I keep on burning out pulse boards on my 86 Fiero Coupe. They do not last more then a day or two. The boards wind up smoking and begin to melt. I purchased a Dorman pulse board (part # 906109), from Rockauto, which is the replacement part for the AC Delco board (part # 22039316). The online catalog says that they are interchangeable for the 86. The original AC Delco board that was in the car stayed on, even if the switch was off. The part # for that board is 22048550. The wiper motor part number is 20488522. Are these correct boards for the motor? Does it sound like I have a bad motor? Or is it the wrong wiper motor in the car? I took pictures of two boards and the motor. Any help would be useful.
------------------ 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)
Alrighty, well I replaced my wiper motor with a completely new motor and same result a melted pulse board. I was driving with my wipers off after I just put in the new motor and new pulse board, I began to smell melting plastic while driving. Pulled over, opened the front hood and saw my pulse board melted. Any clue whats going on? How to fix? Please Help!
Originally posted by Mykola: Alrighty, well I replaced my wiper motor with a completely new motor and same result a melted pulse board. I was driving with my wipers off after I just put in the new motor and new pulse board, I began to smell melting plastic while driving. Pulled over, opened the front hood and saw my pulse board melted. Any clue whats going on? How to fix? Please Help!
Picture of new board? or same burn at top or bottom above image? Top burn not = bottom burn. different circuits.
top not sure bottom is high speed. Not much attach to that circuit expect the switch.
The board that melted again was a Dorman. It melted just as the one on the bottom of the picture (the greener one). My next idea to do is to find the switch. Any other suggestions would be helpful. Thanks.
Obviously there is a problem and it is most likely not the PC Boards. If it were my car, I would get the schematics and remove the wiper motor and apply power to the correct terminals and make sure the motor operates correctly at all speeds. Then I would make sure there is no mechanical binding with the wiper arms and mechanisms. If that checks out, you can reinstall the motor and apply 12V and GND to the correct terminals again to make sure all is still OK. If that works, you need to find the short or open in the wiring leading to the wiper stalk. With the Key in ACCY or RUN and the connector to the wiper motor disconnected, check the voltages at the connector pins when you move the wiper position to low, high, mist, etc. For example, set the wiper switch to LOW, put the ground lead of the test light to a solid ground point and touch terminal C on the wiper connector. It should light. Then touch all the other terminals, they should not light. Repeat this for each position of the switch and every terminal on the connector. You can use a 12V test light but a digital Volt OHM Meter is better. I suspect you will find something is amiss here, either there will be no power to one of the terminals when there is supposed to be or there will be power to two terminals at once. Once you determine if the switch and wiring are good or not then you can proceed with repairs. Just to keep installing new PCB's is not going to do it.
If you use the link above you can down load the 87 service manual, the wiper schematics start on page 980.
SO mine died today too, just thought I'd add to the mayhem. The board doesn't look all that bad besides the solder joint in the bottom left of the second pic (may just be discoloration)...
It's kinda late so I didn't look for my multimeter (it's not easily accessible without moving the car), I'll probably do the testing tomorrow. They never slowed or anything, just stopped mid-stroke. For temporary I may be able to wire low/high speed but I have to double check before I burn anything up (ask me how I know).
[This message has been edited by Doober (edited 02-12-2013).]
devices burn out for one reason: too much current (amperage). I'm an electrical engineering student and have burned my fair share of components. What you need to do is get your multi-meter out and check that connections current, and see if it is too high for the specs. Or if you don't know the specs, you could check the fuses to make sure you don't have one thats too big in the wrong place. Another thing to check is make sure you don't have power from a lose wire or a bare wire/contact medium contacting the one that's burning stuff and delivering extra current to it.
The big idea here is to make sure that circuit has no extra outside input. Circuit needs to be clean (from power source to component to ground)
If that doesn't work check other circuits that might be effecting it in a round about way.
I'm not an EE student, but I know enough about electronics to +1 that
I upgraded the firewall ground in my '78 Malibu frame-off, and cleaned all the inside grounds thoroughly. The gauges used to move previously since the lighting in the cluster was finding its way through the gauges and then through the sending units, but now they're rock steady.
I have the exact same problem with my 86 GT. When i bought it the board was burn't up, i replaced and it burn't through it the same day it was replaced. All of a sudden the wipers started twitching up and down. please let me know if you find a solution, thanks.
The fuse had enough corrosion on it to keep the wipers from working. Cleaned it up and all is well.
