Questions and Answers

Jetta Electrical Problems Q. Hi Vincent, I have a 1987 Volkswagon Jetta, no power steering, and standard. That's about all I know about it. It is having some electrical problems; I had the battery and negative side cables replaced recently. Since I've owned the car, (nine months), the tachometer will go in and out, that is to say it works about once a month.

I popped the hood to see if I could track down any wires. I pulled out the dashboard to chase the wires as well, to see if they are corroded or disconnected. My Chilton's guide doesn't show the tachometer connection, and I have no idea how it talks to the engine. Could it be something simple like a fuse or a loose wire?

If you have access to a diagram of the connections, it sure would help me out. Secondly, the battery (new) has trouble holding a charge, so I pulled out my radio, it seems to hold a charge better, but it still hates to start. Oh, and the alternator is shiny and new as well. Besides all that, there are two wires under the hood that are just dangling, and I can't find the mates to.

Where can I find an online guide of what the electrical system might look like?

Thanks for any help at all.
Mike G.

A. I think the only place you're going to find a wiring diagram online is at ALLDATA. A single vehicle subscription is only$24.95 per year and I think it's well worth it.

If you want diagrams for free, then the reference section of your local public library will have them.

If the tachometer goes on and off, it is likely a loose connection.

It sounds like there is a drain on the battery. The best way to start looking for it is to disconnect the Negative battery cable and install an ammeter in line. Note the reading and then start removing fuses one by one until you see the amps drop. That will be the circuit that has the draw. Then you can track it down from there.