Controller has single flashing red light. how to correct fault ?

if the red light is flashing this means theres a fault , most common fault on these are water catch bucket is full or not seated back correctly

http://www.kidde.com/Documents/User-Guide-900-0102-A-ENG.pdf Remember that smoke take presidence over C/O detection so notice whats going off first . LED Indicator Operation
Red LED
The red LED will flash as described below under the following
conditions:
--During smoke or CO alarm, with every beep
--During testing (same as alarm)
--Low battery, single flash with chirp
--End of product life, double flash every 30 seconds with chirp
--Unit error mode, single flash with chirp
--Unit error mode, a Fault Code is flashed every 30 seconds (can
be observed and reported to customer service for
troubleshooting. Above is the user guide.

Possible that the suspect could be the controller board, you can switch the machine off power for sometime, check the power outlet for the correct voltage. If not the front panel must be removed to check on the board and a possible fault of the processor or memory.

According to my 1170 manual the flashing lights are error codes. 1 red = low batt., 2 red = left motor disconnected, 3 red = Left motor wiring fault, 4 yellow = Right motor disconnected, 5 yellow = right motor wiring fault, 6 yellow = Inhibit active, 7 yellow =possible joystick fault, 8 green = possible controller fault, 9 green = Solenoid brake fault, 10 green = high batt. voltage

There is a connector but it is not like the connector used in the newer 1996 OBD2 cars, your year uses OBD1, here is how you check for codes in this car.

Acura OBD1 Codes Retrieval
Acura vehicles 1986-95 obd1 code retrieval
There are a few different ways to retrieve the codes for "check engine light" for Acura vehicles. One method is to use a led light (sometimes 2 led lights) on the computer or controller box itself. If it has 2 led lights, the color is red and amber. The red is used for flashing the codes whereas the amber is used for adjustment. If you have only a single led light indicator, then that is used for flashing the code.
The controller box can be found by lifting the carpet of the passenger side front foot well or floorboard. You can see the led lights without removing the controller. On other models, you can find the controller under the driver or passenger front seat.
The second way to get the code is using a jumper wire on the diagnostic connector located on the kick panel at the front passenger side. You then watch the codes being flashed at the dash panel after you turn the key on. To read the code being flashed is easy. Example: Code 23 is 2 long flashes followed by 3 short flashes. A longer pause separates the next code that follows.
Here are Acura vehicles 1986-95 general codes:
Code 0 Electronic control unit (ecu)
Code 1 02 (oxygen) sensor
Code 3 and 5 map sensor
Code 4 Crank angle sensor
Code 6 Coolant temperature sensor
Code 7 Throttle angle sensor
Code 8 Crank angle sensor (TDC)
Code 9 Crank angle sensor (CLY)
Code 10 Intake air temperature sensor
Code 12 EGR system fault
Code 13 Atmospheric pressure sensor
Code 14 Electronic air control valve
Code 15 Ignition output signal
Code 16 Fuel injector fault
Code 17 Vehicle speed sensor
Code 21 Spool solenoid valve
Code 22 Valve timing oil pressure switch fault
Code 23 Knock sensor
Code 41 Oxygen sensor heater fault
Code 43 Fuel supply system

You have a module problem:

Evaluate your batteries. 12v Single or 24 together.
Flash codes:
1. Stall Timeout, Joystic out of neutral
2. Battery Voltage too over 32VDC hi or too low under 17VDC
3. Left motor Fault
4. Right Motor Fault
5. Left Brake Motor fault
6. Right Brak Motor fault
7. Shark Control Module Faul
8. Power Module Faul
9.Shark Module Faul

I answer questions for free.
I specialize in timers and electrical devices

Below is the manual for the EJ351
http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/ej351c%20-%20english.ashx
The red light is a good indicator of the EJ351 timer.
The manuals says that you can clear all programming by moving control lever to OFF-CLEAR position for 20 seconds.
After programs are cleared, the red light will turn off.
Then move control lever to ON position, and then red indicator light will start flashing.
So the problem may be that the timer programs were accidentally cleared.
Use the instruction manual to re-program your timer.
Add a comment if you need more assistance, and I will help.

Hi. Count the flashes between the pauses, it is a fault code. Try putting free-wheel lever in the correct place. Different numbers of flashes mean different faults. Let us know. Good luck. Neil.

use this site and put 220 in the search box - your explorer 220 is found and you can download the user guide http://www.plantronics.com/north_america/en_US/support/manuals.jsp;jsessionid=83D442E12D37E83038D66C83670075A9.delta#results
see page 14 for details of the lights

• Powering on Blue flashes
• Powering off Red appears and goes off.
• Charging battery Red solid light.
• Low battery Red flashes.
• Pairing mode Blue/red flashes.
• Missed call Purple flashes. Single press the call control button to cancel.
• Ringing Purple flashes. Briefly press call control button to answer the call.
• Press call control button for 2 seconds to reject the call.

had same problem, first you need to find the location of ignitor double black wires from plug on board and flame sensor.single red wire. 4 red flashes means ground fault, I removed ignitor, cleaned with some scothchbrite, cleaned around screw holes(2) to reestablish ground, I even ran a wire from one of the mounting screws to a ground elsewhere. then I went on to the flame sensor witch will give you flashing yellow light. single red wire to sensor that has one screw holding in. Remove sensor carefully and do the same as the ignitor, clean with scothbrite. I did this a year ago and is still going!