The only issue is if the solenoid contacts are poor the additional power could force a good contact and make the starter sound fine. The thing that I have seen on starters is the bushing wear causing the the armature to shift, some times more or times less, depending on its location withing the case. This causes excess drag that results in a slow starter spin, occasionally all lines up right and it will spin fine. It sounds like it will be worn bushings to me causing excess drag, i.e. slow starter spin.

 

Definitely check all connections and grounds as has been suggested. As far as a slow dragging crank mine turned out to be a starter that "tested" good. It was still cranking over OK to everybody else but to me it was slow. I went with a new Oreillys unit due to our shop discount and it cranks much better. And as far as starters go it's not if it's when it goes out. I chose to do it at my shop on my terms rather than wait until I was stranded.

 

I just came in from a 2002 with the following symptoms:

Slow crank. Intermittent WTS and other lights flashing on dash. Truck dies.

New batteries, alternator, and starter without improvement.

With the engine running, I checked both battery voltages on the posts (not the clamps). Passenger side over 14 volts, driver side 12.0 volts. They should be identical. Clamps on the driver side - 12.0 volts... juice not leaving the passenger side to the driver side. Checked the passenger side positive cable - 12.0 volts, while the posts said over 14 volts. The alternator was sending juice to the passenger battery, but the cable to the driver battery was corroded.

I disconnected the cables, cleaned everything with a wire wheel on my drill, and reinstalled. Truck cranked fast and strong. With engine running, check the voltages on the battery posts again. 12.65 volts and climbing on both batteries. The driver battery needed to charge up, and it was taking a little time for the voltage to rise at idle.

Here's what happened: This particular truck had 3 positive cables - one went to the starter and across the two batteries, one came from the alternator, and one went to the electronics on the truck. The one cable to the electronics was a separate cable on the driver side. Without juice leaving the passenger side, the battery on the driver side was powering the electronics without charging up. Once the voltage on the driver side dropped too low, blinking lights and stall.

My truck is configured with one single positive cable to everything, not three separate cables. When helping to troubleshoot - I'm thinking "Stinky", but now I know to think either modified or a different configuration for some other reason.

 

Thought I would post the an update:

New starter fixed the problem. Picked up one from Napa with life time warranty. I have the two hole version so removal and install was a snap. The two hole version makes it very easy to get to the upper bolt with extension.

Thanks for all the post. This site rocks! Feels good doing my own work with help from threads here.

Jed

 

Glad to hear it is all well!

 

Excellent, good to hear you worked it out..

 

Congrats! Thanks for posting the fix!

 

Great news!

It's probably like night and day difference, eh?

Keep an eye on your charging voltage, especially for a little while with the new starter.

Make sure it didn't hurt anything else

 

Congrats on the repair and reporting back. I also changed my starter not too long ago and reduced start time from 3 1/2+ seconds to 1 1/2 or less.