Where is the fuse to my 2 side mirrors and heated seat?

James,

Here's some sites that will help you...

https://www.google.com/search?q=driver+side+power+seat+on+2003+navigator+not+working

Best to you.

try running a fault scanner to reset the CPU program in the ECM

I think you are the victim of an otherwise good idea; theft protection that has disabled the electrical system.

I believe you will have better luck going to an MB forum and posting your question there:

Title goes here

Check all fuses with a 12 volt test lite

I believe your owners manual identifies what each fuse box location and fuse is for. Take a little time to read it and see.

probably a second fuse . the power seat alone requires 25 amp fuse

Not exactly.
According to the wiring diagrams, the heated seats are controlled by several fuses and two modules, plus two relays, along with input from the HVAC module. There is a module and a relay for each seat heater.
The mirrors are controlled by several other fuses and modules.
You may need a shop manual to trace the circuits.
All of the fuses involved are in the box in the engine compartment.

Instrument Panel Fuse Block
The instrument panel fuse block access door is
located on the driver side edge of the instrument panel.

Pull off the cover to access the fuse block.

The vehicle may not use all of the fuses shown.

Fuses Usage
1 Rear Seats
2 Rear Accessory Power Outlet
3 Steering Wheel Controls Back light
4 Driver Door Module
5 Dome Lamps, Driver Side Turn Signal
6 Driver Side Turn Signal, Stop lamp
7 Instrument Panel Back Lighting
8 Passenger Side Turn Signal, Stop lamp
9 Passenger Door Module, Driver Unlock
10 Power Door Lock 2 (Unlock Feature)
11 Power Door Lock 2 (Lock Feature)
12 Stop lamps, Centre High Mounted Stop lamp
13 Rear Climate Controls
14 Power Mirror
15 Body Control Module (BCM)
16 Accessory Power Outlets
17 Interior Lamps
18 Power Door Lock 1 (Unlock Feature)
19 Rear Seat Entertainment
20 Ultrasonic Rear Parking Assist, Power Liftgate
21 Power Door Lock 1 (Lock Feature)
22 Driver Information Centre (DIC)
23 Rear Wiper
24 Cooled Seats
25 Driver Seat Module, Remote Key less Entry System
26 Driver Power Door Lock (Unlock Feature)

There are 2 fuse blocks. The Power Distribution Center is under the hood along the passenger side fender and has fuses and relays in it. The other is on the passenger side of the dash and has fuses and circuit breakers.
....1994 Jeep Grand Cherokee Laredo
...(Fuse Block - Passenger side of Dash)
.....1........5........9........13........17........21........25
.20 A...15 A...20 A...20 A....7.5 A....15 A....30 A
.....2........6.......10.......14........18........22........26
.15 A...15 A...10 A...20 A.... 15 A....15 A....30 A
.....3........7.......11.......15........19........23........27
.20 A...15 A...15 A....3 A......15 A....15 A....10 A
.....4........8.......12.......16........20........24........28
.15 A...15 A...15 A...20 A.....10 A...7.5 A....30 A
1)Trailer Tow Relay
2)Brake Lamps
3)Hazard Lamps
4)Security Lamp
5)Interior Lighting
6)Security Alarm Module
7)Security Alarm Relay, Security Alarm Module, Flash-to-Pass
8)Overhead Console, Keyless Entry, Radio Memory/Clock
Memory/Chime Module, Power Locks, Power Mirrors,
HEVAC and VIC
9)Rear Wiper
10)Radio
11)Cigar Lighter
12)Parking Lamps, Automatic Headlamps
13)Horn Relay
14)Power Lock Relays
15)ABS Module and Relay
16)Turn Signals
17)Heating and Air Conditioning Module
18)Airbag Module
19)Interior Mirror, Auto Headlamps, Overhead Console,
VIC/GDM Module, Heated Rear Window Relay Coil,
Illuminated Entry Relay and Chime Module
20)Heated Rear Window Switch, Overdrive Switch, Speed
Control
21)Security Alarm Module, Lamp Outage Module
22)Airbag Module, Speedometer, Tachometer, Telltales and
Gauges
23)Heated Mirror Feed, Heated Rear Window Switch
24)Instrument Panel Illumination
25)Power Seats
26)Power Windows, Power Sunroof
27)Security Alarm Module and Front Wiper
28)Heated Rear Window Relay

i have a 05 ford f150 supercrew my power adjustable pedals didnt work my mirrors didnt work n the driver seat didnt work i found the problem i had a broken wire coming out of the #3 fuse block it it was orange with a green stripe it has some heat shrink on it i cut the heat shrink tape and the wire was badly corroded i replace the splice with 18 gauge wire and and everything came back on good as new