On my 96 Accord 2.2 4cyl. I installed a new radiator after the top tank cracked. Up until this point the car never overheated. After installing the radiator, I notice the temp. rising in stop and go traffic. I found out that the radiator fans were not coming on. Then after I turned the car off one of the fans came on. I tested it again and then both fans came on while the car was idling and stayed cool. I tried it again and the fans would not come on while running and overheated, but would while come whil off.

Any ideas?

Tom