Heated wiper fluid light flashes rapidly

Vehicle information needed

Hard to say what's wrong without testing thing's . Is there B+ voltage to the wiper switch ? B + voltage to the wiper motor ? Do you know how to use a voltmeter ? How to test electrical circuits ?
Here is a factory service manual list of componets involved .
Wiper/Washer System Components
The Wiper/Washer System consists of the following electrical components:
• Accessory relay
• Heated washer nozzles w/XA7
• WASH NOZ 10A fuse
• Windshield washer fluid level switch
• Windshield washer pump motor
• Windshield wiper motor
• Windshield wiper motor module
• Windshield wiper/washer switch
• Wiper/washer switch 10A fuse
• Wiper motor 30A fuse

Do you know how the wipers work ?
Windshield Wiper Motor Wiring Tutorial
Wipers Inoperative - All Modes ?????
Wiper Motor Switch Troubleshooting

From your description it sounds like you need a new rear wiper motor. If I understand your description correctly. When you active the rear wipers, they work but when you press the same button, to turn them off. The wipers still continue to move. The wipers will turn off if you turn off the ignition key (when the wiper blade is in the parked position). and when you restart the van the rear wiper still stays off until you press and active the rear wipers. If I understood you correctly then I will suggest that you take a closer look at the rear wiper motor. If you have any other questions, please write back. I would like to hear from you and the progress you have made, good luck.

OK got your message on the other post (About the van) I am assuming that your Voyager is equipped with Automatic Climate Control. Follow the instructions below and you will get a better idea of what is wrong with your system.

Calibration/Diagnostics
1. To enter calibration/diagnostics test, set parking brake. Start and warm engine to normal operating temperature. With engine idling, turn blower switch to high. Turn mode switch to panel. Open all outlets. Move temperature to full cold.
2. Press and hold rear wash and rear wiper buttons simultaneously for 5 seconds (Until ALL LEDs illuminate). All LEDs should illuminate for 5 seconds. Rear wiper and intermittent rear wiper button LEDs will flash alternately during calibration/diagnostics test.
3. After approximately 60 seconds, if only the rear wiper button LED is flashing, calibration is successful and the system is okay. If rear wiper and intermittent rear wiper button LEDs are flashing, Diagnostic Trouble Codes (DTCs) are present. (See "Reading Diagnostic Codes" below)
4. To exit calibration/diagnostics test at any time, press the rear window defogger button, rear wiper button, or cycle the ignition off and then on. Test will automatically terminate 15 minutes after calibration/diagnostics is entered.

Reading Diagnostic Codes
1. Perform calibration/diagnostics test. If a DTC is present after calibration/diagnostics test has been performed, system will flash rear wiper and intermittent rear wiper button LEDs in sequence. Rear wiper represents code level, and intermittent rear wiper button LED represents code value.
2. Each time the rear wash button is depressed, rear wiper button LED wil cycle to the next code level in numeric sequence. After code level 5 is reached, rear wiper button LED will cycle back to code level 1. See table below.

The most common problem I find in this season, is having summer 32 deg. F freezing windshield wiper fluid in the tank rather than -20 deg. F freezing windshield wiper fluid.

Try to warm up the car by parking it in a heated garage until the windshield wiper fluid thaws. Then, try to use it all up, and add the 'winter' vs. the 'summer' formula of windshield wiper fluid.

If this does not solve the problem, the pump might be burnt out, in my experience.

You should hear a humming sound as you depress the button for windshield wiper fluid inside of the car.

Good luck on this repair.

You need to recalibrate the climate control system.

• Start the van.
• Slide the temperature lever all the way to the left (full cold).
• Turn the Mode Control to 'panel' (the one that sends air to your face only).
• Turn the 'blower switch' to all the way to full.
• Now go to the leftmost three buttons. Press and hold the top one (rear wiper on constant) and the bottom one (rear wiper washer fluid) until the lights come on solid then begin to flash, and then you can let go.
• The AC will now calibrate. You will feel the air blow out of all the different zones at different intervals and see lights come on and go off. Then after a minute or two the top button you pressed will be slowly flashing. This means it has been completed.
• Press the last flashing button and you are done.

Here are the following options for activating a rear wiper.

Push button the dash
Pull the wiper lever back (may activate washer fluid on some cars)
Push the wiper lever forward (may activate washer fluid on some cars)
Twist the wiper lever
Push the wiper lever tip if it has a button (may activate washer fluid on some cars)

To Calibrate , start and warm engine to normal operating temp. with engine idling turn blower switch to high, turn mode switch to panel, open all outlets, move temp lever to full cold.
press and hold rear wash and rear wiper buttons simultaneously for 5 seconds (untill all leds illuminate.) all leds should light up for 5 seconds, rear wiper and intermittent rear wiper button leds will flash alternatly during calibration... after 60 seconds if only rear wiper button led is flashing, cal. is complete

This means there are body codes stored in the computer.

Sounds like its gone into programming mode. All you need to do is start your van. (if you are unsure what knob or lever is which I am looking in the manual for proper terms) Then slide your temp lever all the way to the left (full cold). Then turn the Mode Control to 'panel' (the one that sends air to your face only). Then turn the 'blower switch' to all the way to full. Now go to the leftmost three buttons. Press the top one (rear wiper on constant) and the bottom one (rear wiper washer fluid). Hold these two for a few seconds. Once the lights come on solid then begin to flash you can let go. The AC will now calibrate. You will feel the air blow out of all the different zones at different intervals and see lights come on and go off. Then after a minute or two the top bottn you pressed will be slowly flashing. This means it has been completed (I actually let it run for 5 more minutes just in case something else started blinking). Press the last flashing button and you are done.