I've got a general question about troubleshooting.

A friend asked me to look at his inoperative forklift. I've got a huge amount of experience troubleshooting electrical / mechanical / hydraulic and computerized machinery, just not any time on forklifts. (I was a senior engineer at a Detroit automotive OEM, recently retired.) I'm not a rookie involving troubleshooting, including a hyper focus on keeping things safe.

I'm trying to find a electrical schematic for the forklift, so I can understand how the details work. I see manuals for sale on line approx $30 (download) but not sure if that is a waste of time or not.

There is even a guy on ebay selling a DVD with a multitude of manuals,

Anybody been here before? Are there any manual/schematic sales folks out there / online who are truly legit? There is no way to see what you are getting until you pay up first. Does anybody know if these are available retail from the manufacturer?

And I do see the warning on the bottom of this web page: WARNING: Forkliftaction does not condone the illegal distribution of copyrighted material. Please do NOT submit posts that may indicate an intent to share, exchange or trade copyrighted material such as service manuals, schematics, access codes, service tools or software.

So, with that said, what are the legitimate sources of troubleshooting manuals?

Any other hints, tips or tricks before I start this journey?

The machine is a Hyster R30F unit, and it no longer steers correctly. Cursory glance indicates it some sort of a electrical control issue, but I haven't really gotten into it yet. I wanted to look at the manual / schematic first.

Many thanks.
LBC