New Holland CX720 Repair Manual page 1351

E0136-04-Beacon Lights Switch Shorted to Low Source
(A.40.A.15.83 - G.30.B.53)
E0136-04 - Beacon Lights Switch Shorted to Low Source
Cause:
The beacon light switch (S-41) circuit is shorted to ground.
Possible failure modes:
1. Switch supply wiring shorted to ground.
2. Controller internal failure (internal regulator failure).
Solution:
1. Enter the InfoView Monitor - "Diagnose info" screen.
Select "Electrical" sub menu.
Select "Beacon lights switch" and check voltage range. Cycle the beacon light switch between the On and Off
positions.
The normal operating range for the beacon light in the "Off" position is 0.5 - 3.5 volts.
The normal operating range for the beacon light in the "On" position is 3.5 - 5.0 volts.
NOTE : The beacon light switch actually supplies 12 volts (battery voltage) to the module when in the On posi-
tion, however, the Diagnostic screen bar graph only displays to 5 volts.
A. If the voltage reading is low (0 - 0.5 volts) continue with step 2.
B. If the voltage reading is within the proper limits continue the troubleshooting at step 5.
NOTE: Visually inspect the wiring harness and connectors. Verify that the connector was fully installed. Inspect
the terminals and wires at the connector for pushed back or corroded terminals or damaged wires. Flex the
harnesses involved to reveal intermittent breaks or shorts in the wiring concerned.
2. Check fuse F-49.
A. If fuse has failed, continue with step 3.
B. If fuse is okay, continue with step 4.
3. Replace fuse F49.
A. If fuse immediately fails, there is a short to ground on one of the following wires in the cab main (CM) or
cab roof (CR) harnesses:
Wire 046 orange, fuse F-49 through connector X073 to seat switch S05
Wire 045 orange, fuse F-49 through connector X002 pin A to cab roof harness splice
Wire 901 orange, harness splice to HVAC module connector X128 pin C2
Wire 240 orange, harness splice to rear work light switch connector X132 pin 2
Wire 172 orange, harness splice to beacon light switch connector X130 pin 2
Wire 124 orange, harness splice to tank extensions switch connector X125 pin 2
Wire 239 orange, harness splice to rear work lights switch connector X131 pin 2
Locate the short to ground and repair.
B. If fuse is OK, continue with step 4.
4. Place the beacon light switch in the ON position.
A. If fuse immediately fails, there is a short to ground in the cab main (CM) or cab roof (CR) harnesses
between the beacon lights switch connector X130 pin 3 through connector X002 pin M to connector X015
pin J1-2 wire 166 yellow. Locate the short and repair.
B. If fuse is okay, continue with step 5.
5. Operate the machine while monitoring Infoview display. If no low out of range readings are indicated, erase the
fault code and continue operation.
DISTRIBUTION SYSTEMS - LIGHTING SYSTEM
2 4/7/2006
A.40.A / 35