Help! My car is a 2002 Isuzu Axiom 2wd 6-cylinder. The problem is that the front wipers have stopped working in intermittent mode, and they don't return to home when I shut them off. The rear wiper works fine. Is there anybody out there than knows how to fix this? Its a perfectly good car that I will have to abandon if I can't fix this one stupid problem. Its been this way for years, yet it somehow passed inspection. But now this year, it failed the safety inspection and I can't drive it legally until its fixed. My mechanic has looked at it and can't figure out what might be wrong or where to find a relay or control switch, or whatever. I can't find any isntructions or diagrams online. My mechanic is not comfortable just tearing apart my dashboard, and that would be too expensive anyway. The wiper motor is in great condition and seems to be working fine.
Measure the voltages on all of the wires at the wiper motor's connector. One of them must have 12 volts all the time when the ignition switch is in the "run" position, even when the wipers are turned off. That is the circuit that runs the motor until it parks. I'm not sure if that is related to the dead intermittent function though but given the multiple symptoms, also test for voltage right on the wiper motor's metal housing when the switch is in delay mode. If you see a voltage there that comes and goes at the same rate as the wipers should be taking a swipe, the motor has a bad ground. The motor is usually bolted to a metal plate, and that plate is mounted on rubber bushings to isolate the vibration, but that also isolates it electrically. Look for a brass strip riveted to that plate and going under one of the bolt heads. If that ground strap is making a bad connection, don't even bother trying to fix it. Just attach a new ground wire from the motor to the car body.
November, 21, 2012 AT 12:00 AM
Thanks for the reply. Attaching a ground wire to the motor is one of the first things my mechnic did in trying to troubleshoot, so great minds think alike : ) I think we are 99% certain its not with the motor, but with a relay that controls the wiper 'delay'. After much research, I found an isuzu forum where people with a similar problem are reporting success when switching out a relay that is in a sealed circuit board behind the glove box. Luckily someone posted an online supplier who provides the aftermarket relays. The new relays have arrived and I plan to do an operation this weekend. I hope it goes well though, as it will be my first time soldering. Radio Shack, don't let me down. Haha. I will post the results here so you can know whether I was successful or not. Again, thank you.
November, 21, 2012 AT 3:31 AM
Hope that solves the problem.
Removing a soldered-in relay will not be easy because after you melt the solder on one terminal, it will harden again before you get the others melted. If you put a little sideways pressure on it, you might get one terminal at a time to lift a little. Keep working around all the pins that way but be careful to not push so hard that you crack the board. Then you have to send it to me. I've repaired a lot of cracked front circuit boards on radios that the UPS basketball team dropped on their way to me.
You can also use a small suction bulb to suck off the molten solder. I use a product called "solder wick". That's a copper braided wire with flux in it to make that molten solder flow into it and off the board. For what you're doing it's not practical to buy a whole roll of the stuff.
When you solder, heat the terminal and the copper circuit on the board at the same time, and touch the solder to the other side of the terminal. When it melts it will flow toward the heat source and coat the connection. Don't heat the connection any longer than necessary because the copper can lift off the board. It can still work that way, but that copper is also the mechanical connection that holds the relay in place. If too many of the copper circuits are lifted, vibration will eventually cause them to crack resulting in a broken circuit. I can fix that too.