1989 240 wagon has a starting problem that I can't solve myself.
Problem: The car just "clicks once" when attempting to start it. Occasionally it will start and crank over just like the days of ode.

The battery is good and fully charged. I replaced the starter with solenoid with a good used one from my Volvo treasures of the past 42 years of driving these cars. I replaced the red positive cable (brand new) to the starter and cleaned all of the connections. I checked the 25 amp in line fuse and also the fuse box for corrosion.I thought it might be the neutral safety switch but I tried moving it around a bit while holding the key in the start position. Tried it neutral too.
Nothing but one click. But sometimes, I'll go out to the garage and will crank over rapidly and start just fine.
Could this be that ignition switch off the back where you put the key in ?
Volvo 9447805 ?
I'm losin' my hair with this schtunk.