I would look at the cable to the starter, sounds like it isn't getting enough amps

 

i did all that on routine when I changed my old one and cables seemed fine at the time i do live at the Coast so maybe rust/corossion have wrecked havoc 🤣

 

Any codes?
My S90 starter recently went out. The car would start sometimes, other times it would crank but not turn over - apparently there was a short in my fuse box, it burn out my starter, the fuse box and the ECM (according to the dealership). This caused the voltage to drop to 0.1, which wasn't enough power to get everything turning.

 

havent checked codes yet will check this later on today but if I dont have any codes is it possible to lube up the plunger inside the solenoid ? or is it a big no no

 

Pull the codes... This will point you in the right direction.

 

Ok, so I vote that you wirebrush and clean all existing connections.
Both battery terminals and grounding cable.
Battery post shoe.
Cable connections to starter
Alternator connections and wire
Ground wire for solenoid.
Start with the basics and go from there,

Also recommend you look at the grounding straps on the battery and engine as well.
Get the battery tested as well.

 

ok so Ive done everything wirebrush on all connections even put a small grease film inside starter solenoid where plunger is and all earth stripes looks good Did this 2 days ago and starter works not a single click battery is good i changed it 3 years ago