What do I need to look for when getting a digital multimeter?

I was looking at some Craftsman and Fluke multimeters in Sears. They have a 7, 8, 10, and 11 function multimeter. The last time I used a multimeter, it had the option for 4, 6, or 8cyl engines. None of these had that option. It's been a long while since I have used one, and honestly, I don't know which one I need for my Buick. Any suggestions?

 

If you're looking for something that will show ignition dwell and RPM, a digital "multimeter" is not going to fit the bill. You want something along the lines of what's called a Dwell/Tach/Voltmeter. A "multimeter" is used for general electrical measurements and won't do anything for rpm or dwell.

http://www.google.com/search?source...gc.r_pw.&fp=5dbaa129002be11e&biw=1411&bih=695

Devon

 

I still use a cheapy one from Radio Shack that I got ten years ago. It runs off two small watch batteries and is about 4 inches long by 1.5 inches wide and 3/4" tall. It's digital and auto-ranges. A couple years ago I picked up a fancier one with fancy leads and such, and I haven't even openned the package it's in.

I use the Continuity tester, Voltage tester, Ohm Tester and because the EFI I've used the Diode tester.

 

Most any meter nowadays will do for basic circuit testing. You don't have to spend more than $30 or $40 on one.
30+ years ago I bought my Fluke - I still have it. I paid about $150.00 for it. Today you can buy a Sperry(?) for about $40.00 at home depot that has almost all the same features.

 

I didn't realize there were two different meters. Makes sense now.

Currently, I have something killing my battery and need to determine if it's the voltage regulator or the alternator. I cannot remember which posts to jump on the voltage regulator to test this, so I figured I would play it safe and get a cheap meter and do it the correct way. Thanks for all of the information.

 

There is a real easy test to check the alternator (external regulator) but you have to be very careful...

Disconnect the small plug at the back of the alternator. This is the plug to the brush assembly. Find the "F" or field terminal on the alternator.

Put your test leads from your voltmeter on the battery to measure the battery voltage. You should read about 12v. Leave them connected.

Connect another lead from the positive side of the battery. Use another test lead if you have one. You can use any wire, but you need a small pin connector at the end for the next step. (Keep the free end from touching anything!)

Start the car.

Touch the free end of the test lead connected to the plus side of the battery to the F terminal on the alternator. This will apply a full 12 v to the field coil. On the voltmeter, you should see the voltage on the battery immediately start going up as the alternator starts to charge the battery. This is the careful part as it it not easy to do, especially if you have AC....

As soon as you see the voltage going up, remove the lead from the F terminal. You can do it again to verify, but don't keep the lead on too long as the voltage will keep going up. Try not to touch anything else.

This will tell you if the alternator is working.

Also, with the engine off, you can touch the same test lead to the R terminal on the plug to the regulator and hear the ignition coil in the regulator click. This will tell you if thats working. Don't try this if the regulator is solid state....

Reconnect the plug to the alternator and you are done.

- Bill

 

Thanks for this info. I do have A/C, and the alternator is a bit tricky to get to as you have described. How do I know if my Volotage Regulator is solid state or not?

 

"Typically" if the voltage regulator is 2 plus inches tall it's an old style one, if it's an inch or so tall it's a solid state. That's from general observation, there 'could' be exceptions to that.

 

Yup - you can take the cover off too and see if there are copper coils inside - they look like relays. That would be mechanical.

- Bill

 

I'll update with some pictures of the VR for verification before I do anything. Thanks again for the info.

 

Forgot to get a picture of the VR, but the problem has been solved. Turns out it was the battery not holding a charge. I took the battery back to the place that I originally purchased it at 6.5 years ago (Oreilly Auto). They looked up the warranty info on the computer and told me that they were just going to replace it since it only had a couple months left on the 7yr warranty. Can't beat a free battery.

With the new battery in, the first thing I noticed was how fast the engine cranks when starting it. I cannot remember it spinning over that fast with the old battery. Same cranking amps on both batteries. I drove it around for a while, shut it off, restarted it, and drove some more. Everything seems good so far and the battery gauge does show that it is on the charging side (though I cannot confirm if the gauge works or not, but it does move).

Now to get that dwell, tach, volt meter so I can be sure that it was only the battery before I do anymore driving. Oh, and also the picture of the VR.

 

I think that this would be a very reasonable investment and do the job quite nicely for you. From Sears.

http://www.sears.com/shc/s/p_10153_12605_00920925000P?prdNo=1&blockNo=1&blockType=G1

 

i have a fluke 77 series one that works great in good cosmetis condition with owners manual, fluke rubber shroud w/built in stand, (green/gray)fluke soft case, and fluke leads plus an extra set of cheapie accessory leads(with their own varios adapters).
50 bux gets is shipped to you. it has never let me down. owned it 15 years,bought it used.
i recently bought a new fluke that does more stuff.

if you dont jump on it by friday eve. first come first served (lower 48)after that.

 

here is a pic of it all.