Fan not kicking in

[turboxr]

I just finished my head gasket job and I bought a new fan from a 95 XJ. I installed the fan and checked the ground wire from the fan relay and I have power to the fan relay when the truck is running but the fan won't kick on. I'm wondering how long it usually takes at idle for the fan to kick in? I let it idle for 30min and it never kicked in. I'm leaning towards the fan relay, but is there anything else that could be not allowing it to kick on?

[87Warrior]

Is the truck getting warm enough to trigger the fan? IIRC, the fan won't kick on until 220-230 degrees. If your truck has AC, turn it on and check. The fan should always operate with the AC on.