When I go to start my '87 GT, my windshield wipers go through one cycle. They're not on so is this a problem most likely in the turn signal stalk?

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario

wiper stalk or more accurately the switch in the collumn is usually that they turn on when you hit the turn signal.. no i suspect its the control board thats built into the motor - rodney dickman sells a repair kit - or you can just buy a new motor - only takes about 15 minutes to swap out the motor

[This message has been edited by Kohburn (edited 01-12-2006).]

I think that you will find the problem to be in the wiper switch in the steering column. I have changed three different boards in the motor with no difference, So I am convinced the problem is in the wiper switch which is expensive and hard to replace. Also I have asked before and received no replies. Does anyone with just plain wipers and no intermittent wipers ever had this phantom swipe. I think you only get it with the intermittent wipers
Don

[This message has been edited by ka4nkf (edited 01-12-2006).]

Thanks for the replies. I think I'll replace my turn signal stalk anyway. It's cracked. Can't help out on the non-intermitant wipers. Never had a Fiero without them. But if replacing the turn signal arm doesn't work, then I'll try the wiper motor itself. The only bad part about it is that if I have a lot of stuff from the overhanging trees on my windshield, the wipers end up dragging across it before I can get it washed or blown off. It drastically shortens the life of my wiper blades.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario

I can assure you that replacing the turn signal stalk will not fix the phantom swipe.
Don

[This message has been edited by ka4nkf (edited 01-12-2006).]

Perhaps not. But it needs to be replaced anyway. So it'd at least rule that possibility out.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario

Mine did the same thing - single cycle, any time I started the car cold.

I replaced the entire wiper motor/circuit board assembly/unit, and (knock on wood) it's been fine ever since.

(I was glad, too, 'cuz I didn't want to dig into the steering column.)

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Patrick W. Heinske -- LZeitgeist@aol.com
1988 Red Fiero Formula Convertible
*Desktop Photo Here*

There's two different failures that'll cause the problem you're seeing.

- A bad delay wipe pulse board will do it.
- A bad wiper switch will also do it.

If it happens every time you start the car and only one wipe each time, I'd strongly suspect the pulse board.

quote Originally posted by Whuffo: There's two different failures that'll cause the problem you're seeing. - A bad delay wipe pulse board will do it. - A bad wiper switch will also do it. If it happens every time you start the car and only one wipe each time, I'd strongly suspect the pulse board.

I agree
Also don't you think that if they had run the 12 volt to the stalk instead of having it hot at all times when the ignition is turned on? This would eliminate the ghost wipe.
Don

quote Originally posted by ka4nkf: I agree Also don't you think that if they had run the 12 volt to the stalk instead of having it hot at all times when the ignition is turned on? This would eliminate the ghost wipe. Don

The downside to that is that the pulse wipe circuit draws a small amount of current at all times; not a problem if it's only powered with the key on, but if it was on all the time it'd run the battery dead over a few days.

quote Originally posted by Whuffo: The downside to that is that the pulse wipe circuit draws a small amount of current at all times; not a problem if it's only powered with the key on, but if it was on all the time it'd run the battery dead over a few days.

I really don't understand what you mean. What I say is the wiper motor board gets 12 volts when the ignition is turned on. This is why the pulse board is giving the swipe when first turn of the ignition. If the wiper did not get any power until you turned the stalk on for wipers, then you would not have a phantom swipe. The stalk would be the switch instead of the stalk making contact with 12 volts through the wiper switch. Anyway I am not very good at explaining, but I know what I am trying to say Thanks
Don

quote Originally posted by whadeduck: Perhaps not. But it needs to be replaced anyway. So it'd at least rule that possibility out.

Just for reference, the stalk doesn't have any wiper switch functions in it. The wiper switch is actually inside the column, the stalk's steel shaft just plugs into it.

Generally, if moving the steering wheel, bumping the column or stalk, or other activity at the column triggers the phantom wipe then the problem is likely with the switch. The contacts in the switch wear over time and become contaminated with metal powder mixed with grease. The other common cause of phantom wipes is bad capacitors on the delay board on the end of the wiper motor, Rodney sells an economical repair kit for that problem.

JazzMan

[This message has been edited by JazzMan (edited 01-12-2006).]

Here's what JazzMan was mentioning. Jazz I'm sure you have your own pics, but just in case.

The stalk just fits in the switch

This is what inside the switch looks like after 20 years

Edited for spelling

[This message has been edited by rubyredfiero (edited 01-13-2006).]

Does anyone have the part number for that switch?

I went to my local GM dealer, told them what I wanted, and they sold me part number GM 1997988
it doesn't even remotely look like the one in the pic.
I have never been into the steering column, I'm glad this pic is here...

quote Originally posted by trailboss: Does anyone have the part number for that switch? I went to my local GM dealer, told them what I wanted, and they sold me part number GM 1997988 it doesn't even remotely look like the one in the pic. I have never been into the steering column, I'm glad this pic is here...

AC Delco part number is #D6372A
Don

Controlled Cycle Windshield Wipers
The 85-88 Fiero controlled cycle (delay) wiper system has been called an error prone bugger. Seemingly random "phantom" or "ghost" wiper operations are common. Other frequent problems are: wiper operations when the turn signal is used or when the engine is first started and; wipers continuing to operate for a few swipes after being switched off.

The system has three main components; a rotary combination switch mounted in the steering column, a wiper motor and a circuit board located in the wiper motor housing.
Wiper Switch


Wiper Motor


Circuit Board




The easiest way to determine which component is faulty is by substitution. Just substitute a known good unit for the suspected bad one and see if the problem goes away. But, this isn't always possible or practical. The wiper circuits are not complicated and faults can be found by using an inexpensive multimeter and standard troubleshooting techniques.


All wiper motor circuits depend upon a mechanical connection through one motor mounting bolt for electrial ground return. A poor connection there or a malfunction in any of the three assemblies or interconnecting wiring can cause mysterious wiper behavior.

A diagram of the wiper circuit shows how the parts are interconnected. The control board is centrally located in the circuit and is easily accessible in the front compartment. Just remove the plastic wiper motor cover plate to reveal the back side of the circuit board. Voltage and resistance measurements made on the identified circuit board terminals can be used to zero in on the faulty area.

The harness connector can be removed from the motor assembly to permit measurement of the switch and washer pump circuits. The wiper switch connector can also be unplugged to make measurements. The switch connector is located near the bottom of the steering column and it looks like this.

The switch is the most difficult wiper component to replace. Steering wheel disassembly is required as described here.

The wiper circuit board (P/N 22039316) design changed many times during the ten years it was produced but all are interchangeable as shown on this chart. Here's a diagram of the assembly found on a 1988 Fiero.


Problems with this board are usually caused by aging or faulty components. The electrolytic capacitors used in the simple RC timing circuits can gradually lose the ability to store an electrical charge. The effect of this is to shorten the delay cycle interval and/or make the circuit vulnerable to false triggering. Replacement capacitors are availabe in a low cost rebuild kit from Rodney Dickman.


The large diodes can also age and exhibit an increase in reverse current conduction. In the circuit mentioned above, diode CR1 conducted in the reverse direction, slowly charging capacitor C2 until the timing circuit triggered. This "ghost wipe was really an extremely long time delay which increased in frequency as the diode aged.

A pack of four similar diodes rated at 6 Amps and 50 Peak Inverse Volts (PIV) is sold by Radio Shack as P/N 276-1661. Be sure to check replacement diode reverse conduction. In the 4-pack I purchased two were O.K. (very high reverse resistance), one was about the same as the one being replaced and one was far worse. All those diodes would likely function fine in a different application but only two of the four were good enough for the Fiero wiper board circuit.

The wiper board also has a "fuse" that can fail. It's more like a fusible link, a narrow trace on the PC board designed to melt before other components are harmed in a failure mode. The trace (shown circled here) is in the motor "brake" circuit. The circuit normally shunts the low speed motor winding when the wiper is turned or cycled off. This helps slow the motor down and stop when the "park" contacts open.

The fusible PC trace will melt if the high speed motor winding is powered on while the low speed winding is powered off. This is not supposed to happen but it can if there is a fault in the wiper switch, wiring or delay board.

If the high speed winding is powered while the low speed winding is not, the motor will act as a generator producing current in the low speed winding. Since the low speed winding is shorted when not energized, the current produced must be converted to heat. The fusible trace melts in this case, releasing the "brake" and allowing the motor to operate without restriction.

The PC trace can be repaired after the fault that caused it to melt is cleared. It's important to use very fine wire (#30 gauge?) for the repair to retain circuit protection.

see:
http://members.cox.net/2dry4u/links/wipers.html

my-fiero Great post....A+ for you.....

Thank you for your advice guys.
+'s given!

I had already eliminated the circuit board as the culprit, by getting Rodney's kit and soldering in new diodes and capacitors, so now it's time to tear the steering column apart...


I should have known something was up when the Chevy parts guy charged me only $52.00 for a switch that everyone here has paid upwards of $100.00 for the same thing. I'm just glad that I didn't have my column apart when I found out he sold me the wrong part.


I'm wondering if these guys are reputable?
They have the part for $44.00

http://www.oehq.com/

[This message has been edited by trailboss (edited 07-28-2006).]

From: http://www.fierosails.com/PartsManual.html

The wiper motors from these cars & trucks will interchange with '85-88: with pulse wiper.

Buick Skyhawk '84-89 with pulse wiper
Cadillac Cimarron '84-88
Blazer S10/GM Jimmy S15 '85-93 with pulse wiper
Blazer S10/GM Jimmy S15 '94
Chevy Cavalier '84-94 with pulse wiper
GM Syclone '91
GM Typhoon '92-93
Olds Bravada '91-94
Olds Firenza '84-88 with pulse wiper
Pontiac 2000 '84 with pulse wiper
Pontiac Astro '85-89 with pulse wiper
Pontiac Astro '90-93
Pontiac Safari (GMC) '85-89 with pulse wiper
Pontiac Safari (GMC) '90-93
Pontiac Sunbird '85-94 with pulse wiper
S10/S15/GM Sonoma '85-93 with pulse wiper


I think I would go to the local pic & pull type yard and gather up a handful of boards. And try different circuit boards.

I have seen the GM delay module in the "Help!" section.
it apparantly is a pretty widespread problem, and I heard S10 people grumbling about this is 4x4 Forums
I myself did the Rodney kit to fix the delay baord, replced the motor to fix the squirty problem, and still probably should replce my stalk, because it wipes sometimes when I hit my turn signal.

quote Originally posted by ka4nkf: I really don't understand what you mean. What I say is the wiper motor board gets 12 volts when the ignition is turned on. This is why the pulse board is giving the swipe when first turn of the ignition. If the wiper did not get any power until you turned the stalk on for wipers, then you would not have a phantom swipe. The stalk would be the switch instead of the stalk making contact with 12 volts through the wiper switch. Anyway I am not very good at explaining, but I know what I am trying to say Thanks Don

I think what you're trying to say is that it would be better if the motor never had 12v applied to it unless the switch on the column is activated. But it needs to have 12v to it to continue the sweep after you turn the stalk switch off. I may have misunderstood too. But that's why the board and motor have to be live at all times so that the wiper blades always return to the rest position no matter what position the stalk switch is in.

If anybody tries to buy a new motor be careful; none of the new motors I found available came with the wiper board