My pool pump timer - intermatic, model #T104R3. was running fine. but 2 weeks ago we noticed it stopped clicking on. then we noticed it was running counterclockwise. is there a way to change it to run clockwise again?

Model number of timer is not known.
Is this new installation? Or installation that worked before and recently stopped working?
If the manual override lever on timer does not turn Load on-off, then 1) wiring is wrong or 2) timer has gone bad or 3) pump has a short.
I suspect a short since you say the pump 'tries to stop running.'
Copy following links for troubleshoot walk-thru, and correct wiring:
http://waterheatertimer.org/How-to-troubleshoot-Intermatic-timers.html
http://waterheatertimer.org/How-to-wire-T104-Intermatic-timer.html

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Sounds like 240Volt WG1573 clock motor has gone bad and needs replacement. But more checking is needed.

You posted under T2100-4R which is 60 amp Intermatic control panel with a single T104M 240Volt timer mechanism.
All Intermatic timer mechanisms can fit into same control center, so you can possibly have different timer mechanism inserted into the T2100-4R control center.
The control center can have up to 4 circuit breakers.
Instruction manual shows that timer can also have fireman's switch that is wired to pool heater and causes pool heater to turn off 20 minutes before pool pump turns off.
http://www.poolandspacontrols.com/products/mechanical%20controls/60%20amp%20pool%20and%20spa%20control%20panels.aspx

(1) First thing: If you have T104 mechanism, do a troubleshoot run-down to see if trippers, clock motor, or wiring are suspect:
http://waterheatertimer.org/How-to-troubleshoot-Intermatic-timer.html

(2) Next would be to check the circuit breakers for loose wires, burned connections, or the smell of burning or crackling sound that says breaker is loose on the busbar.

(3) Check for loose wiring on T104 and test circuit:
http://waterheatertimer.org/How-to-wire-T104-Intermatic-timer.html
(a) Push the manual override lever to OFF position and test across terminals 1 and 2 and then across terminals 3 and 4 to make sure timer is turning off power to pump. Both tests should show 0 volts.
(b) Push manual override lever to to ON position and repeat test above. Both tests should show 240 volts.
If the test fails, then buy new T104M timer mechanism.

(4) If the T104 timer is turning off both lines in the 240Volt circuit, then pump cannot turn on since neither wire is Hot.
However if your T104 timer is actually a T101 timer or if timer has different wiring, where timer is turning off only 1 leg and not both legs of 240Volt circuit, then pump has one hot wire available and a short to ground could cause pump to turn on unexpectedly.

T104R3 is ordinary 240V T104 timer mechanism inside a beige metal weathertight enclosure.
Put ON-OFF trippers on dial, lift and rotate dial until current time lines up with silver pointer.
Reset current time after power outage.
Open following links for T104 Instructions:
http://waterheatertimer.org/pdf/Intermatic-t104-240V.pdf
http://waterheatertimer.org/How-to-operate-and-set-T104-timer.pdf
Open following link if you have T104R201 with fireman's switch
http://waterheatertimer.org/pdf/Intermatic-T104R201-instruction-manual.pdf
http://waterheatertimer.org/How-to-wire-T104-Intermatic-timer.html

You might need $45 clock motor for for Tork 1101 120Volt.
http://www.frontierlighting.com/product.jsp?part=10431&process=search&show=&&gdftrk=gdfV22514_a_7c834_a_7c3267_a_7c10431

Open following link to identify timer and see replacement clock motor and trippers:
http://waterheatertimer.org/Tork-timers-and-manuals.html#1101

Intermatic crossover shows T101 timer replaces 120Volt Tork 1101.
Amazon sells new Intermatic timer for $45 with super shipping
http://www.amazon.com/Intermatic-T101-Hour-Dial-Timer/dp/B00002N5FN

Crossover wiring from Tork to Intermatic:
Black wire on Tork L and 1 connect to Intermatic terminal 1
White wires on Tork X connect to Intermatic terminal A
Black wire on Tork 2 connects to Intermatic terminal 2
http://waterheatertimer.org/How-to-wire-T104-Intermatuic-timer.html#T101

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1) You posted under T104 240Volt timer.
If I understand correctly the dial is not rotating, but manual override works fine.

2) Buy new T100 series WG1573 240V clock motor from Grainger
Also buy extra trippers since trippers wear down.
http://www.grainger.com/Grainger/timer-accessories/timers/electrical/ecatalog/N-8hi

3) Clock motor is located on back of timer mechanism.
Tip mechanism out by releasing thumb spring located top inside box.
Check motor number before ordering.
For example T103 timer looks the same as T104, but clock voltage is 120V.
Motor is held by 2 star screws > buy star screwdriver at auto parts or hardware.
On T104, the motor is connected to electric terminals 1 and 3.
T103, the motor is connected to terminals A and 1.

4) If you have different Intermatic clock motor, check links below:
http://www.aplussupply.com/intermatic/timermotors.htm
http://www.electricsupplyonline.com/prod/intermatic-motors.php

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I don't know if you have a 240V pump and 120V cleaner.
Or if both are 120V

T10000 series manual has troubleshooting
http://www.polytecpools.com/images/pdf/intermatic_t10000r.pdf

I specialize in timers.
If the manual override will not work and the circuit cannot be stopped by the timer:
Then the timer is bad.

To check for sure:
When pool pump is OFF, use tester and check voltage across terminals 1 and 2 on pump side
When cleaner is OFF, use tester and check voltage across terminals 1 and 2 on cleaner side

What test results show:
The cleaner side test across 1 and 2 should show no voltage when timer is OFF
The pump side test across 1 and 2 should also show no voltage when timer is OFF

If the pump side test across 1 and 2 shows voltage all the time, then the timer is broken.
There are no replacement parts for the internal on-off mechanism.



Polytec pools and spas sells the same timer for $215:
http://www.polytecpools.com/intermatic-t12404r-control-center-w220v-dual-timer-wo-breakers-p-543.html
BH electric shows the T10000 series for $178
http://www.beverlyhillselectric.com/t12404r.html

Add a comment if you need help wiring your new timer

You have what is called a 2-channel timer.
A single-channel timer can operate 2 or more Loads (pump, cleaner), but the Loads turn on-and-off at the same time.
A 2-channel timer has a clock (or digital program in the case of digital timers) so each Load turns on-and-off with a different schedule.

As a general rule, 2-channel timers are more expensive.
To avoid the higher price, you can replace a two channel timer with 2 ordinary timers.
Let me offer a replacement strategy that might save you money.
Keep the existing timer for the cleaner.
a) Buy Intermatic T-104R weatherproof timer if you have 240V pool pump.
b) Buy Intermatic T-101R weatherproof timer if you have 120V pool pump.
Here is a resource for the Intermatic timer I am suggesting:
The webpage has links to sellers, it has manuals and it has wiring diagrams for the do-it-yourself-er
http://waterheatertimer.org/How-to-wire-T104-Intermatic-timer.html

You probably need new 156T1978A tripper.
Trippers are made of softer metal and are designed to wear down and be replaced.
http://www.grainger.com/Grainger/INTERMATIC-Timer-Tripper-2E054?Pid=search

Open following link for troubleshoot checklist
http://waterheatertimer.org/How-to-troubleshoot-Intermatic-timer.html

The T104 timer is miswired when it does things like that. The 240 volt clock motor is internally connected at the factory to terminals 1 and 3. That means that one of the incoming (line) 240 volt wires (pick one) _must_ be connected to terminal #1 and the other _must_ be connected to terminal #3.

The outgoing (load) 240 volt wires are connected to terminals 2 and 4.

The Intermatic wiring diagrams leave a lot to be desired. I wrote the following tip to help clarify intermatic T103 and T104 timer wiring, I hope it helps:
http://www.fixya.com/support/r3734548-wire_intermatic_t103_t104_timers

You can try to tighten the wires connected, but more likely the contacts may have oxidized or burned. You can clean the contacts or replace the unit

'Line' means 'power in' and 'load' means 'output' to the device you want to control. Hook you power in 'HOT' wire to line and your 'load is the wires going out to the motor or lights or what ever. Follow the diagram on the door.

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