I'm looking for a good introductory book on the why's and how's of working on a car's electrical system. Hopefully something a beginner like myself can use to learn about troubleshooting etc for electrical challenges. I was thinking about one titled "Fundamental Electrical Trouble shooting." Any other recommendations or thoughts would be appreciated

It's not a book, but I can highly recommend a youtube channel called ScannerDanner. The lessons are GREAT! He has a paid video course which I hear is fantastic, but the free videos are a great start for most shade tree mechanics. The course is more for actual technicians who make their living based on what they learn. Combine those lessons with a 2-year subscription to alldata.com for your car. The corporate accounts are like $200 a month, but you can get a 2-year subscription for a single vehicle model for just $30. You might also try identifix.com. It includes interactive color wiring diagrams; specifications for all the torque measurements, fluids, etcetera; part numbers; component locations; repair and replace procedures; and real world repair solutions to various problems. There is other stuff too, but that's what I can think of off the top of my head. You can print to pdf files as well. Sadly, you lose the interactive aspect of the color wiring diagrams and repair sheets when you download, but they are still the best wiring diagrams you will ever find.

A $5 test light & these wiring diagrams will help you solve 90% of all electrical problems. Add in a decent DMM and some jumper wires, and you've got the rest. There are other cool things that might save you some time/money in certain situations like a DC ammeter and inline resetting circuit breaker for finding shorts, a NOID light for injector pulse, a scan tool for DTC and other code checking...if you're really spiffy you can get one of those scan tools like a Snap-On Verus which lets you do all sorts of cool stuff like activating relays or components remotely with your little tablet. There are even probes that give you access to oscilloscope functions for compression, injector pulse, spark, sensor signals, etcetera. The only problem with the Verus and similar tools is that the cheapest you'll find one for is about $800. But it is REALLY cool! Seriously though, a test light will do like 90% of what you need.

My suggestion is a test light (maybe one with a switch to go back and forth from hot to ground quickly for added convenience, but those are like $40 - $50 instead of $5), a decent DMM that can at least measure DC 10A, diodes, and Hz like a Klein MM600 (you really don't need RMS unless you're doing AC circuits), and an old school analog induction ammeter for helping you locate shorts (You hold it next to the wire or wire bundle, and the needle deflects in the direction you need to look. Left or right. Upstream or downstream. It works because shorts draw more current, so the needle will deflect in that direction).

With the test light, DMM, and ammeter you can easily check all the common electrical problems in a car. Open circuits (a break in a wire), Short to ground circuits (an exposed/broken wire that is touching a ground), short to hot (an exposed/broken wire that is touching a voltage source), parasitic draw, sensor signals, injector pulse, spark pulse, fuses, presence and quality of voltage, presence and quality of ground, resistance, diodes, and Hz/Duty Cycle. That's about all there is for electrical testing...they are all easy to learn how to do. The rest is just sitting down with a good diagram; learning how to best narrow down your choices; and finally actually getting to where you need to go sometimes can be tricky. It's not always easy, but you get creative. Heat, vibration, and sharp edges are the enemies of wires. Look for places with those things present first, and it's usually hard to go wrong.

I really hope that this helps. I'm not sure what kind of vehicle you have, but if it happens to be a W124 Mercedes I've got the wiring diagrams. I'd be happy to share. PM me if you need them.

I'd like to update my last post with a few bits of information/corrections.

1. Apparently scannerdanner actually does have a book as well that seems to be very well organized to cover all of the different types of testing procedures. It appears to delve deeply into the fundamentals and theory as well as showing you the actual real world application of that theory. That's probably exactly the kind of thing you're looking for. It will give you a full education in the material as opposed to just teaching you how to do a few things, and that is very valuable. I think it sells for like $50 which isn't too bad... It's a bit pricey in the age of getting everything for free online, but I think it's probably worth it. There is also the video lecture series available which kind of augments everything covered in the book. I believe he teaches at a technical college in PA.

2. If you don't yet have a DMM, then I might suggest trying to find a good deal on a DC clamp meter. That way you're getting both an ammeter and DMM in one instead of having to buy, and use, 2 separate tools. The good DMM's can usually measure 10A DC, some can even measure 20A DC, but that isn't a lot of current. Also, those limits are usually only for a few seconds, and need to be followed by a 10 minute or longer period of rest to cool down if you're close to the limits of the current. 10A often won't even be enough to measure the current draw in the power distribution lines out of the fuse box. Something as simple as checking for parasitic draw could blow the fuse in your meter, and you can absolutely forget about measuring the current to the starter. Ideally, if want to have something that could measure up to say 400A. That should be enough to measure most starter circuits. If it's not, then there is a good chance there is something wrong with the circuit you're testing. It should average about 300-400A in most vehicles.

3. If money were no issue, then my ideal equipment would include what I'd describe as a super test light on steroids the Power Probe IV. Look it up... It's got all kinds of nice functions; A good DC clamp meter capable of at least 400A DC; a bi-directional scan tool like the autel or Snap-On if you're working on 96 and newer vehicles (if you get something like that, then you might want to get probes that connect to it instead of independent DMM's and clamps. They have oscilloscope features when used with the scan tool); and there is a really cool tool that ScannerDanner introduced me to called the...uactivate assistant... Something like that. It basically let's you plug it in to a relay socket, and you can test both load and control sides of the circuit. It even has a loop to hook up a clamp meter along with 4 sockets to connect your DMM probes. The problem is that it is $200, and I think that is absurd for what is basically a case, switch, connectors, and a pair of LED's. You could, however, easily make your own dirt cheap, and I think you could even make a better version. This version only tests 4pin relays. What about 5pin or more relays? How about that 9-PIN OVP relay? You could absolutely add that functionality in your own creation without too much difficulty. You could add in an extra wire that runs between the battery + terminal and another switch on the device that would let you simulate turning on the key for example. Some relays have that additional switched 12V+ pin, and it really would be easy to add. I'd bet that you could buy all the parts, including a nice weather resistant project case, for under $20, and build it in under an hour with so the head scratching and soldering time included. Heck, you could rig something together for about $5-$10 I bet in about 5-10 minutes if you wanted to. You could probably even add in relay testing capabilities as well (this device currently tests the circuit, not the relay itself).

TLDR- SCANNERDANNER does offer a pretty good book apparently in both digital and hard copy. I really like the Power Probe IV. A good DC clamp meter can kill 2 birds with 1 stone. And you can build your own version of the $200 "uActivate" relay circuit tester both cheaply and easily.

You might be able to get a used copy of the scannerdanner or other books on eBay and sometimes Amazon.

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84 300D, 82 Volvo 244Gl Diesel