The following PDF file gives cooling fan electrical etc. component
locations; directions on how to test them; and troubleshooting charts, all
for your 91 Accord:

http://media.honda.co.uk/car/owner/m...400/16-103.pdf

A manual for your Accord is accessible via
http://www.honda.co.uk/car/owner/workshop.html

Based on what you say, and going from memory from past posts here, I would
definitely first test the timer unit. They do go bad, causing the fan to go
on when it should not.

"Tirthankar" <tirthankar.sahoo@gmail.com> wrote
> The Fan in front of passengers seat is giving issues. It turns on even
> when the engine is cold on a morning before started. Recently I had
> changed Thermo switch at the upper hose and temp sensor at the
> thermostat housing lower hose. No helped at all.
> Only mystery is when I go for long drives the fan doesn't turn on. But
> on cold it does. However on turning on the AC swtich both the condesor
> fan as well as radiator fan come on. What could be the problem.
> Now a days I keep the battery terminal disconnected -ve to save the
> battery. Earlier also the fan used to run till it sucked the battery.
> Could it be a wiring problem.
> What is the difference between fan timer unit and fan relay.
>