fan troubles

[Delorean17@xxxx]

Hello, 
When my fans come on they stay on for a Long time and rarely turn off. 
They turn on exactly on the line below the 220 mark. Both of my cooling fans 
are rebuilt and work great and are spinning the correct way, etc., etc. 
Today I let the car idle for 10 mins until the fans came on and then got on 
the highway and traveled at 60 MPH for about 7 minutes and the fans never 
shut off until I got home and stopped in the drive way. What is up with 
that? They turn off once I stop....hmmmm. I continued to let it idle and 
they came back on and the fans ran for about 5 minutes and then shut off 
again. It is only about 65 degrees right now. How long should the fans run 
before they shut off again? I thought the fans should not come on if you are 
going over 50 especially when it is only 65 degrees. Keep in mind that my AC 
is NEVER on because it doesn't work. If I continue to drive fast they will 
shut off and then come on for a minute every now and then for no apparent 
reason.
I have the fan fail fix installed so the "fan fail" light illuminates 
when the fans come on I just installed a new DMC Houston otterstat so I know 
something else must be wrong. When I touch the coolant pipe coming out of 
the passenger side bottom of the radiator it is MUCH cooler than the other 
side so the radiator is doing its job well. When you get out of the car you 
can feel the warm air being blown from the cooling fans. What could be my 
problem? I have an overheat protector/bleeder installed along with the fan 
fix from Mr. Hervey. The car only has 17k miles and the water pump doesn't 
appear to have any signs of dieing.
I recently drained/flushed the system and added 50/50 premix back in so 
the coolant is mixed correctly. Someone said that maybe my timing is off and 
causing the engine to get a little hotter than usual but I don't think that 
could be it as the engine seems to run quite nicely. I also have the Bosch 
platinum 4 prong plugs installed but I don't think that would do it. I hope 
I gave a detailed enough description. It seems as my engine is just a 
running a touch hotter than it should or there is a failure somewhere in the 
circuit.

Any help would be greatly appreciated. Its not a big deal but it is going to 
drive me crazy until I figure it out.

Thank You
David