I'm not completely scared of the electronics on newer vehicles. Yes, they are excessively complex, but if you have a code reader, you can find and fix most things pretty easily. Even the cheapest readers are far better than nothing. If you have access to a pro-grade reader, things get easy.
My beater is an 01 Accord - 125K miles on it, paint is shot but the car runs very well. Check engine light said hello, OBD II reader said "Knock sensor". Took some time to find it, took some gymnastics to change it, part was $8 on eBay. SRS light came on (which means the air bags wouldn't work, so that's worth fixing), buddy has a Snap-On diagnostics computer, turns out the switch on the driver's side seatbelt buckle was bad. $5 junkyard part, fixed.
My weekend/holiday/flash special is a 2008 MB convertible (which never, ever goes to WalMart's destruction derby parking lot). A/C stopped playing nice. Wallet started quivering in fear . . .
I bought an MB specific diagnostics box from someone for $50, he'd paid $500 and it didn't fit his model, it was too late to send it back. MB uses a proprietary 37 pin connector, so the local FLAPS can't use their scanner to see anything.
The box is pretty smart, it covers several dozen models and runs a LONG list of tests. Plug it in, turn it on, select model and year, press go. "Module 41527 is out of range". OK magic box, tell me about "out of range". Answer from magic box: "Outside air temp -40C, humidity 0%." In Florida. In the middle of August. Right. Sure thing.
Module 41527 cross references to MB part number (something) and the dealer wanted about $400 for it. eBay had a used one for $11.72 delivered (really!), three screws, one plug, the A/C works again. Took longer to find it than to change it.
I regard these readers as simply another "special tool" to work on my vehicles. Nobody complains that they need to buy a Phillips driver when all that's in the tool box is a flat blade screwdriver because the Phillips is the right tool for the job. These code readers are the right tool for the job also (in this case, diagnostics), and keeps us owners from just throwing (expensive, non-returnable) parts at the problem until it is fixed or we run out of money.
Cheap OBD II code readers can be bought for $20, if you have any vehicle with OBD II, having the reader is your first line of defense. I do know that the green tractors have proprietary codes, but I have heard rumors that if you look around the internet, you just might be able to find something that will help you.
Best Regards,
Mike/Florida