My son told me he saw the temp gauge was up to the redline one day. I was looking into reason why, such as possible defective water pump or thermostat. Some one mentioned it could be the fan. Apparently there are two fans in the Astro, one for the radiator and not sure where the other fan is located and it's purpose. Anyone may know?

There is only one fan on your Astro van. It's bolted to the engine and it is belt driven.
It does have a fan clutch that should be tested to make certain that it's working properly.
Check the coolant level before anybody else does. That way you'll know for certain if the system is low due to leaking. Any coolant puddles under your vehicle?
If all that checks out OK, look at the thermostat and the water pump.

There is only one fan on your Astro van. It's bolted to the engine and it is belt driven.
It does have a fan clutch that should be tested to make certain that it's working properly.
Check the coolant level before anybody else does. That way you'll know for certain if the system is low due to leaking. Any coolant puddles under your vehicle?
If all that checks out OK, look at the thermostat and the water pump.

Hi, how can I check this fan clutch and what does it look like? I'm trying to avoid unnecessary repair when I pull into some of these repair shops without knowing what most likely is needed. Thanks.

I searched for a picture but can't find the whole thing. The clutch is behind the fan blade.and the blade is bolted to the fan clutch, with the engine warm .and off grab the fan blade,and turn it back and forth you should feel some resistance as that's how it works when it gets to operating temp,or starts to get hot the clutch then engages to make the fan blade spin faster. It kind of slips until wahot and then it engages and spins to cool the engine off. If when warm you can grab the fan moving it back and forth and there's no resistance at all,chances are the clutch is bad. Hope it helps some.

Oh the fan and clutch are at the front of the engine right behind the radiator,and under a round piece of plastic known as the fan shroud. Good luck.

oh the fan and clutch are at the front of the engine right behind the radiator,and under a round piece of plastic known as the fan shroud. good luck.
Hi, thanks for the clarification. So this is the big fan and the only one in the van's engine correct? If so, it's operating and is it suppose to always turning when ever the engine started?

After further investigation on the parts, it looks like I was mistaking the AC compressor as the water pump. Looks like the water pump is located at the same location but below the compressor. Therefore, what I had describe the spinning and stopping is really the compressor. I can see when I turn-on the AC, the compressor enguaged and started to spin. However, it will stop for a few second and then go again, and then do the same again and again. So looks like that's a different issue/problem not related to high temp gauge going to red line.

Going back to the high temp issue, assuming AC compressor not related to this.
It seems like there's only few things that can cause this problem.
(1) water pump - From what I learned, it looks like if water pump, most likely there's leaking involved? I don't see any yet.
(2) thermstat - Don't know how to test the thermstat...
(3) belts - The belts seems to be OK (I don't see any slack but not sure... ), I can see everything attached to it is spinning.
Don't know if this help in describing my problem for your expert advise/opinion.

The thermostat, is found by following the top radiator hose to the engine. The water pump can be found by following the bottom radiator hose to the engine. Are you losing any coolant?