too hard). I have a snow plow & all the hydraulics are sitting just above the alt. so when I change the alt. all the hydraulics have to be removed first. So when I take the alt out, a new one is going in hopefully. I don't want to keep taking it out, putting it back, taking it out... I just want to do the job once, and right, and for the right reason. Thanks, John

 

[mechanic]

I would recommend checking the voltage at one of the batteries with a DVOM and see what it is there. A system drain can cause a dash gauge to read lower then the actual battery voltage. While you have the meter there check the termeials on the grid heaters to see if they are cutting out as they should. If these tests don't show anything, then you may just need brushes. If it is a turkey to remove, a new one may be the best bet. David Lapham

 

[J Shocik]

When I start the truck, after it gets oil pressure, I bring it from idle to 1200 rpm, and everything works fine, with the alt. reading what is normal for my truck. I can watch the gauge and see the grids cycling. I believe they are working fine. At road speed ( anything above 1200rpm ) the alt. seems to be working, at idle (below 1000 rpm ) the gauge shows discharge. Reading other threads with alt. problems, an alt. change fixed it. I will hook up a voltmeter to check further.