1985-1998 [Subscribe to Daily Digest] |
I think it helps to know something about electrical theory, but for most electrical repairs, the concepts are: using a thick enough wire to carry the current, achieving a good connection, and making sure that there is an adequate connection to ground. In almost all cars, as you probably know, the negative battery terminal is connected to the car's chassis, and this is the ground. A faulty ground can be the cause of many an electrical problem. Wiring diagrams are not that hard to decipher, if you start first with figuring out what should be positive, what should be grounded, and what wires or connections should turn off our on and in what circumstances. For example, a diagram would show that the power to the electrical central locking system is not routed through the ignition relay, but is connected straight to the battery, so that it works at all times.
Tools you need:
1. VOM (volt-ohm-milliamp meter). Use this to check the amount of voltage in your system (DC volts), and to check for a decent connection, using the ohmmeter function. A perfect connection has no resistance to current flow, aka zero ohms. So if you suspect a poor ground connection in your component, check the amount of resistance between a good, shiny chassis point and any part of the component that should be grounded. Problem 1 example: I had an intermittent windshield wiper problem that eluded diagnosis for months, until I noticed that it rocked in its mountings while it was working, and that the ground connection resistance fluctuated during this. Problem solved by running a new ground wire. I think I connected it to a spot on the engine. Problem 2: sometimes the car wouldn't start, and battery terminal corroded. Voltage between battery terminals good - about 13.5 volts (they call it a 12V battery, but it's slightly more, actually), but if I measured voltage further down the red cable from the battery, 9 volts. So the corrosion was causing a "voltage drop", and my starter wasn't getting enough voltage to kick in the solenoid. Read the instruction booklet that comes with the VOM, so you don't have to buy a second one. Your car battery produces enough current to the fry the thing, if you have it on the wrong setting.
2. multi-function wire crimp, cut, strip tool.
3. cutters for those tight spaces.
4. Soldering gun with resin core solder.
5. Pliers
6. Plastic zip ties. They make your installation look great and prevent wires from rubbing on things.
7. Consider a book about electricity, especially one that explains solenoids, relays, switches and motors. Browsing at bookstore is best option. I looked on Amazon.com, but there wasn't anything there. One book showed two cute women looking like they were working on a car's electrical system, but I suspect they were just models. :-)
Good luck.
posted by 205.213.12...
, Wed, 13 Apr 2005 12:41:08
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
