Hello All. I do not know anything about automotive electronics. Nada. In fact, I struggle to grasp the entire concept of electricity (I'm a if you can't see or touch, it doesn't exist kind of guy ... lol). I am looking for two recommendations.

The first is for a really good book that explains the basics and is diagnostically oriented to troubleshoot automotive issues i.e. how to measure things and troubleshoot things when there is an electrical problem. I do not need to have it written for an engineer or technologist .... nor do I care about things such as in-depth circuit design, electronic systems architecture etc. Way above my head and interests.

The second recommendation I'm looking for is for a good automotive multimeter. I want a meter I can use to diagnose basic things/problems such as current, ohms etc. I don't want to spend a fortune on a Fluke-like brand etc. but it should be fairly robust.

Your recommendations and comments are appreciated. Thanks in advance.

 

I don't know of a book lately that you could use, though there are probably some out there. There is a lot of stuff online for free though. I did a search and this came up, it looks pretty good.
https://www.ericthecarguy.com/faq/so...iveElectricity

If you have questions about anything, just post in here and we will help you through it.

I have found many different cheaper meters that do ok for automotive work. I will warn you, a digital meter is fine and is required to work on fuel injected/electronic parts of a vehicle, but they do not work well sometimes for troubleshooting the regular lighting and normal circuits. The digital meter presents a very light load when testing circuits, which can be a problem when you have a circuit with high resistance and corrosion that is causing a problem. The digital meter will not pick this up unless the load for the circuit is kept in place. A testlight should be part of your troubleshooting arsenal.

 

Here's a decent meter for a decent price with good reviews.
Innova Auto-Ranging digital multimeter 3320 - Read Reviews on Innova #3320

You can get it cheaper on Amazon.

 

Thanks for your posts and links Dave. I know the FTE crowd is great about helping to diagnose things. The problem for me is when someone says "take your tester and measure the voltage output on the xx" ... I'm lost already. What tester? Test where? What am I looking for?

You get the picture. That's why I need to get up to speed on automotive electronic basics. I really want to understand what it is I'm doing and I do not want to waste anyone's time here.

I also found the Innova 3320 multimeter while researching and reading dozens of reviews. I think I'll go ahead and order one. I also found the INNOVA 3420 Smart Test Light / Circuit Tester. Your thoughts on this one?

https://www.amazon.com/INNOVA-3420-S...Circuit+Tester

Another multimeter I found is this one. What do you think?

https://www.amazon.ca/dp/B00NWGZ4XC/...=IPMSISQQK4RF1


Reps sent.

 

I don't like that testlight. It has batteries and LED's, that tells me is has circuitry in it and may also present not much load on the circuit. I like the ones that are just a simple incandescent bulb inside, no batteries. A good place to get one is Harbor Freight, I am sure you could find one online also.

Your second meter you picked has that large current clamp on it. That is ok if you need to measure current in your house circuits, it's A/C only. It will not work on anything on a car. You can buy them that measure DC current, but they are way more expensive. The first meter will read DC current if you move the leads around, I think it's rated for 10 amps.

Do you understand plumbing(water pressure, water flow, pipe size, pumps, etc?). If you do, that can be a help, I can describe what is going on with electricity with analogies in plumbing.

 

OK thanks. I thought with the "ground" detect feature and 12v socket plug ... more meant better. How about this test light? It gets good reviews and is a HD basic unit. BTW - we don't have HF up here in the Great White North .... we do have Princess Auto ... similar kind of store.

https://www.amazon.ca/dp/B000M5ZWBA/...I2GHIW34L9YXBS

I do understand plumbing and do most of my own plumbing work. I've heard people say electricity and plumbing are similar. Again, I guess I'm a visual learner ... I know when a sweat joint is bad (it leaks and it's wet). When you have a "parasitic electricity drain" ... to me that means the invisible boogey man is out there somewhere but you can't see him.

 

That's the type of circuit tester that works well, all it has is a bulb in it.

If you want to think of the battery as a source of water, then the voltage would be the same as water pressure, the current would be the same as water flow.

More flow in the water system means you need a bigger pipe to carry it through. The same with electricity, more current flow means you need a larger wire to carry it. The starter needs a lot of flow to get the power it needs to turn the engine over, so that is why it has that very large wire going to it. Light bulbs and other small circuits don't need as much flow to work, so they have smaller wires going to them.

Here is a pretty neat formula that is easy to remember; P=I x E. P is power in watts, I is current flow in amps, E is voltage in volts.

Let's say there is 150 amps flowing through the large wire from the battery to the starter when the engine is cranking. If we have 12v at the starter, then the starter is using 150 x 12 = 1800 watts of power to turn the engine over.

If we installed a 120v starter on our car, then if it still uses 1800w of power to turn the engine over, then 1800 divided by 120 = 15 amps. It would only take 15 amps to start the engine, so instead of that very large fat wire, you would only need a 14 gauge wire (smaller pipe) since the current flow is so much lower.

This is exactly what the power company does, and why they run thousands of volts on those large cross country power lines. They run the voltage really high, so the current is lower. They can then run smaller wires on the towers, but are still transferring the same amount of power. When they get to where they want to be, they use a transformer to bring the voltage down so you can use it in your house.

 

OK ... I get this. Thx.