PRO-150 V1.0 11/18
Page 22
www.4qd.co.uk
11. Fault Finding
The Pro-150 has sophisticated self and environment testing so will find most faults
that are likely. If a fault if detected, the Pro-150 will shut down, will sound a pattern
of beeps, and display letters or numbers to indicate the nature of the fault found
[see table].
If nothing is shown on the display and no beeps are heard i.e. the Pro-150 is
completely dead, check;
1. The battery positive and battery negative wires are connected correctly
2. The two on-board fuse tracks are not blown, see Fuse tracks section.
3. Check the voltages on the back of the 6 way control connector. We have a
troubleshooting section on our website which gives full details.
Note: the display is powered from its own internal supply (derived from the
batteries, through the Pro-150) so that a dead display does not necessarily indicate
a dead Pro-150.
Fault codes with letters:
These are transient faults which will not damage the Pro-150 but do mean it will not
run. The display will show two letters while the fault persists and will resume
operation if the fault clears.
CL (Current Limit)
The on-board sounder emits a continuous series of beeps.
The Pro-150 has limited the motor current. This is not in itself a problem for the
Pro-150 and is included mainly as user feedback. However if such loading is
sustained for too long the Pro-150 may get hot and switch itself off.
HL (High pot Lockout)
The on-board sounder emits a continuous tone.
This occurs during power up tests if the throttle pot is not at zero. It will also occur if
the pot wiper is open circuit. HL will vanish when the problem is cleared.
Pt (Pot top)
The on-board sounder emits a series of 4 beeps.
This indicates a Pot or wiring fault or blown fuse track (F1) such that the voltage on
the top of the pot is high (above 4.7v) or low (below 2.5v). Check that F1 has not
been blown by a wiring fault.
It could also be a low or high resistance pot [1k>R>19k, a broken connection at
either end of the pot, or a short to the pot.
There are further details on the website knowledgebase.
The Pro-150 will operate normally again as soon as the fault is cleared.
