IMRC actuator issue

I've recently had the Service Engine Soon light come on on my '98 Windstar (3.8L). I've used a code reader and found that the P1537 & P1538 codes have been set. I've used this forum, along with other information on the web, and found out where the IMRC acutators are located and how they are supposed to function. I know that they are supposed to stay closed up to about 3,000 RPM and then open. On my vehicle, they stay open all of the time (hence the appearance of the two DTCs mentioned above). While testing, I found that if I remove the vacuum line from the "radiator side" actuator and hold my finger over the end of the line, I feel suction and the "firewall side" actuator will close. If I reverse this scenario by removing the vacuum line from the "firewall side" actuator and hold my finger over the end of the line, I do not feel any suction and the "radiator side" actuator does not close. Does this mean that, beyond the shadow of a doubt, the "radiator side" actuator is bad? These gadgets are anywhere from $200 on line to $250 at my local dealer, so I don't want to buy one only to find out that it wasn't the "culprit" after all. Thanks, in advance, for helping!

It does sound like you are correct in your diagnosis.
They have the actuators for $152.83 each at
http://www.trademotion.com/partlocator/index.cfm?siteid=214072
This is Millennium FORD in the Seattle area.
In case the link below does not work, it is under "Fuel System.... Fuel induction.... Air Inlet controls.... Control Solonoid. They list the Suggested price ($254.72) and their WEB price.
You might want to write down your VIN to include with your order.
http://www.trademotion.com/partlocator/index.cfm?action=getLocator&siteid=214072&chapter=DP2027&appSectionid=6&groupid=10024&subgroupid=20157&componentid=60329&make=10&model=Windstar&year=1998&catalogid=1

Also, you might want to email them to make sure that you are getting the correct side actuator. I think that the left hand actuator controls the right side, and vice versa......so you will want to double check to make certain that you get the correct part.
If you click on the " ? " next to the "add to cart", you will get to the correct place to ask them your questions(s).

The right side of the engine is the side that is toward the firewall.....as.....if the engine were installed as for a rear wheel drive vehicle, that would be the right side.

To verify which one is bad get a piece of vacuum line,connect one end to the IMRC actuator and suck on the other end to see if it moves.....this will tell, without a doubt which one is bad.....good luck