Author	[Modern View]
pconnie.ks 09-25-2012 17:54:56 67.72.98.45 Report to Moderator	Is there a way to bench test a coil [Reply]   [No Email]
JMOR 09-26-2012 10:25:03 72.181.173.171 Report to Moderator	Re: 12 v coil in reply to ken and dogs, 09-25-2012 17:54:56   Quoting Removed, click Modern View to seeSame here. Got a box sitting here under the bench with 7 in it. [Reply]  [No Email]
rossow (mn) 09-26-2012 10:14:42 134.29.14.172 Report to Moderator	Re: 12 v coil in reply to pconnie.ks, 09-25-2012 17:54:56   Not relevant to technically testing a coil, but... Both of my 8Ns have been converted to 12-volt, so when I go to car swap meets, yard sales, etc., I pick up new/used round coils when they're cheap, just to have a spare or two or three available for "testing" purposes. Got one new in box for $1 this summer, and another "slightly used" for $3 at a swap meet a couple of weekends ago. The same coils fit my N's as fit my old Novas and Chevelles and '55-57's, so it's easy to swap them around to pinpoint a bad coil. Pretty sloppy approach, perhaps, but it works for me at very little expense or effort. [Reply]  [No Email]
JMOR 09-26-2012 08:04:52 72.181.173.171 Report to Moderator	Re: 12 v coil in reply to rickdeere, 09-25-2012 17:54:56   Quoting Removed, click Modern View to seeThere are all kinds of ways to rig up something to simulate the distributor/condenser/points opening & closing and observe a HV spark (something of a coil test), but unless you have a shop full of "stuff" & want to spend the time, sticking it back on the tractor will be the quickest & easiest you can do. Keep in mind that most parts supply places have a no return policy on electrical parts........because they, too, don't know how to verify that the part is still good after you have had it out of their sight. [Reply]  [No Email]
JMOR 09-25-2012 21:02:55 72.181.173.171 Report to Moderator	Re: 12 v coil in reply to ASEguy, 09-25-2012 17:54:56   Quoting Removed, click Modern View to seeI know...spank my hand! :twisted: [Reply]  [No Email]
Royse 09-25-2012 20:43:50 69.36.49.151 Report to Moderator	Re: 12 v coil in reply to pconnie.ks, 09-25-2012 17:54:56   Quoting Removed, click Modern View to see BAD JMOR! BAD! :lol: [Reply]  [No Email]
JMOR 09-25-2012 19:21:42 72.181.173.171 Report to Moderator	Re: 12 v coil in reply to HCooke, 09-25-2012 17:54:56   Quoting Removed, click Modern View to seeI know that I shouldn't answer for him, but I can't help myself this evening! "Well, it is like this...I don't know or really understand what that black thing does & I am suspicious of the unknown, so I think the problem is the black thing." How am I doing? :wink: [Reply]  [No Email]
Bruce (VA) 09-26-2012 07:29:47 24.125.80.178 Report to Moderator	Re: 12 v coil in reply to JMOR, 09-25-2012 19:21:42   LMAO! I'll save this response for later use.......... :) [Reply]  [No Email]
Bruce (VA) 09-25-2012 18:49:09 24.125.80.178 Report to Moderator	Re: 12 v coil in reply to pconnie.ks, 09-25-2012 17:54:56   Coil problems are difficult to diagnose. For starters, round coils are pretty robust & square coils aren’t (because of the difference in insulation used), but neither one will hold up to a poorly done 12v conversion that allows too much current to the coil or leaving the key on (see tip # 38). Too much current creates heat which melts the insulation. Insufficient resistance in a 12v conversion will do the same thing. Rarely do coils just “go bad.” As others have said, there are a few ways to see if a coil is bad, but it’s not possible to determine if a coil is good w/o some expensive testing equipment. If you detect a dead short or high resistance in the coil w/ an ohm meter, it’s bad. If it’s cracked, it’s bad. If a sidemount coil w/ battery voltage to the primary will not jump a ¼” gap from the secondary wire to the block, it’s bad. But, here is the hard part: even if you do not detect a short, even if it will produce a spark, even if it’s not cracked, that doesn’t mean the coil will work when it’s hot & under a load. So, it’s a process of elimination. If the tractor starts & runs fine for 30 minutes or an hour then cuts off & refuses to re-start, and you checked for spark at the plugs & it had no spark at all, AND you have the correct voltage at the coil that’s a good sign that you have a bad coil. Let it cool off, restart it & if you have a good spark, odds are it’s a bad coil. But, even then, you might end up w/ a spare coil on the shelf! Bottom line.......coils do go bad, but I'll venture a guess that 75% of new N coils sold today are sold to folks who do not understand how to diagnose a poor spark problem or how a coil works. So, for those who don’t know any better, in a no spark situation the first suspect is usually the coil……and, more often than not, it isn’t the problem. So, what problem are you having that leads you to suspect a coil failure? 50 Tips [Reply]  [No Email]
pconnie 09-26-2012 07:40:02 67.72.98.45 Report to Moderator	Re: 12 v coil in reply to Bruce (VA), 09-25-2012 18:49:09   using the 4000 backhoe..sputtered then died..no spark..no spark at points..installed new coil..no spark at points..spark at dizzy terminal..pulled terminal.. insulator corner was broke off..replaced insulator..back working..guy at oreillys shook the old coil..determined it is bad..new coil has fluid slushing inside..old coil does not..trying to decide if i want to see if oreillys will take new coil back..thats why i thought i might be able to bench test to determine if old coil is good without replacing it on the tractor..im ate up with arthritis..nothin is funny bout this..thanks for all interest phil [Reply]  [No Email]
Dell (WA) 09-26-2012 08:52:57 71.217.25.153 Report to Moderator	Re: 12 v coil in reply to pconnie, 09-26-2012 07:40:02   Phil.......You first asked "Is there a way to bench test a coil". I flunked mind reading, just ask my ex-wife of 32-yrs. Now you explain WHY you are concerned 'cuz the insulative oil inside the round can coil "sloshes". As a general rule, yer roundcan coil should NOT slosh. Taker back and complain. Don't be surprized iff'n they won't exchange. Usually parts stores have a sign on the wall "NO ELECTRICAL EXCHANGE" .......the mindless Dell [Reply]  [No Email]
Hobo,NC 09-25-2012 18:13:01 98.17.83.160 Report to Moderator	Re: 12 v coil in reply to Billie R. Smith, 09-25-2012 17:54:56   If an ohmmeter shows an open in either circuit it is bad. If a ohmmeter shows its good it still can be bad... :twisted: Its a rare event to see a ohmmeter confirm a kill.... [Reply]  [No Email]
soundguy 09-25-2012 18:11:31 173.104.190.114 Report to Moderator	Re: 12 v coil in reply to pconnie.ks, 09-25-2012 17:54:56   about the same as with a tractor. of course you can get fancy with a switch, condensor and spark gap too.. [Reply]  [No Email]
teddy52food 09-25-2012 18:00:02 184.94.175.179 Report to Moderator	Re: 12 v coil in reply to pconnie.ks, 09-25-2012 17:54:56   Yes, with a coil tester. If an ohmeter shows an open in either circuit it is bad. [Reply]  [No Email]