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Re: Alternator Grounding [Re: jeebis44] #1425059 04/24/13 11:09 PM 04/24/13 11:09 PM
Joined: Jan 2007 Posts: 7,664 IN A ahy master
ahy master A Joined: Jan 2007 Posts: 7,664 IN	Sounds right to me.

Re: Alternator Grounding [Re: jeebis44] #1425060 04/24/13 11:13 PM 04/24/13 11:13 PM
Joined: Nov 2007 Posts: 21,930 Kirkland, Washington Pacnorthcuda Too Many Posts
Pacnorthcuda Too Many Posts Joined: Nov 2007 Posts: 21,930 Kirkland, Washington	Quote: OK - This is in a relatively stock car, used for daily driving. Rubber mounts are intact, and using a multimeter, found continuity between the alt. case and engine in several points without the ground wire hooked up. That said, I did upgrade the ground wire years ago to about an 8 gauge wire... would like to keep it that way, if for no other reason than vibration may cause issues down the line ( i drive the thing like a a maniac...). Main point of my original question was to find out exactly WHAT needs to be grounded here, and from all posts to now, it's the case. Simple fix IMHO. Tap and screw into the original ground hole in the case and hook up my HD ground wire going right into the pass. side cyl. head. Am I wrong? You're correct. There is nothing wrong in your fix!

Re: Alternator Grounding [Re: jeebis44] #1425061 04/24/13 11:30 PM 04/24/13 11:30 PM
Joined: Jan 2003 Posts: 18,434 UPPER MICHIGAN, MARQUETTE COUN... N NITROUSN I Live Here
NITROUSN I Live Here N Joined: Jan 2003 Posts: 18,434 UPPER MICHIGAN, MARQUETTE COUN...	Quote: OK - This is in a relatively stock car, used for daily driving. Rubber mounts are intact, and using a multimeter, found continuity between the alt. case and engine in several points without the ground wire hooked up. That said, I did upgrade the ground wire years ago to about an 8 gauge wire... would like to keep it that way, if for no other reason than vibration may cause issues down the line ( i drive the thing like a a maniac...). Main point of my original question was to find out exactly WHAT needs to be grounded here, and from all posts to now, it's the case. Simple fix IMHO. Tap and screw into the original ground hole in the case and hook up my HD ground wire going right into the pass. side cyl. head. Am I wrong? You need to ground it as I have said. You will find continuity with a multimeter only because it is finding it through incorrect sources. When you load it the loss of ground will be obvious. That alternator will not work through isolators. You are on the right correct path by using the ground wire to the case. I am done with this post and wish you luck. As far as the uneducated stupid posters that want to argue when they are wrong carry on. I laugh all day long at fools like you.

Re: Alternator Grounding [Re: NITROUSN] #1425062 04/24/13 11:37 PM 04/24/13 11:37 PM
Joined: Jan 2003 Posts: 1,018 Here and now J jeebis44 OP super stock
jeebis44 OP super stock J Joined: Jan 2003 Posts: 1,018 Here and now	What I am reading from these posts is this: ground the alternator case to the engine and the engine to the frame via direct heavy connections (metal-metal heavy gauge wires).

Re: Alternator Grounding [Re: jeebis44] #1425063 04/24/13 11:52 PM 04/24/13 11:52 PM
Joined: Nov 2007 Posts: 21,930 Kirkland, Washington Pacnorthcuda Too Many Posts
Pacnorthcuda Too Many Posts Joined: Nov 2007 Posts: 21,930 Kirkland, Washington	Quote: What I am reading from these posts is this: ground the alternator case to the engine and the engine to the frame via direct heavy connections (metal-metal heavy gauge wires). Pre 80's it was usually grounded vis a the mounting of the unit. If the alternator has isolated mounts then either a mount needs to be electrically bypassed or the grounding stud utilized by wiring to a suitable ground, preferably the engine. You are good to go.

Re: Alternator Grounding [Re: NITROUSN] #1425064 04/25/13 10:48 PM 04/25/13 10:48 PM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	Quote: Quote: Thanks for the replies. So then, I should be able to check for continuity between the case and the engine block and if it's there, I'm good? No.. You want to use a heavy guage wire from that stud to the engine. All the factory cars and trucks had a ground wire. You alternator is mounted with rubber isolators thats why there was a HD wire on the car. I would ask for another correct alternator. Yep that is dead on right. It needs the ground wire because of the rubber mounts on the alt. Most alt bolt right to the block but some such as this use rubber mounts and need the ground wire. You just have to ground the alt case. Ron

Re: Alternator Grounding [Re: jeebis44] #1425065 04/26/13 12:21 AM 04/26/13 12:21 AM
Joined: Jul 2008 Posts: 615 Boise M Moparteacher mopar
Moparteacher mopar M Joined: Jul 2008 Posts: 615 Boise	Once you have installed the alternator, using a continuity test to confirm ground is an inferior test. Perform a voltage drop test with the engine running and alternator at full field. Good results should show no more that .2V to .4V. And, .4V would be high, IMO. Because the alternator case is insulated with the rubber mounts, the ground wire will need to carry the same amount of current that leaves the alternator. So, if the alternator is capable of driving 140 amps then the ground will need to carry 140 amps. Secure the ground wire to an unpainted surface on the engine.

Re: Alternator Grounding [Re: Moparteacher] #1425066 04/26/13 07:06 AM 04/26/13 07:06 AM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni pro stock
cjskotni pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Who knew so many people would become so emaotional about this simple question! In my earlier post, I did not realize this had rubber isolators on the mounts. In that case, you will most definitely need to use the ground wire on that stud. I would use an 8 ga wire or bigger. As said before, run it to the engine block and make sure the engine is grounded well via ground strap. I am used to the old school, "we never use ground wires just ground through the mounts" electrical components. The older non-isolated alternators just grounded through the mounts (no rubber) so that's what people here are probably thinking of....

Re: Alternator Grounding [Re: jeebis44] #1425067 04/26/13 09:44 AM 04/26/13 09:44 AM
Joined: Jun 2008 Posts: 1,822 Colorado D denfireguy top fuel
denfireguy top fuel D Joined: Jun 2008 Posts: 1,822 Colorado	The problem here is that a lot of people have never seen a cop car alternator. Having rebuilt several of these in the day, what Nitrous is saying is spot on. The only way to get a high current connection is through a 10 gauge (8 is way better) direct to the block. I have not seen a cop car alternator in the rebuilt market. That is why we did our own in the day. The only wear items are the bearings, brushes and diodes. When we had a bad alternator, we shot gunned them and replaced all of the above parts. We did have one with a short in the stator and we took that to a motor winding shop (try to find one of those today) to be redone. Craig 2014 Ram 1500 Laramie, 73 Cuda Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango Only previous Non-Mopar: Schwinn Tornado

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