The wipers suddenly turned on at a constant speed and would not respond to the variable rate adjustment lever. I also noticed the click was missing when turning the switch in either direction. I unplugged the lever under the dash near the steering column and the wipers still continued to run. I suspect the turn signal/wiper switch has failed. I purchased another lever initially but didn't plug it in once the wipers continued upon diconnecting the old one.

I thought I may have connected a wire from the digital cruise control incorrectly when reinstalling it after disconnecting some of its wires. I connected the power wire and the wire from the digital cruise module that was supposed to connect to the OE cruise's red solenoid wire to B+ since the solenoid wire at the harness in the trunk didn't work for some reason. I'm in a rush and don't have time to identify the exact pins at the moment. I don't believe that had anything to do with it though.

There's rain in the forecast today also. That's just dandy.

Thanks in advance everyone.

What year and engine?

86 SE with cruise control.

The cruise control has nothing to do with the wipers. The wipers have nothing to do with the turn signals. There are three separate switches.

There are three conectors from the colunm. The tiny one is to the cruise. The longest one is to the turn signals. The medium one is to the wipers. The most common reason I have seen for the wipers to stay on is for the park switch to have failed in the motor. But if you are not feeling the clicks in the switch, you need to start there.

quote Originally posted by Electrathon: The cruise control has nothing to do with the wipers. The wipers have nothing to do with the turn signals. There are three separate switches. There are three conectors from the colunm. The tiny one is to the cruise. The longest one is to the turn signals. The medium one is to the wipers. The most common reason I have seen for the wipers to stay on is for the park switch to have failed in the motor. But if you are not feeling the clicks in the switch, you need to start there.

Without a wiring diagram the cruise control wiring was suspect because of the change in the feel of the lever. Whatever the case it was spontaneous and since unplugging the lever did not resolve the problem I suspected the switch.

Regardless, without a wiring diagram it certainly makes diagnosing more complicated.

U can download a factory service manual here: http://www.fieronews.net/fu...nloads.php?cat_id=13

Not sure how your cruise control could be tied in electrically to the wiper system, but if you have the wiper switch disconnected as you say, then the wiper motor should not work. However, 12 volts is still connected to the wiper motor, so I see one of few possibilities that could be the cause of your problems. First, you might have connected your digital cruise control to the wiper system, which is providing a run signal. Second possibility could be a bad delay wiper circuit board and the 3rd possibility is a stuck eletro/mechanical switch inside the motor.

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Nick D.
'88 Fiero GT 5-spd
'03 Jetta GLS TDI 5-spd

quote Originally posted by npdimonte: Not sure how your cruise control could be tied in electrically to the wiper system, but if you have the wiper switch disconnected as you say, then the wiper motor should not work. However, 12 volts is still connected to the wiper motor, so I see one of few possibilities that could be the cause of your problems. First, you might have connected your digital cruise control to the wiper system, which is providing a run signal. Second possibility could be a bad delay wiper circuit board and the 3rd possibility is a stuck eletro/mechanical switch inside the motor.

With no diagram and the sequence of events I made an initial assumption since both the cruise control and wipers have a connection to the switch. I suspected a possible misplaced wire damaged the circuitry at the switch causing colateral damage. I worked on the cruise the previous day but did not test it.

About 2 miles into my trip to work the next morning I had ECM/chip related problems that set a code while at the same time causing the car to run poorly. Just before I could pull off the road the wipers started up and would not shut off and I thought the lever felt a little different than what I recalled. That's why I suspected a wiring issue although the ECM issue turned out to be a programming error or possible problem with my emulator if it happens again. I noticed that chips after so many erasures will take a program and start out okay but shortly afterwards malfunction.

I'll take a look at the motor before tampering with the steering column as the wipers could have activated coincidently at that time which they had been doing lately and just developed a problem at the same time as the trouble that caused me to pull over in the first place.

Thanks, I'll take a look at the motor.

I will not know until I reinstall and test it tomorrow but I believe I've found the problem.







I don't know why the cirucuit failed at that point and it may fail immediatley again when tested. I recall it being tied in to the relay on the control board.

The repair of the open circuit affected wiper function but did not correct it. Fortunately continued searching revealed a thread by Luperman stating that the wiper switch from the 86 2.8L Chevy S10 can serve as a substitute in the Fiero. I'm pretty certain the switch is the problem given that the pre existing wiper swipe with key on digressed to ocassional spontaneous wiper swipes when the lever was bumped or used shortly before the constant on condition occured.

Many cars/trunks 84-94 years use it. see acdelco, look up part, view cars it fits.
still available new.
https://www.fiero.nl/forum/Forum2/HTML/121992.html

trace won't burn by itself... something else is bad. maybe motor has problems.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

I know from experience that when these control boards get wet, the wipers will go and not turn off. That indicates that the cause could be a a connection made that is not supposed to be made, rather than a connection broken. A capacitor gone bad will make a connection that would not otherwise be made. A diode gone bad will also. I suspect a bad part on the board.

quote Originally posted by TopNotch: I know from experience that when these control boards get wet, the wipers will go and not turn off. That indicates that the cause could be a a connection made that is not supposed to be made, rather than a connection broken. A capacitor gone bad will make a connection that would not otherwise be made. A diode gone bad will also. I suspect a bad part on the board.

Agreed but it doesn't make sense due to the parts arrangement, for the circuit board to fail spontaneously when not in use. On the other hand, when the action of bumping the wiper lever elicits a response (a new condition) indicating an extremely sensitive condition, chances are that parts inside it are already much closer than what they should be and when you add on the change in the way the wiper switch feels, for instance the stop point at the off setting apparently having disappeared at the same time as the incident, accompanied by what I've read, it has to be the switch. The board was not wet and there was no indication of any recent condensation. The car is parked in a garage over night. I have a diagnostic proceedure to run as the final word though.

It's kind of like brakes in this scenario, if the car shakes only when you apply the brakes, the problem is in the brakes not the tires.

Picked up a replacement motor and pulse board from a 95 S15, $25. Performed the diagnostic on both motors and both boards swapped across motors with the same result; With the center pins jumpered together at the board, the motor grounded and power to terminal A (white wire), if the motor is in park position nothing happens, if it is not in the park position, it returns to park.

If the above is confirmed Alldata states the switch is bad. I put the replacement motor in the car, turned the ignition to on, and plugged the motor in. I got the typical wiper swipe, the motor returned to the parked position (the previous motor would keep going) stopped and the fuse blew. The later pulse board looks more sophisticated and perhaps is sturdier blowing the fuse this time instead of the board supporting what Topnotch said about something else being responsible and causing the circuit failure in the board.

Next I'll replace the switch.

It was the switch. To recap the wipers started up and would not shut off. The phantom wipe with first power on was present but had recently started occuring intermittently while driving when the lever was bumped. When the fault occured the washer pump stopped working at the same time. The motor was tested by jumpering terminal B & D and connecting power to terminal A (white wire) which produced no response if the motor was in park position and returned the motor to the park position if it wasn't.

I plugged the new switch in and inserted a new lever into it, powered the ignition to find no phantom wipe, along with a functioning washer pump and properly working delay, Lo & Hi speed.

I believe the phantom wipe is a sign that there is a chronic low level load on the circuit board that over time can damage the pulse board if allowed to persist although it appears to take several years.

So if the board gets wet the wipers turn on.... maybe they were ahead of their time in coming up with moisture sensing auto wipers'

quote Originally posted by NetCam: So if the board gets wet the wipers turn on.... maybe they were ahead of their time in coming up with moisture sensing auto wipers'

That's what I hear, but my board wasn't wet. I did some experimenting with the extra plug that came along with the used motor and found that I could reproduce the chattering that started in the motor before a full swipe after repairing the first pulse board which suggested there was a problem with one of the resistors or grounding between one of the contacts in the switch, possibly allowing a higher than appropriate voltage to B or C since a brief 12 v connection caused a big spark but activated the motor which chattered for a second or so before doing a complete rotation.

Although I was able to get the old motor and pulse board to work outside the car in the test, it did have a tendency to do more than one rotation sometimes before parking suggesting that the pulse board sustained some collateral damage beyond the trace failure.

Finally got around to installing the new switch. It was a little more involved than I expected but no surprise. I had to remove the upper column support to get the harness out of the protective shielding and as a result didn't need a thread-wire to pull the new harness through.

My wiper problem was 3 fold. At the time the wipers turned on and wouldn't turn off, I was correct in noting that the click indicating wiper mode had disappeared. It turns out that it was because the wiper stalk about a year old had some how been damaged and had lost its grip on the stem, at the same time apparently the switch went bad damaging the pulse board which had a trace that was weaker than the fuse therefore blowing the trace instead of the fuse.

I confirmed the above when after discovering the stalk problem, I grasped the stem and turned the wipers to the off position. The wipers shutoff (replacement motor and pulse board in place at this time) and about a second later the fuse blew again as mentioned in an earlier post, indicating the problem had not been solved. Once the new switch and stalk were installed, the phantom wipe disappeared and wiper function returned to normal. The fuse was okay also.

Fiero switch on the left, 86 S-10 switch on the right, Autozone Part # SW946.

Im having some difficulties with my wipers as well, and i suspect the switch above may be my problem. Where excatly is it located?

quote Originally posted by blacknblue: Im having some difficulties with my wipers as well, and i suspect the switch above may be my problem. Where excatly is it located?

In the steering column which will have to be partially disassembled in order to remove it. There should be a thread with details on its removal.

[This message has been edited by Joseph Upson (edited 01-20-2013).]

Thanks, I've been searching the forum a lot to try to find it. Is it in the thread "inside the GM tilt steering column?" i just need some help pointing me in the right direction as i dont know much about this system.