Help. Is Starter Bad? No Start

[warhorse]

I have to start my truck with starter fluid every time I drive. After sinking several hundred dollars and multiple attampts at repairing the glow plug system I gave up.

So Ive noticed my starter has been slowing down over the past week or two each time I cranked the truck. I went to crank it to go do a job, it started turning over, then wound down like the batteries were dying. I put them on charger over night and went back this morning to try to crank her again.
Again turning over was slow then RPMs just died down. Turn over was not fast enough to fire the starting fluid.

I then took the batteries out and to an alt rebuild place. He tested the batteries and said they were good /excellent. Brought batteries back, put them in after cleaning all contacts with battery booster and a battery brush. Greased terminals with grease. secured all terminals. Went to crank it and it sounds as if the starter is running but not engaging.

the problems seem to be just getting worse

any help appreciated

[asauer]

Most likely a bad starter- but before/while you take it out, inspect your cables very thoroughly. You've already cleaned up where the batteries are, which is good, but also clean up the engine block grounds. Visually inspect the entire length of each cable to ensure there are no abrasions which have compromised the protective jacket- they will rot away if so. Also look at where the insulation stops on each end of the cables- if the wire is corroded back into the insulation, they are junk.

On the positive side, I almost guarantee your truck will start quicker, and without ether onces you get the proper cranking RPMs.

[Snotzalot]

Starters don't last for ever.