Bruce Amacker Posted February 22, 2009 Share Posted February 22, 2009 My Level 1 Electrical Troubleshooting class is 16 hours and covers: DVOM use (volts, Ohms and amps), voltage drops, proper testing of starters and alternators, circuit protection, relay use and relay circuit testing. It does not cover any computer circuits, sensors, or driveability issues. It barely touches on Schematic Interpretation, which is a Level 2 16 hour class. It is a very "hands-on" class with each student getting a demonstrator board and completing numerous tests in the classroom with a DVOM. After a strong background in the basics, the class goes into the shop to perform live testing on a car and MD truck. Tests include: alt voltage drop, starter voltage drop, battery testing, alternator testing, starter amperage testing, key off parasitic drain, and the completion of a 10 minute electrical check sheet. We've taught this class numerous times and find that on the average: 10-20% of the students excel at all areas before the class starts. 50% gain a large amount of knowledge during the class 25% learn only a little and probably never will become proficient at electrical theory. (some guys will never "get it".) It's surprising how many techs think a relay is a circuit protection device, and at least 3/4 of techs do not know how to diagnose a relay circuit. (Using a test light to look for power, load, ground, and trigger) Anthony does 90% of our classes, but I'll be doing this class and a 16 hour 6.0 PSD class in Salem, Oregon in a couple of weeks. They are for the Oregon Fire Mechanics Association and some of the few classes we do that are open to the public. Damon and I wrote this diag sheet several years ago, it's what we use in class. If anyone wants it is a MS Word format, let me know. I also use a car version of it in class (single battery). WORK ORDER STARTING & CHARGING and BASIC ELECTRICAL Worksheet , IH 4000 Series TEST BATTERY STATE OF CHARGE: Perform visual check- loose posts, bulging cases, leaks, etc. Check electrolyte level and gravity if possible. Start engine, record volts at high engine idle TIP: Voltage should be 13.6 or higher here; if low, amps measured should be high. RESULTS ______________ Volts [OK / FAILED below 13.6V] Measure alternator amperage output: wait for amperage to stabilize low (below 15 amps if possible) TIP: If amps do not come down after 5 minutes of high idle speed, charge batteries with charger or replace, if authorized and stop further testing. DO NOT LOAD BATTERIES DURING THIS PORTION OF TEST! (Checking charge rate excludes shorted batteries) RESULTS __________Volts @ ___________Amps (no load) [OK / FAILED above 15A] BATTERY OPEN CIRCUIT VOLTAGE CHECK Remove at least one battery cable to isolate the batteries and record battery voltage with engine OFF. TIP: Voltage should be 12.5 Volts or higher at this point. If voltage is 12.45 or less, and the truck has been out of service, charge batteries. If voltage is less than 12.4 and the truck has been in service (with good alternator), remove battery cables and test voltage independently. Good batteries and a good alternator will NOT be under 12.5v. If over 12.8, remove surface charge with headlights and blower motor for 5 minutes. Battery 1 Measurement:______________________V Battery 2 Measurement:______________________V BATTERY LOAD TEST Remove cables from battery(ies) to isolate. Perform carbon pile load test at ½ rated CCA for 15 seconds on each battery. Alternate method: load to 9.6v for 15 seconds and record amperage. Use this method and double this number to determine CCA capacity of battery if no label is present. Battery 1 _______ Volts @ ___________ Amps (15 seconds) [OK / FAILED] Battery 2 _______ Volts @ ___________ Amps (15 seconds) [OK / FAILED] Continue: Volts should recover to 12.6 after 5 minutes rest. [YES / NO] TEST ALTERNATOR Step 1: Visual check of belt tension and integrity of alternator mount (not loose). Load Test: Using carbon pile, load battery to 12.0 Volts with engine at 2000rpm; record amperage output of alternator TIP: Amps output should be alternator rated output +/- 10% …keep amps pickup at least 6” away from alternator case, due to magnetic interference. RESULTS Max Amps output ____________Amps. [OK / FAILED] AC DIODE TEST Check AC voltage (at alternator if possible; if not, check at battery) using DVOM set on AC voltage and record. Most will read between .02VAC and .05VAC RESULTS ________________Volts AC. [OK / FAILED at .2vac] Test alternator voltage drop: With engine running, measure voltage between alternator hot stud and positive battery post, with a DVOM set on DC Volts. (.4v max) Measurement:______________________________ With engine running, measure voltage between alternator case (ground) and negative battery post with a DVOM set on DC Volts (.3v max) Measurement:______________________________ TEST STARTER DRAW: Disable cam sensor and measure amp draw of starter: 500 amp surge OK, should stabilize at 350-400 amps for 10 seconds. Measurement :___________________________________amps TEST VOLTAGE DROPS: Test starter voltage drops: Measure voltage from starter positive stud to battery positive stud while cranking, with a DVOM set on DC Volts. Voltage should be under .5v Measurement:_______________________________ Measure voltage from starter ground stud (or starter case) to battery negative post while cranking, with a DVOM set on DC Volts. Voltage should be under .5v Measurement:_______________________________ Cab Power Feed Voltage Drop Test: The cab 12v hot power stud is located behind the fuse box in the dashboard, with several eyelets mounted to it. Measure voltage level between this stud and the battery positive post with cab heater and all lights on, with a DVOM set on DC Volts. Voltage should read less than .2v. Measurement______________________________________________ Cab Ground Voltage Drop Test: Measure voltage between the battery ground stud and a metal dashboard screw on the lower left of the dashboard with a DVOM set on DC Volts. All accessories and lights should be on. Voltage should read less than .4v. Measurement______________________________________________ Quote Link to comment Share on other sites More sharing options...
Shlep Posted February 22, 2009 Share Posted February 22, 2009 I'd be interested in what ever you have available Bruce, as I've got about 5 guys that need a "basic" refresher on your various DVOM functions, as well as voltage drops across circuits. And for some strange reason it's become my job to teach them. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted February 23, 2009 Share Posted February 23, 2009 I'd be interested in what ever you have available Bruce, as I've got about 5 guys that need a "basic" refresher on your various DVOM functions, as well as voltage drops across circuits. And for some strange reason it's become my job to teach them. You could use my books as a format for teaching them the proper ways of doing diagnostics. They are full color, 289 pages, with a picture on every page and usually a short paragraph explaining the graphic. Very clear, detailed, easy to understand descriptions of procedures are included for all of the common electrical tests. They are formatted for a 16 hour class, but in your situation, I'd suggest doing a few pages each day, at break or at lunch, as the info will absorb in better that way. They will always have the book for quick reference a long time from now when they can't quite remember how...... Here's a couple of pages from the book so you'd have an idea of what you're getting: We add an electromagnet to pull the switch closed- our “Remote Control.” Hooking power to D and grounding pin E would create a magnetic force, pulling the switch shut, just as if you threw it yourself. This is called the Control Side. Adapters: PN CT6100 from Matco or Snap-On, $15 You’d think it would be easy to insert a male spade into the fuse terminals, but it isn‘t so. Don’t forget how important it is not to damage the fuse terminal connectors by spreading them out. If you spread out a fuse terminal you will build a ghost into the vehicle like you’ve never seen before! Voltage drop on a starter positive is measured from the battery positive post to the starter hot stud. It must be measured with the starter cranking! To disable the engine from starting, unplug the crank sensor, disable the injectors, or coil packs. Website price on this book is $79.95. If you buy a few I'll sell them for $60. I promise you won't be disappointed in the book. (Sorry for the blatant ad, Keith!) Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 23, 2009 Share Posted February 23, 2009 (Sorry for the blatant ad, Keith!) Don't apologize! This forum is about sharing information and learning right? Beyond that, you have been a supporter of the DTS since the beginning and our longest advertiser - sell your trinkets, talkies and leaflets as needed. Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted February 27, 2009 Share Posted February 27, 2009 I guarantee you will NOT be dissapointed in Bruces books. I have both the 7.3&6.0 books and they are awesome! They are very well written, easy to understand, and written for the technician. I would reccomend these books to anybody. I am sure that anyone who gets them will not be disappointed. They have paid for themselves several times already. Quote Link to comment Share on other sites More sharing options...
Shlep Posted February 27, 2009 Share Posted February 27, 2009 Yeah I'm trying to get it past the bean counters but so far no go, if not I'll have to pick them up for personal reference. Quote Link to comment Share on other sites More sharing options...
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