Why does the fuse immediately blow on my power door locks? how to fix this?

If both the coolant hoses are hot then the coolant is passing through the heater core. You probably have an actuator or blend door that is not working. It may be restricted by commanding it to work. A scanner could help you find out the problem.

The first thing to do is check all the fuses, but it sounds like you need a mobile auto electrician.

Fuse Box Diagram Dodge Nitro (2007-2012)

https://fuse-box.info > dodge > dodge-nitro-2007-2012...

In this article, you will find fuse box diagrams of Dodge Nitro 2007, 2008, 2009, 2010, 2011 and 2012, get information about the location of the fuse panels ...

..

This is a common problem for the nitro. A few people have reported that waiting for the outside temperature to cool makes the locks work again. Some people have had to take it into a dealer to get the PMC Module replaced. Check and make sure your voltage is correct on the pmc module and make sure nothing else is draining it. This link should help you out.

https://www.carcarekiosk.com/video/2010_Dodge_Nitro_SXT_4.0L_V6/fuse_in

Open the front doors and look on the sides of the dash for a pop off panel

What # fuse's J5 25amp , J4 25amp , M 30 15amp , M13 20amp M33 10amp . All these fuse's are power supply's for door modules and to the wiper / washer switch . The washer pump is controlled by the totally integrated power module . I suggest you google TIPM - dodge totally integrated power module . Chrysler , Dodge , Jeep all use this componet . Also watch youtube videos on finding a automotive electrical short . That's what you have a direct short to ground on those power supply circuits

DODGE NITRO SERVICE REPAIR MANUAL 2007 2008 DOWNLOAD

for the easy solution download the pdf file

Door lock actuator needs to be replaced

You have to start with removing the door panel as follows:

CAUTION: Pay close attention to the plastic hook attachment points on the inside of the door trim panel. Make sure that every hook is correctly positioned to the door when installing the trim panel. Damage to the trim panel will occur if the hooks in the door panel are not properly positioned to the door during installation. 1. Connect the electrical connectors and install the power window switch. 2. Carefully install the door trim panel (4) to the door (1) by lifting upward and over the door lock into the trim panel then attach the trim panel to the carrier plate attachment points. 3. Install the screws (2) and the cap screw covers (3) to the front door trim (4). 4. Install the fastener (5) at the handle area of the front door trim (4) and tighten screw to 5.5 Nm (50 in. lbs.). 5. Install the door handle trim bezel (6).

1. Install the mirror assembly (1). 2. Install the three nuts (2) and tighten to 7 Nm (65 in. lbs.). 3. Connect the electrical connector (3). 4. Install the trim panel

change horn relay

There is casting sand in it (the heater core) and its stopped up. I just fixed an 08 nitro for nothing. Remove the heater core hose closest to the motor at the firewall. Cut off a piece of garden hose about 4 foot long and slip it over the core pipe, so you can flush it out. Now remove the other hose but leave the hose attached to the core. You will be unhooking it downstream on another pipe by the exhaust. Now get an empty milk just to catch the antifreeze and sand. Use compressed air to blow the antifreeze out. I used a 10 gallon air tank with a blow nozzle(rubber tip). Get some hot water from the sink and fill it up through the garden hose and repeat the blowing out. Reverse hoses every other time you blow it out. You will see sand in your milk jug at the bottom. It only takes a teaspoon of sand to stop it up. When you stop getting sand your done but dont forget to top the heater core back up with antifreeze. Your done for free. Chrysler wanted $1200 to fix my daughters nitro and I did it for nothing. Works like new again. Jeep is the worst about casting sand left over from the block molding process and Nitro is just another Jeep. Also, you dont need to go crazy with the air. Just hold it in the hose with a fairly firm grip and gently give it a little air till you get the feel of it. Anyone can do this job and on the hose clamps I used a pair of short channel lock pliars and be gentle while you twist the hoses off. Take your time. I spent 1 1/2 hours doing this and its new again. Have a great day friend.