I am working on trying to find "noise" in my electrical system created by the alternator. I have no radio in the car. Can someone explain other ways an average DIY person can check/test to find this. I have a few electronic tools, but not alot.

 

I'm game to try and think of some ways to track down the noise, but I'm curious; if you don't have a radio in the car how is the noise manifesting itself? Is it affecting the operation of the computer?

A regular voltmeter won't really indicate if noise is present, an oscilloscope would probably be the best tool, but they're not kicking around in many garages.

If you have a speaker and a capacitor to connect in series with it you could build a simple monitoring device that would let you connect across the 12V of your electrical system and listen to any noise or irregular AC currents in it while you made changes.

An old 6X9 car speaker and a capacitor of about 470 microfarads (give or take) would do the trick. The capacitor blocks the flow of DC but would let audible frequencies pass through to the speaker. You can get a capacitor like this at Radio Shack or an electronics supply store - make sure to observe the polarity of the capacitor in the circuit. One lead will be marked with a black line (negative) or a series of '+' symbols, ensure that you take that side of the cap to ground or through the speaker to the +12V.

 

From reading my repair books, and following a problem for months, all thats really left is a bad alternator putting out "noise" or a false signal into the wiring system causing other sensors to mis-function. I'm getting tired of swapping/installing new parts. Esp at the cost of 100+ bux for an alternator.

I like this speaker and capacitor idea. I will have to give that a try. Gotta find old speaker first, but that shouldnt be to hard. Thanks!

 

Thats a good idea Rustydawg! I hadn't thought of doing that...but I do have access to O-scopes

How are you noticing this noise man? If you audibly hear the alternator making a noise, it means the bearings are going out. Starts to sounds like a supercharger.