Anyone know anything about amp testers, I'm trying to figure out how to test the amp draw on a starter on a machine and the book tells me I need an amp tester that is capable of at least 500 amps, the only thing that comes to mind is a carbon pile tester, never had one, maybe should have years ago, but know nothing about them. Anyone have any advice on this or something better to use??
Look for a "clamp meter". Hooks around the cable and measures current. For our industry, high accuracy isn't necessary and a cheap Chinese one will be good enough.
Don't forget you're looking for a DC amp meter. An AC only meter won't help any.
Depending on what kind of meter you have, you can probably pick up an amp clamp for it. Or you can buy an inexpensive multi meter with the amp clamp built in on the top. I have a cheaper multi meter with the built in amp clamp that I found myself using more often than my Fluke 88, simply because I would use the amp clamp to hang the meter from another harness when doing some testing. I could hang it right in front of my face when working under a truck.
Can anyone tell me where to buy one, what they should cost and maybe even what they look like with a link to a photo page, anything electrical isn't my strong suit by any means. Even a brand and model number would be a big help.
Used to have an amp meter with just a little sheet metal channel across the back of it, you just held the meter on the battery cable and engaged the starter, picked up the magnetic field from the battery cable, like an amp clamp only simpler. Worked slick.
Look on eBay, quite a selection. I also recommend Dan Sullivan's book on Fundamental Electric Troubleshooting.
Yair . . . Randy88 . My old girl looks a bit like this . . . . real handy bit of gear. I reckon these days they would be less than a hundred bucks for an adequate el cheapo.
http://www.aeswave.com/ShopBook-Fundamental-Electrical-Troubleshooting-p8752.html Dan Sullivan's book, best I have seen.
Thanks guys, just what I was looking for, the book is a major plus and will order it in the morning.
My Fluke meter 376 has two selection settings for amps: one for Ac and one for Dc. This meter came about for (1) checking Dc welding current for stick as well as flux core FCAW (some folks call it mig) as well as (2) Dc starter draw. At the time I shopped at the Harbor Freight store, their meter ended up not being able to do Dc and if I recall the dial also didnt have a Dc amp setting. This meter is sure convenient But I recall there is a method to do this w/o an inductive meter so I searched around and it is most likely a gizmo called a shunt. Here is a link to one person's use of this device: http://www.beamalarm.com/Documents/measuring_rv_battery_current_with_shunts.html and notice on the next page .... http://www.beamalarm.com/Documents/adding_shunts_to_batteries.html ....how the shunt was able to show each battery working/not working while the dual battery system was in operation....yes that is a little off topic but shows other uses for the shunt than just testing the starter. . ssa
Interesting links, thanks, O'bob
RBMcCloskey, just got the book today in the mail. best book ever is a mild understatement of how good it is, finally someone who actually printed a book the average person can comprehend, even has pictures I can understand. Thanks can't begin to say enough for the recommendation on the book.
You are welcome. Happy New Year.
Randy88, Look into the Test Leads that Dan makes, has a built in shunt, this is also a great tool. Bob
I still have one of those,you're right,pretty slick,reads positive or negative depending on which way you hold it on the wire.I can't remember how many amps on the scale but I use it mostly to tell whether or not the generator/alternator is charging.Ron G
I'll have to ask the old man next time I visit his shop, you can barely walk through it now, Dad's 85... farmer stock all of us.. but I seem to remember he had two, one for reading charging system draw or charge, then one with a much higher scale for starter cable, but I could be wrong.
Haven't found that in the book yet, was actually looking for a chapter about shunts, but there isn't one that I've found yet, maybe he called it something else and I just haven't figured out what it would be, but I have a ways to go to get the whole book read. I've just been reading the chapters that involve my current problem with battery cables and a starter on one of my skid steers.
http://www.vehicleservicepros.com/a...r-leads-product-tool-review-from-dan-Sullivan This the test leads with the built in shunt. The first time I used these I found a bad battery cable, positive to the starter, in 20 seconds. The cable had been replaced 2 months earlier, internal corrosion was the problem, the other mechanic said, "can't be the cable, it's new."
.....so they're talking amps Randy.... let's say the guy just has a volt meter and wants to check both the starter cables and the battery (s). ...weather 24 or 12v acceptable voltage drop (while cranking the engine ) checked at various sundry places would be...consistent. ... I don't know. ...say...20% ?
Probably more like 30%but be the same voltage on the hot leed at each end, battery and starter, while cranking if i remember. ...voltage drop test
An ammeter with different ranges is just a series of shunts for each range,the values depend on what range you choose to measure.Ron G
The only one I would really consider is the Fluke 337. Some of the other ones might not register high enough current for what we do. Off brands often do not register dirty/trashy signals accurately, but Fluke never seems to disappoint. I got mine used on ebay many years ago and I have used it a whole lot. It was about $200 way back then. They cost a lot more new but I would not be scared of used if in good cosmetic condition.
Have had these for some time...sometimes I forget that they are on the shelf. Regards, Bob
Yair . . . ETER Aren't they the ducks nuts! Proper bloody gauges and made in the USA. Cheers.
:usa
"ducks nuts" LMAO...I'm thinking same lines as "the cat's arse"? Still have two ducks on the pond, I'm thinking their nuts are about part of the pond this morning! Regards, Bob
Yair . . . Seriously though. I know I am old fashioned and date back to the stone age but bloody hell . . . That style of gauge used to be standard, what could be more simple? A stand alone system, each unit can be replaced and the operator (provided he/she can read) knows what it is telling. I have been on a couple of machines with opaque/cracked plastic over flashing lights and symbols the meaning of which I didn't have a clue. This modern madness called is "progress". Wish I had some pictures of the dash of the 1960's oil field Peterbuilt, every temperature and pressure on the truck had a gauge all set out in logical sequence, bloody marvellous. Cheers.
Have you checked your cable with an OHM meter? Your cable should have 0.0? ohms. This will tell you how much resistance it has, IE voltage drop. Is the starter not pulling in? or not turning the engine? Do a voltage check across any two points (battery post to cable terminal) I have seen a large voltage drop across them? See if any Electrical contractors in your area might have a 500 amp DC clip on? It has been a long time since I have used one of them. Have the batteries been load tested?
Cat power, yes to all the above and more so, we've installed extra ground wires from the starter to the main frame, just in case for some reason it was losing ground somewhere through the starter, before worrying about starting this thread I found the positive cable was bad via the voltage drop test, so it was replaced. We did a simulated amp test with a carbon pile tester, the only solution I came up with, was even though the starter bench tested fine in all aspects, it sucked too many amps when in the machine. This wasn't the first starter I've had in the same machine, so in essence I got with the luck of the draw, two starters back to back that were bad. I went instead of the factory model of starter, we put on an aftermarket gear reduction starter instead, the only replacement I could to replace the factory starter. We then again did a amp simulated test and with the gear reduction starter in, even though its not idea for amp draw but rather on the high side, its a fraction of the amp draw on the last starter as its cranking. I never bought the new digital amp tester, basically nobody had one when I needed it, so like most, now that I no longer have an urgent need for one, I still haven't ordered one and not sure I will, as one told me, by the time I get to need it in the testing equation, I've already figured out what's bad or have it fixed. Thanks for the help, input and discussion everyone, I really did learn a lot from you all.
I must agree my amp clamp has never been a great help for starter troubleshooting. It is usually all about the voltage drop wherever it is occurring. It is still a great boon for other things like parasitic draw if you have a battery going dead when it should not be.
They sell a digital clamp type meter at Lowes building supply that does Ac and DC amperage up to 400 amps.
https://www.otctools.com/products/heavy-duty-battery-and-electrical-system-diagnostic-tester-1 this is the battery tester that I have and I love it yes a bit pricey but worth it imho I also have a low and a high amp probe that plugs into it and check amp draw it is able to check alternator to. Sorry mine is the 3167HD the 3168 comes with the printer and I don't have that!