Question about Malibu ML600TW - Low Voltage Power Pack - 600 Watt - With Timer and Ground

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The transformer will work if I manually turn the dial. The dial will not automatically turn anymore.

Posted by jowesfas on


1 Answer


If the bulbs turn on when you manually rotate dial, then the power pack has electricity.
A lot of people ask for replacement Malibu tripper pins on Fixya, and it sounds like your trippers are working fine.
If clock has stopped rotating, that means the power pack has malfunctioned, and needs to be replaced.

I did find some tips to help folks preserve their power packs:
1) Match wattage of bulbs with wattage of power pack
-15 each X 20 watt bulbs = 300 watts, so install 300Watt power pack
2) Installing a 500W power pack on 300W of bulbs will burn out bulbs and power pack.
3) Replace bulbs as soon as they burn out or other bulbs will burn out and power pack will burn out.
4) When working on bulbs, unplug power pack or it may burn out.

Posted on Nov 12, 2010


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How do I set automatic timer on AC1 Hozelock watering system?

incorrect operation. 1. Remove screws and back cover. 2. Insert two 1.5V 'C' Alkaline batteries. (Check + and - are correct.). IMPORTANT: Rechargeable batteries must not be used. 3. Replace batteries each season. (max 12 months use) MAINTAINING THE WATERPROOF SEAL 1. Ensure that rubber seal is positioned correctly. 2. Replace back cover and screw down tightly. 3. Repeat each time back cover is removed. HOW TO PROGRAMME THE TIMER There are two watering operations - Automatic and Manual. AUTOMATIC OPERATION Automatic ON 1. Turn dial clockwise to AUTO START at actual desired start time (e.g. To start watering each day at 15H00 you must set your AC1 when the actual time of day is 15H00). The timer has now memorised the auto start time until it is reset and will operate every day at this time. Use of manual ON or OFF does not cancel memory. 2. Turn dial anti-clockwise to: a) Chosen duration for once-a-day operation, or b) Chosen programme for all other watering frequencies (see table). The timer will now automatically run the selected program repeatedly until a new option is selected. GB 2 Automatic OFF Turn dial to Manual ON or OFF. If you wish to return to Automatic watering re-select the desired watering programme. NOTE your auto start time remains memorised until a new one is selected. Changing start time Turn dial clockwise to AUTO START at new chosen start time. Changing watering programme Turn dial to new programme. Do not turn dial to AUTO START unless a new start time is desired. MANUAL OPERATION Manual ON Turn dial anti-clockwise to ON. Water will flow for 60 minutes maximum or until turned to OFF setting. Note: After 60 minutes water shuts off. Knob will still point to ON and needs to be manually set to OFF or to desired number of automatic watering minutes. Manual OFF Turn dial clockwise to OFF. Note: Operation is only audible when valve opens and closes. To check that timer is working, switch to manual ON or OFF to hear valve operate. CONNECTING THE TIMER TO THE TAP Use supplied adapters if required. Tighten to ensure no leaks

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1 Answer

Intermatic dial doesn't automatically switch sprinklers

1) Trippers can wear down. Transformer can go bad if model has 24Volt output. Relay can go bad.

2) Add a comment Feb 2013 with model number, and include if this is new timer or older timer that worked before and stopped working.

If you need further help, I’m available over the phone at

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1 Answer

Malibu transformer ml44p doesn't turn off

Check if trippers are worn.
Check if dial rotates and keeps good time.
Plug transformer into cheap wall timer.

Copy following link for trippers, 5-year warranty info, tips to make power pack last longer, and other troubleshoot resources:

If you need further help, I’m available over the phone at

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1 Answer

Lost manual for ML300RTW transformer. Does this transformer have an override so I can plug into exterior timer? If so, where is it?

Yes power pack has override, depending on model.
There should be a small knob located above and to left of dial that rotates: Step 8 in Manual says: You can manually operate the lights by turning the Manual ON/OFF Switch counter clockwise.

For information on Intermatic/Malibu power packs showing links to manuals, troubleshoot steps, replacement trippers, useful links, warranties and tips:

Add a comment with your experience so others with same-similar problem can benefit.

Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

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1 Answer

The timers on my Intermatic Timer T40003RT3 are not working. I can turn the pumps on manually with the switch below the timers but the dials themselves are not turning, preventing them to turn on &...

Sounds like clock motor(s) are working.
Snap mechanism out using thumb spring located inside top of box.
Look for clock motor number printed on clock, should be WG1573 for 240V timer

Google search for 'Intermatic WG1573'
For example Grainger sells that clock motor as 1PNK2
(plus they sell extra trippers which are designed to wear down):

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

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Cycle dial doesn't advance automatically anymore. I saw some listed problems that sounded similar, but not exact. Washer will work in all cycles, but only when I watch and move the dial manually.

Hello & Welcome to FixYa

Its seems that the Timer is stuck, as everything else is working fine in the unit and the dial ust gets stuck and so won't complete the cycle so the problem is with the Timer motor going bad and needs replacement. Please get back to me if you have any other questions.


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1 Answer

I just purchased Malibu ML 600 TW transformer, and ran wire and attached lights, but I can't get any of them to work. Perhaps I'm wiring it incorrectly? How do I test the transformer to see if it is...

Malibu website
Malibu manuals

The power pack has a humming sound >> put your ear close
Plug in a hair dryer on same plug to see if you have power
Check the GFI tripper in bathroom and kitchen
Plug power pack directly into receptacle (no extension cord)
It is hard to believe you got every light wrong >> the light connections are pretty fail-proof today

1) You can test the transformer by rotating manual override counterclockwise >> that's the on-off switch
2) You can test transformer by seeing if clock dial rotates with passing time > the clock must rotate
3) You can check if wires have power > disconnect wires > use another wire to scratch across both terminals to see if there is a spark

4) Did you put the red-and-black tripper pins on the dial? Red = ON Black = OFF

5) I think you forgot to set the time of day correctly
- put in tripper pins.
- rotate center dial clockwise to present time
- now, rotate dial two more full rotations and come back to present time

If the dial will not rotate or transformer does not have power, then the transformer is defective.

Oct 09, 2010 | Malibu ML600TW - Low Voltage Power Pack -...

1 Answer

Lights will turn on and off manually only

Just checking, still plugged in, fuse or circuit breaker not tripped that provides power to it? If you can turn it manually, and the dial does not turn when powered up, look for a small on/off switch, other than that, maybe it does need replacement, but they usually last longer that a year, but I have had some timers that just quit working on me too.

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2 Answers

TV Turns off automatically

Could be a problem with the flyback /auto transformer / powerboard. I'd get those checked first..

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