Electrical test equipment needed....
 

Hi guys,
My alternator light blinked a couple of times today while at idle. I'm thinking that Voltage Regulator is going out similar to this guy's problem (with the exception of the flickers at startup, just while idling at lights).

http://forums.pelicanparts.com/showt...ght+alternator

Anyhow I wanted to perform the same tests he did at the battery, but I only have the following Sears cheapo multimeter. http://www.sears.com/sr/javasr/produ...id=03482141000

I'm assuming that connecting this directly to car battery will blow it since it's only rated for 10 Amps. Am I correct? Does anyone have a meter I can test with?

Further considerations: I replaced spark plugs, cap and rotor, but I don't see how that would cause my alt light to come on. Thanks for your help!

Steve,

I'm not entirely sure what you are checking out, so sorry if I'm off target here - but if it's voltage...

First, most DVOM's (even the ones for $19.99) are internally fused, so don't worry too much about it. You won't blow the meter maybe just a fuse within it, and then usually only if you have a direct short somewhere or set the range of the meter too low for the volts you are working with.

If you are checking ampre draw (how much current is passing through a point) -which the pelican thread wasn't doing - then you really need a amprobe clamp meter (I have one you're welcome to use).

But if you are checking voltage not amps from point to point, then the DVOM meter you have works fine. Make sure the meter's voltage range you select goes higher than 15 volts when working with the alternator.

In order to test voltage at different points in the circuit, put the (negative) black lead on an earth ground, like the (-) post of the battery or another clean metal point such as the deck lid hinge. Then touch the red lead to the wire or connector you want to check the voltage.

The meter itself has a very high impedance, and doesn't draw current by itself, this makes it possible to check beteen the two posts of a battery without causing a short or high current draw. You do NOT want to put the meter 'in-line' with a battery wire, or you will subject the meter and it's measly 16 ga. wires to the same current as the much larger battery cables - sure to cause a major problem. Testing from point 'a' to ground, or point 'b' to ground will allow you to test the voltage on about anything (even the 200amp main in your house - though best left to your electrician)

Keep in mind however that on some newer cars like the 996, the small voltage generated by the battery in some meters fed in the wrong direction could blow the delicate electronics of some modern CMOS chips in cars. So beware as the meter can be used in some - but not all places on some of these cars.

Hope that helps, and please someone correct me on any errors....etc

Keith

Check the fan belt first to make sure it isn't worn or slipping as that could be the source of your problems.

I have all needed equpment to fully test alt, bat and system.bat tester with load, DC amp meter and mutlimeter. Doug is dead on start with the simple and work up from there.

It is old and on the list of things to do. Maybe it has glazed a bit... Much like the other parts of the car, it has not seen a lot of driving in the past few years. I'll eventually get them all done and then start at the beginning again. :roll:

Did I test this correctly??
 

Ok, I used my little Sears meter and tested at the battery - thanks Keith.
The meter read 12.xx with the engine off. With the engine running at idle, it was around 13.5V and at 3000 rpm it was 14.1 V. So I'm guessing that all is good, since I got results different than the guy in the posted thread right?

BTW: how do you remove the A/C belt? Do I just take off the nut in the center of the compressor and remove the pulley?

Results look good to me.


The AC belt comes off by sliding the base of the compressor, dont loosen the center of the compressor. This is from memory, the adjuster nut is next to the fan, loosen that. There are then 2 13's in the front and 2 in the back that hold down the compressor. I cant remember what mounting points are slotted which let the compressor slide, pretty straight forward once you are looking at it.

Cool. Many thanks!