Does the truck have daytime driving lights ? Sounds like a short , maybe the switch inside the steering column . Turn signal , wiper , headlamp dimmer ,or multifuction switch . Without testing this is just a guess . Find a wiring diagram at
http://www.bbbind.com/free_tsb.html there free , get yourself a DVOM - digital volt ohm meter an test the B+ volt into an out of the switch . moving dimmer from low to high an turning on the turn signals etc.... Suggest you watch a few videos on youtube for automotive electrical testing , how to use a wiring diagram etc.... disconnect circuits at the mutifunction switch .
Measure the resistance between multifunction switch C202a pin 44, circuit 44 (LB), harness side, and electronic flasher connector pin 1, circuit 44 (LB), harness side; and between multifunction switch C202a pin 44, circuit 44 (LB), harness side, and ground.
- Is the resistance less than 5 ohms between the multifunction switch and the electronic flasher, and greater than 10,000 ohms between the multifunction switch and ground?
Carry out the multifunction switch component test;
Refer to Wiring Diagrams Cell 149 for schematic and connector information.
.
- Is the multifunction switch OK?
Yes INSTALL a new electronic flasher. TEST the system for normal operation.
No INSTALL a new multifunction switch; REFER to Section 211-05 . TEST the system for normal operation.
Testing the electrical circuits of all the system not functioning properly is how you go about finding the problem .
- Visually inspect the following for obvious signs of mechanical and electrical damage.
Visual Inspection Chart
Mechanical
Electrical
- Headlamp switch
- Multifunction switch
- Battery junction box (BJB) fuse 3 (30A)
- Central junction box (CJB) fuse:
- 5 (15A)
- 16 (20A)
- 26 (10A)
- 28 (10A)
- Wiring harness
- Loose or corroded connections
- Headlamp relay (if equipped)
- DRL relay No. 2 (if equipped)
- DRL jumper (if equipped)
- RAP module (if equipped)
- Central security module (if equipped)
- Light sensor amplifier (if equipped)
- Headlamp bulb
- If the concern is not visually evident, determine the symptom and proceed to the Symptom Chart.
Symptom Chart
NOTE: Refer to the Wiring Diagrams for connector numbers stated in the pinpoint test.
Symptom Chart
Condition
Possible Sources
Action
- Both headlamps are inoperative
- Battery junction box (BJB) fuse 3 (30A).
- Headlamp switch.
- Circuitry.
- Multifunction switch.
- The low beams are inoperative
- Central junction box (CJB).
- Circuitry.
- The high beams are inoperative
- CJB fuse 16 (20A).
- Circuitry.
- CJB.
- Multifunction switch.
- One low beam headlamp is inoperative
- CJB fuses:
- 28 (10A) (LH).
- 26 (10A) (RH).
- Headlamp bulb.
- Circuitry.
- One high beam headlamp is inoperative
- Headlamp bulb.
- Circuitry.
- The headlamps are on continuously
- Headlamp switch.
- Circuitry.
- Multifunction switch.
- Daytime running lamp (DRL) relay No. 2 (if equipped).
- DRL jumper (if equipped).
- Headlamp relay (if equipped).
- Remote anti-theft personality (RAP) module (if equipped).
- Central security module (if equipped)
- Light sensor amplifier (if equipped).
- The high and low beam headlamp is inoperative on one side
- REPAIR circuit 57 (BK). TEST the system for normal operation.
- The flash-to-pass feature is inoperative
- CHECK circuit 196 (DB/OG) for an open. REPAIR if necessary. If OK, INSTALL a new multifunction switch; REFER to Section 211-05 . TEST the system for normal operation.
×