Checking The Key Switch - Wacker Neuson RD 12A Repair Manual

Honda Engine Starting System
3.3

Checking the Key Switch

Prerequisites
Multimeter
Fully-charged (approximately 12V) battery
Functioning 20A main fuse
Background
The key switch is a three-position switch: ON, START, and OFF. When in the START posi-
tion, the key switch directs battery voltage to the crank relay.
Procedure
Follow the procedure below to check the key switch.
1. Remove the screws that secure the plate (a) to the back of the control panel and remove
the plate.
2. Using the multimeter, check the voltage between the BAT terminal (b) of the key switch
and ground. For easier measuring, remove the plug and measure voltage at the plug.
Is battery voltage (approximately 12V) measured?
3. Place the key switch in the START posi-
tion.
4. Re-install the plug to the key switch.
5. Check the voltage between the "S" ter-
minal (c) of the key switch and ground.
Is battery voltage (approximately 12V) measured?
6. Re-install the plate to the back of the control console.
The key switch has now been checked.
wc_tx000693gb.fm
Yes ____
Continue Check the continuity of red wire #13 between the key switch and
Yes ____
The key switch is OK.
No ____
20A main fuse. Repair red wire #13 as needed.
The key switch has failed; replace it.
36
RD 12/RD 12A
No ____