radiator fan

[fs563]

1994 overheated. It has a single fan but a high and low speed. The high speed fuse in the PDC needed to be replace. Done.
The service manual implies that the fan is always running at one speed or the other when the A/C is on but this fan seems only to cycle on and off. The temperature is ok. I bought a relay and put it in for the high speed ground relay, the high speed relay and the low speed relay.No effect.
I checked the fan supply.Four pins altogether. There are two pins as ground. There is a high speed one always on and a low speed one off and on against ground. Is it a fan motor problem?

[faulty585]

you dont tell us if fan cycles on when ac cycles but from what your saying i would hazard a guess ur not receiving a constant power signal when ac is on?