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g6civcx · 05-01-2008, 08:14 AM

"stalk", not "stock". I was confused for a minute.

So your wipers always turn on to the highest speed with the key turned to ON, even if the wiper switch is turned to any position?

I suspect that your ground wire for the wiper motor is shorting out, causing the wiper motor to think that the switch is always turned to high.

When you turn the wiper switch to high, there is a wire that gets grounded. If this wire is shorted, the wiper motor will always move regardless of the switch position.

Also, there is automatic retract circuit. If you have the wiper at midstroke, and turned off the switch, the wiper will still return to base. This is controlled by a switch in the wiper motor that knows when the wipe is not at base, and a wire is grounded. The wiper amp will move the wiper at low speed until the wiper is back at base.

If the internal switch on the wiper motor is bad, it always thinks it's off base, and the wiper amp will always move the wiper trying to get it back to base.

Also, if the wiper amp is bad or if the wiring to the amp is bad, it will always move the wiper thinking that the wiper is off base.

There is an easy way to find out which is which. When the wiper moves, does it move at high speed or low speed? Compare with another S14 and see if yours is stuck on high or low.

If it's stuck on high, then you have a bad ground wire coming from the motor into the wiper switch and ground. Check for short by following the high speed ground wire from the motor all the way to the switch and grounding point. Check FSM for wire colour.

If it's stuck on low, then you may have a bad internal motor switch, bad wiper amp, or bad ground wire. Follow the low speed ground wire from the wiper motor, to the wiper amp and ground, and also to the wiper switch and ground. Check FSM.

There is also a possibility that your time control unit is going crazy, and causing the wipers to move by themselves. The TCU controls your variable wipers. I highly suspect this is the case, but if in doubt, unplug your TCU and see if it temporarily fixes the problem. Your other accessories that use the TCU may not work so don't drive around with the TCU unplugged.

05-01-2008, 08:14 AM	#3
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5)	"stalk", not "stock". I was confused for a minute. So your wipers always turn on to the highest speed with the key turned to ON, even if the wiper switch is turned to any position? I suspect that your ground wire for the wiper motor is shorting out, causing the wiper motor to think that the switch is always turned to high. When you turn the wiper switch to high, there is a wire that gets grounded. If this wire is shorted, the wiper motor will always move regardless of the switch position. Also, there is automatic retract circuit. If you have the wiper at midstroke, and turned off the switch, the wiper will still return to base. This is controlled by a switch in the wiper motor that knows when the wipe is not at base, and a wire is grounded. The wiper amp will move the wiper at low speed until the wiper is back at base. If the internal switch on the wiper motor is bad, it always thinks it's off base, and the wiper amp will always move the wiper trying to get it back to base. Also, if the wiper amp is bad or if the wiring to the amp is bad, it will always move the wiper thinking that the wiper is off base. There is an easy way to find out which is which. When the wiper moves, does it move at high speed or low speed? Compare with another S14 and see if yours is stuck on high or low. If it's stuck on high, then you have a bad ground wire coming from the motor into the wiper switch and ground. Check for short by following the high speed ground wire from the motor all the way to the switch and grounding point. Check FSM for wire colour. If it's stuck on low, then you may have a bad internal motor switch, bad wiper amp, or bad ground wire. Follow the low speed ground wire from the wiper motor, to the wiper amp and ground, and also to the wiper switch and ground. Check FSM. There is also a possibility that your time control unit is going crazy, and causing the wipers to move by themselves. The TCU controls your variable wipers. I highly suspect this is the case, but if in doubt, unplug your TCU and see if it temporarily fixes the problem. Your other accessories that use the TCU may not work so don't drive around with the TCU unplugged.