Star Headlight & Lantern STAR-PA RSK966P - Manual (Page 15)

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(Troubleshooting Guide CONT’D)
5. Check each head. If the leads in one of the heads have shorted out, the output voltage
of the other heads may be held down as well. To test for this, unplug all of the heads
and plug them in individually (one at a time). If your problem is a result of a shorted
head, then each good head should function properly when connected by itself. Note: A
burned out strobe tube does not cause a short and will not affect the operation of the
remaining heads. If the problem is not with a shorted head and if proper voltage is
reaching the pack, the problem is most likely internal to the pack. Call Star to obtain an
R.M.A. number to return the pack for service.
Checking a Bad Power or Ground Connection
If sufficient voltage is not reaching the pack, perform the following tests:
1. Test Power at the Battery: With the vehicle turned off and while the pack is running,
measure the battery voltage at the battery. A nominal 13.8 volts should exist. If this
voltage is below 11.0 volts, the pack will not function properly and the problem is with the
battery. This reading should not be more than 1.25 volts higher than the reading at the
strobe pack itself.
2. Test the Power Wire Between the Battery and the Switch: Move to the ON/OFF
switch in the cab and gain access to the rear of the switch panel. With the vehicle not
running and the pack on at the high power setting, measure the voltage drop in the red
wire by taking a reading with one probe on the positive side of the battery and the other
probe in pin 1 of your switch. If this reading exceeds 0.25 volts then there is a poor
connection between the switch and the battery in the red wire and it should be checked.
NOTE: Excessive voltage drop may be occurring in the connections on the switch
panel. If you have one of our switches you can increase the contact pressure by
removing the FASTON terminal from the tab on the switch. Using long nose pliers,
gently squeeze the FASTON terminal together in the area that slides on to the tab of the
switch. This will increase the pressure applied between the tabs and the connector and
reduce voltage drop.
3. Test the Power Wire Between the Strobe Pack and the Switch: This same procedure
can be used to check the wires between the switch panel and the pack. Place one
probe on the terminal at the switch and the other probe into the terminal with the
corresponding wire color in the PWR connector on the pack. Once again, if any of the
readings exceed 0.25 volts then you should check those wires and their connections.
4. Test your Ground Wire: If you still have not located the problem, troubleshoot the
connections between the good chassis ground and pin 2 (black or blue wire) of the PWR
connector on the power pack. With the vehicle not running and the pack on at the high
power setting, measure the voltage drop in the Black (Ground) wire by taking a reading
with one probe on the negative side of the battery and the other probe in pin 2 of your
PWR connector. If this reading exceeds 0.25 volts then you have a bad Ground.