PMLCD Display Not Showing PMSHUNT Amps on PM335 Systems FAQ

1. Why is my PMLCD not showing amps from the PMSHUNT?

The PMLCD may not show current readings if the PMSHUNT/BM setting has not been enabled in the PM system settings.

Even if the PMSHUNT is physically installed and wired correctly, the PM335 system may only display battery voltage and state of charge until BM/shunt monitoring is turned ON.

2. Is this a fault with the PMSHUNT?

Not necessarily.

If the PMSHUNT is wired correctly but the PMLCD does not show amps, the issue is most likely related to system configuration rather than a faulty shunt.

The BM/shunt setting must be turned ON before the PMLCD can display charge and discharge current.

3. What readings should I expect once the PMSHUNT is working?

Once correctly enabled, the PMLCD should display real-time current values such as:

• Charging current
• Discharge current
• Load current
• Battery usage information
• More accurate battery state of charge information

The exact information shown may depend on the system firmware and display version.

4. Why does the system show battery voltage but not amps?

Battery voltage can be displayed without the PMSHUNT being active.

Current readings require the PMSHUNT to be installed, wired correctly, and enabled in the PM configuration. If BM/shunt monitoring is not enabled, the display may continue showing voltage but no amp readings.

5. How do I turn the PMSHUNT setting ON or OFF on the PMLCD?

On the PMLCD screen, the shunt setting is identified as “BM”.

Use the following steps to turn the BM/shunt setting ON or OFF:

1. Press and hold the PUMP and LOAD buttons together to enter the setup screen.
2. Press and hold the LIGHT button to enter the menu. You should see CLOC in the top-left corner.
3. Use the LOAD button to scroll down to the Module menu.
4. Press the LIGHT button to enter the Module menu.
5. Use the LOAD button to scroll to BM.
6. Press the LIGHT button to enter the BM menu.
7. The screen should display either 01 or 00:
   • 01 = BM/shunt ON
   • 00 = BM/shunt OFF
8. Use the LOAD button to change the setting to the required value.
9. Press the LIGHT button to confirm.
10. Press and hold the LIGHT button to return to the previous screen.
11. Press and hold the PUMP and LOAD buttons together to return to the main screen.

If a PMSHUNT is installed and required for current monitoring, BM should be set to 01.

If no PMSHUNT is installed and the system is showing Error 8901, BM may need to be set to 00.

6. Do I need to restart the system after changing the BM/shunt setting?

A restart may be required for the system to recognise the updated setting.

If current readings do not appear immediately after turning BM ON, turn the system off, disconnect power for approximately 30 seconds, then reconnect and check the display again.

7. Can I use a PMLCD-BTJ screen with a standard PM system?

No. The PMLCD-BTJ screen is designed for certain Jayco-specific systems and is not intended for use as a replacement display on a standard PM335 system.

It may communicate differently and may not support all standard PM control functions.

8. Why does the PMLCD-BTJ show amps but my standard PMLCD does not?

The PMLCD-BTJ may be able to read PMSHUNT data because it is designed for a different system configuration.

However, this does not mean it is fully compatible with the standard Projecta system. The correct solution is to turn ON the BM/shunt setting on the standard PMLCD, not to use the PMLCD-BTJ as a workaround.

9. Can the PMLCD-BTJ be used to configure the PM335 system?

The PMLCD-BTJ should not be used to configure a standard PM335 system.

Although it may display some information, it is not designed for standard Projecta system and may not communicate correctly with all system functions.

10. Why will the water pump not switch when using the PMLCD-BTJ screen?

The PMLCD-BTJ is not designed to control the standard PM system outputs in the same way as the standard PMLCD.

If the water pump does not switch when using the PMLCD-BTJ, this is likely due to display compatibility and control logic differences, not a water pump or PMSHUNT fault.

11. Which display should be used with the PM235, PM335 and PM435 systems?

The standard PMLCD designed for the PM335 system should be used.

Using the correct display ensures proper communication, system control, and compatibility with functions such as water pump switching and system monitoring.

12. What should I check if the PMLCD still does not show amps?

Check the following:

• BM/shunt setting is turned ON
• PMSHUNT is wired correctly
• Shunt is installed in the main battery negative line
• Signal wiring is connected to the correct terminals
• Battery capacity settings are correct
• Battery type is configured correctly
• Display firmware supports shunt monitoring
• System has been restarted after configuration changes

13. Where should the PMSHUNT be installed?

The PMSHUNT should be installed in the main battery negative line so that all charge and discharge current passes through the shunt.

If any loads or chargers bypass the shunt, the display may show incorrect or incomplete current readings.

14. Can incorrect wiring stop the PMLCD from showing amps?

Yes. Incorrect wiring can prevent the PM335 system from reading the PMSHUNT correctly.

Common wiring issues include:

• Shunt installed in the wrong location
• Battery negative bypassing the shunt
• Signal wires connected incorrectly
• Loose or damaged wiring
• Incorrect polarity

Always confirm wiring against the PMSHUNT installation manual.

15. Can firmware affect PMSHUNT operation?

Yes. Some older display or system firmware versions may not support all PMSHUNT functions.

If the BM/shunt setting is ON and the wiring is correct but readings are still not shown, confirm whether the PM335 system and PMLCD firmware support PMSHUNT integration.

16. Is the PMLCD not showing amps a hardware failure?

In most cases, no.

The issue is usually caused by one of the following:

• BM/shunt setting is turned OFF
• Incorrect wiring
• Incorrect display used
• Incompatible firmware
• System not restarted after configuration

Hardware replacement should only be considered after configuration and wiring checks have been completed.

17. Can lithium batteries be used with the PM235, PM335 ,PM435 and PMSHUNT?

Yes. Lithium batteries can be used with the PM335 and PMSHUNT if the system is configured correctly.

Ensure the battery type, battery capacity, and BM/shunt settings are correctly set so the display can provide accurate monitoring.

18. Why is the PMSHUNT important in a lithium battery system?

A PMSHUNT provides more accurate current monitoring than voltage-based battery estimation alone.

This is especially important for lithium batteries because lithium battery voltage can remain relatively stable over a wide state-of-charge range. The shunt helps provide a more accurate view of charge, discharge, and battery usage.

19. Should I use a third-party or Jayco-specific display for troubleshooting?

No. A third-party or Jayco-specific display may provide misleading results if it is not designed for the Projecta PM system.

Always use the correct Power management-compatible display and refer to the official system documentation.

20. What should I do if Error 8901 appears?

Error 8901 may appear if the system is looking for a BM/shunt module but the PMSHUNT is not installed or not detected.

Check the following:

• If a PMSHUNT is installed, confirm the wiring and set BM to 01
• If no PMSHUNT is installed, set BM to 00
• Restart the system after changing the setting
• Recheck the display for normal operation

21. What is the recommended fix if the PMLCD does not show PMSHUNT amps?

The recommended fix is:

1. Use the correct Projecta Power Management-compatible PMLCD.
2. Confirm the PMSHUNT is wired correctly.
3. Turn ON the BM/shunt setting on the PMLCD.
4. Check battery type and capacity settings.
5. Restart the system.
6. Confirm current readings appear on the display.