check engine light

Hi,
1999 Jeep Grand Cherokee 4.0.
Check engine light came on.
Found out it was the cooling fan relay, replaced it.
Light will not go out. Tried the disconnect batt. cable trick. Still on.
Took it to Autozone and Oriley to have it scanned for codes, no codes.
Took it to the Jeep dealer they said that the engine cooling fan unit
was drawing to many amps.
So I replaced complete coolng fan and shroud unit.
Took it back to Jeep to have the check engine light deleated.
Would not delete, said it had a code cooling relay circuit bad.
Pulled plug on cooling fan relay, checked 4 wire plug with test light, all, OK.
Just for peace of mind, I took back relay that was new, got it replaced.
Installed it back in vehicle.
Took it back to Jeep Dealer to get light deleted, would not delete, and no codes
come up?
They told me they would have to have there tech man,
go over the wiring at $100.00 an hr. Don't think so!
Every thing works great the fan comes on when the temps up,
and comes on when the AC is on. But the check engine light will not go out?
Thanks for any help.