By Elvis L. Hoffpauir, MACS president and COO
The member request started out like this: “I need help or if you can send me the right contact. I need the diagram of the electric system…”
That question (and we get a lot of them just like that) made me think of an article Paul Weissler, senior technical writer for MACS, wrote for this journal back in 2014, “Service information: Where to get it and how to use it.” Given this issue’s theme, “A/C diagnostics and trouble-shooting,” the following excerpts from Paul’s article bear repeating here.
“Some of the jobs that come into the shop often don’t seem to even need diagnoses, and in fact they may not. After all, if a belt snaps at high mileage and shows normal cracking and chunking, you’ll just replace it. Ditto for an 8-year-old car that’s lost about 50% of its refrigerant charge and is performing poorly as a result. Or you can see rock damage to the underside of a condenser that’s leaking as a result. If your workdays were filled with jobs like that, you probably wouldn’t even need much in the way of diagnostic help.”
“But more realistically, even the obvious problems have root causes you have to diagnose, to avoid a comeback. And just as important, you normally need help with doing the job itself, both with the R&R (remove and reinstall/replace) sequence and where parts and connections are located. That means you need an extensive service information system.”
“If a shop services a range of vehicles, an internet connection and one or more of the online information sources will be necessary. Each of the online services offers some features the others do not, or not to the same extent.”
“Even when the problem is obvious, good practice still is to first check service bulletins, a step that by the way will identify any major specification change. Sure, most of the bulletins are for factory fixes, but they often cover root causes, and not always on the latest model cars”
“The major aftermarket information systems (Mitchell Prodemand, AllData and Identifix Direct Hit) are up-to-date sources for all bulletins, and that means they’re posted right after they appear on factory websites. But they actually may be more convenient to use, because they typically list all the bulletins in a specific category for a period of several years, while the OE bulletins are often referenced to a specific model/year listings.”
”We’ve mentioned the issue of OE information not on the aftermarket sites. So if you have trouble interpreting a diagram, you should ask your aftermarket information system if there is a circuit description on the OE site. Or you may choose to look at the OE site on a short-term subscription.”
You can go to this link for additional links to all the OE websites:
(MACS members can review Paul’s complete article by signing in to the MACS website, selecting Publications, and then Action Archives from the drop-down box. The article can be found in the Sept/Oct 2014 issue, beginning on page 16.)
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