Belt tensioner my belt slipped off?

Also I need to know step by step how to put belt back on and which pulley to start with

I have the 3.3L in a Dynasty and two Caravans. In the Dynasty, the nut can be reached from on top if you lay right in front of the antenna. I don't think there's enough room to do that on the minivans.

To release tension, use a long 15mm wrench on the bolt head in the middle of the pulley. If you're lucky and if you have just the right wench, it can be hooked on the metal bracket that holds the AC pipes to the right strut tower. Otherwise, you need two hands. One to pull on the wrench to pivot the tensioner pulley arm; the other to slide the belt off one of the pulleys.

As I recall, you have to go from underneath on the minivans and reach up to the plate the pulley is bolted to. You may need two different 15mm wrenches. One will get the nut loose, but you may not be able to turn it enough to get another bite on it with the same wrench. Use the other wrench to turn it a little more, then alternate back and forth a few times until you can turn the nut with your fingers.

When you install the new tensioner, observe there's a tab on its backing plate that has to seat in a small hole.

When you install the belt, the last pulley to slide it onto should be one without ribs. The idler pulley is a good one. The power steering pump pulley is good too, but you have to be working from the bottom as that's where that pulley is.

If your videos don't match up, be aware there was also a 3.0L V-6 engine. I have two of those too. They are totally different in design and a little harder to do this job on.

On Saturday I was able to route the belt around all pulleys except the alternator because I didn’t have enough slack to get the belt the Remainder of the way, I am not sure if I was turning tensioner bolt the wrong way, I pulled it towards front of car and the tensioner moved some but now it seems I cannot get it to move again or maybe o was not doing it the right way or do I push it towards back of engine, please explain more on how to put belt back on and how to route it best and how to get the extra slack to put it around last pulley

That's why I mentioned the last pulley should be one without ribs. Most people don't think of that, but in this case, the belt is not quite long enough to be pulled up over the lip on the alternator or power steering pump pulley.

If you are able to do this from underneath, have a helper pull on the wrench to move the tensioner pulley, then slide the belt onto the water pump pulley last. It's way down at the bottom, all the way to the front, and it is smooth with no lip to go over. If you have to do this by yourself, it feels a little awkward, but I use one hand to pull the wrench, then the other hand to push the belt down onto the stationary idler pulley. On the engine, that idler pulley is just above, and as I recall, just a few inches ahead of the tensioner pulley.

Tension on the belt is released by pulling the wrench forward, as though you were trying to tighten the bolt. I can't remember exactly which wrenches I used other than they were two Craftsman combination wrenches. The box end of the 15mm wrench goes on the bolt head in the middle of that pulley. The box end of the second wrench hooks to one tooth of the open end 15mm to give you a longer handle. That alone makes moving the tensioner arm much easier, but in addition, your knuckles will end up right next to a black, thin strap holding the aluminum AC lines to the strut tower, (body sheet metal). You can hook the second wrench on that strap. That keeps the tension released while you work with the belt.

It wasn't uncommon to run into a tensioner pulley with a pivot bolt that was rusted tight. You may still be able to move it with a wrench, but it won't spring back under spring pressure. When they're not rusted tight, you can usually make them move by tugging really hard on the belt. Also, when they're rusted tight, you may find when tugging on the wrench, the pulley's center bolt turns tighter without moving the pulley's arm.

One other thing to watch for, if the tensioner is fully released, yet the belt won't slide over a smooth pulley, more than likely the belt is not fully seated on a ribbed pulley. When this happened to me, I usually found the belt was riding up on the outer lip of the alternator pulley.

If you do have to replace the tensioner pulley, one suggestion is to visit a pick-your-own-parts salvage yard and find a 3.3L you can look at first. The 15mm nut is on the backside of the mounting plate, at the end of the bolt that arm pivots on. It kind of sits in a pocket, which is why one wrench might be enough. At the dealership, I had MAC and Craftsman wrenches. A coworker had Snapon wrenches. We borrowed them back and forth when we needed two different wrenches to start loosening that nut. I'm pretty sure there isn't enough depth to fit in a socket and ratchet.

My Dynasty has a lot of room between the engine and firewall, so replacing the tensioner can be done quite easily from on top. You don't have that extra room on the minivans, so it has to be done from underneath, from behind the front cross member. It's actually very easy with the van on a hoist. If you do this by raising the front tires off the ground, please be sure to use jack stands so you can come back to see us again.

I forgot to address your comments about the belt chirping and slipping off. Both of those are due to a pulley that is turned or tipped. The chirping comes from the belt sliding across a smooth pulley as it goes around it. There's a number of things you can do to identify this. One is to lightly dribble some water on the smooth backside of the belt while the engine is idling. That will make the noise change, usually it gets quieter. A second observation is to look at the black paint on the pulleys. It will be worn off in the center of the pulley, exactly the same width as the belt. If that shiny area is wider than the belt, that shows the belt has been running in a wider area. Either that pulley or the one right before it is turned or tipped.

The third observation is harder to do and harder to describe. That is, if you look down from on top, you should not see the edge of the belt peeking out on the lower pulleys. If you do, the belt is walking sideways over one of the lower pulleys.

Don't use any kind of belt dressing on serpentine belts. That stuff can make a squealing belt quiet for a little while, but it will become impacted with road dust and grains of sand that lead to worse squealing. At that point the belt must be replaced and the pulleys must be washed and scrubbed.