Electrical problem My headlights, parking lights, tail lights, fog lights, interior lights, dash lights and power door locks suddenly all quit working and it says Service FWD on the information panel. I could not find any blown fuses in the cab or under the hood. The engine runs fine and everything else, radio, power windows, ac, blower, stop lights, turn signals all work. my headlights,dashlights,domelights,fwd all quit working i unplugged the battery and plugged it back in and they work but they all flash off and on and the door buzzer wont stop and my dome lights wont shut off my wipers come on by themselfs my doorlocks click all the time and my horn will honk by itself

Ck the fuses here is the info if you already haven't.
1-Headlight washer jets
2-Turn signal flasher
3-Headlight washer, glove box light, engine bay light, instrument cluster
4-License plate lights
5-Instrument cluster, heated seats, auto trans display, outside air temp
6-Central locking system
7-ABS
8-empty
9-heated mirrors
10-empty
11-cruise control(auto trans)
12-on board diagnostic system
13-brake lights
14-interior lights
15-power windows, climate control
16-ABS, anti-slip(?)
17-heated door locks
18-right high beam
19-left high beam
20-right low beam
21-left low beam
22-tail and side marker (right)
23-tail and side marker (left)
24-wipers and washer jets
25-blower for heating/climate control
26-rear window defogger
27-empty
28-fuel pump
29-engine timing
30-sunroof
31-tail lights, cruise control, auto trans
32-engine timing
33-cig lighter
34-engine timing
35-trailer receptacle(?)
36-fog lights
37-radio
38-trunk light, central locking system
39-flashers
40-horn
41-empty
42-empty
43-heated seats

Ok there's the numbers. To figure out what the hell that means you have to look at the inside of the cover to the fuse box. left side of dash panel. Good luck.

The Central Timer Module (CTM, called BCM on some vehicles) supports or controls:
Automatic door lock/central locking
Battery protection
Chimes
Exterior lights (park lamps, fog lamps, headlamps)
Interior lights
Intermittent wiper control
Power lock control
Remote keyless entry (RKE)
Vehicle Theft Security System (VTSS)
Remote radio control (from steering wheel)

It covers all the problems you described except the 4WD controls. I suspect you may want to have the CTM checked, or do like I did and just replace it (used about $75-$100 on eBay). Make sure you get the part number on yours and match the number portion (not necessarily the two letter suffix) EXACTLY.
It should be located behind the kick panel to the left of the driver's feet (that's where it is on my 2003 Dakota), but may be to the right of the glove box (have to remove the glove box to get to it).

You have a short to ground somewhere in the drl-fog lamp circuit. Check for obvious wiring connector or wiring to drl & fog lamps. check wiring for pinched or broken wires coming from sockets. If you don't find problem, you can trace wiring from lamps to main harnesses and hopefully find source of short.
hope this helps.

Fuse Locations & Functions
1. Washer nozzle heaters, glove compartment light (10A).
2. Turn signal lights (10A).
3. Fog light relay, instrument panel light dimmer switch (5A).
4. License plate light (5A).
5. Comfort system, cruise control, A/C, steering wheel module (7.5A).
6. Central locking system (5A).
7. Back-up lights, speedometer vehicle speed sensor (VSS) (10A).
8. Open
9. Anti-lock brake system (ABS) (5A).
10. Engine control module (ECM): gasoline engine (10A)
11. Instrument cluster, shift lock solenoid (5A).
12. Data Link Connector (DLC) power supply (7.5A).
13. Brake tail lights (10A).
14. Interior lights, central locking system (10A).
15. Instrument cluster, transmission control module (TCM) (5A).
16. A/C clutch, after-run coolant pump (10A).
17. Open.
18. Headlight high beam, right (10A).
19. Headlight high beam, left (10A).
20. Headlight low beam, right (15A).
21. Headlight low beam, left (15A).
22. Parking lights right, side marker right (5A).
23. Parking lights left, side marker left (5A).
24. Windshield washer pump, windshield wiper motor (20A).
25. Fresh air blower, A/C (25A).
26. Rear window defogger (25A).
27. Motor for rear windshield wiper (15A). (if equipped)
28. Fuel pump (FP) (15A).
29. Engine control module (ECM) gasoline engine (15A)
30. Power sunroof control module (20A).
31. Transmission control module (TCM) (20A).
32. Injectors: gasoline engine (10A)
33. Headlight washer system (20A).
34. Engine control elements (10A).
35. 12 V power outlet (in luggage compartment) (30A).
36. Fog lights (15A). (if equipped)
37. Terminal (86S) on radio, Instrument cluster (10A).
38. Central locking system (w/ power windows), Trunk light, fuel door, Trunk lid (15A).
39. Emergency flashers (15A).
40. Dual tone horn (20A).
41. Cigarette lighter (15A).
42. Radio (25A).
43. Engine control elements (10A).
44. Heated seats (15A). (if equipped)

Fuse arrangements in fuse bracket/battery:
S162. Glow plugs (coolant) (50A).
S163. Fuel pump (FP) relay/glow plug relay (50A).
S164. Coolant fan control (FC) control module/coolant fan (40A).
S176. Relays panel interior (110A).
S177. Generator (GEN) (90 Amp.) (110A). Generator (GEN) (120 Amp.) (150A).
S178. ABS (hydraulic pump) (30A).
S179. ABS (30A).
S180. Coolant fan (30A).

The relay has nothing to do with the tail lights, but replacing the switch sounds like a good idea. There's a nut holding it in place, see http://www.skandix.de/en/spare-parts/electrics/switches/switch-headlight/1027524/ to get an idea of the construction. And the price. This is not worth fiddling about unreliable workarounds...
In addition, if fuses 15 and/or 16 burn frequently there might be a problem with the tail light cabling.

Good luck
Ingo

Fuse is probably blown out. Replace fuses for respective functions. Find the fuse box: might be in engine near battery or below steering wheel. open top and check for blown fuses. Try replacing if blown fuses are found. If all fuses are OK then it is very unlikely that all the bulbs are blown.

Having the same issue somewhat. Tail lights and dash lights quit. Checked the headlight switch wiring harness by looping all other prong holes back to the main power and they all work, so mine must be the switch. Having a real hard time finding a switch that matches the old one, even though they say it is a replacement. I paid the $25 at www.alldatadiy.com and they have quite a few wiring diagrams for the car.

where is the dome light bulb located?

It turned out that disconnecting the battery and reconnecting it reset the control module and fixed the problem.