I'd also like to know if I got screwed by a mechanic...

I have a 91 Honda Accord and I've had a problem with my radiator fan not turning off after the car was shut off. The fan would sometimes run for 10 minutes or hours on end. I thought it was the thermostat cooling sensor so I replaced that, quick easy fix. That wasn't the problem. I eventually had to bring it into a shop to find out what was drawing the power to my radiator fan after the car was off, because it kept killing my battery. My mechanic at first couldn't find anything wrong with it; he couldn't get the engine temp. hot enough to engage the fan, therefore couldn't duplicate the fan running for hours to drain my battery. So I thought well maybe it was just the extreme heat we had on Monday and Tuesday and I asked if he could just charge the AC. I went to pick it up, $102.32 not too bad. One hour to diagnosis and $20 bucks for the AC charge. But when I tried to start the car, nothing, it was absolutely dead. I couldn't figure out why he wasn't able to duplicate the problem but when I go there it's dead. He suggested before I went to pick it up that it might be the radiator fan timer unit but he wasn't positive. I kept the car at his shop and he did figure out that was the problem, price of the part $145. He charged me for three more hours of work on the car and said that he had even more time into it. Wouldn't the electrical diagnostic find this problem, or would it really take that long to diagnosis. I feel like the $450 he charged me is too much, what do you think?

First of all, it is not that hard to "heat soak" the engine to duplicate your problem. Just letting the car sit there and idle for about 30 minutes will get the engine hot enough to engage the fans. Second, did you take your car to a Honda dealership? Because they should be able to find out what the problem is for an hour's diagnostic. Electrical problems are difficult to figure out due to the many components involved, however, your mechanic should've gave you credit for the first hour of diagnostic labor for the first visit.

IMHO, you paid too much.

That was probably my first mistake. Instead of going to a Honda dealership, I brought it to another service station that supposedly specializes in electrical problems. Instead of getting credit for the first hour’s worth of diagnostic it was added into the total price. I paid $145 for the timer unit, $20 for the Freon, and $273 to check why the battery is going dead and the cooling fan is staying on too long, diagnose bad timer unit, install the timer unit and recharge the A/C system. Something else I thought was shady was that he had my write the check out to him personally, rather than the business itself. Is that even legal?

. Something else I thought was shady was that he had my write the check out to him personally, rather than the business itself. Is that even legal?

Legal? Well who's to say. Shady, definitely. People have different ways of structuring their business. He's probably a sole-proprietorship and that would be the reason you would make the check out to him.

That was probably my first mistake. Instead of going to a Honda dealership, I brought it to another service station that supposedly specializes in electrical problems. Instead of getting credit for the first hour’s worth of diagnostic it was added into the total price. I paid $145 for the timer unit, $20 for the Freon, and $273 to check why the battery is going dead and the cooling fan is staying on too long, diagnose bad timer unit, install the timer unit and recharge the A/C system. Something else I thought was shady was that he had my write the check out to him personally, rather than the business itself. Is that even legal?

Was the person you wrote the check to the owner or an employee? If an employee, contact the shop and tell the owner that the employee did a repair and did not report the payment by taking the check directly. This would be considered fraud to the company (shop). He used the shop and equipment for personal gain. You can also contact the BBB and see if they are on the naughty list. Contact your local Honda dealershi and ask what a timer unit would cost and compare to what you paid. Did you ask for the old hardware? Did you get a receipt??