Capacitor question on alternator

[CamoCUCV]

Ok so Im rebuilding my Passenger side alternator on my 84 M1008. (NOT GROUNDED UNIT)
Is the INTERNAL capacitor the same as the one on the outside connected to the ground?

I hope this question makes since. I would like to get this back together tonight.

Only one came with my kit. Do I have to order it separate? Or.........I have another one that is new out of another rebuild kit I could use it?

SO are they the same is my real question?


THANKS

 

[juanprado]

It is there for radio noise suppression.

 

[Warthog]

The one on the outside is not required unless you have a military radio setup. I would have to look in the parts manual to see if they as the same.

 

[NovacaineFix]

If you are referring to this one:


Then like the others said, it is not needed. Can't hurt to have it, will cut down on radio noise being generated from that alternator, but not needed. If you worry about it, you can always get one and install it later.

 

[CamoCUCV]

Awesome! Thank You,
I did manage to get them both back together and back on the truck. The passenger side was putting out 14.3V awesome right! The driver side still isn't working... dang. So I'm thinking I made a mistake. When I was rebuilding the drivers side the capacitor inside was the square stile. I guess it has been rebuilt before? I thought the original was round from what you guys have said. So I assume the person that rebuilt it last time discarded the little retainer that held the round one because the square one doesn't need it. So I decided to just use the old one and kept the new one thinking I might use it on the back of the passenger side. So I guess my only choice now is to take it apart and put the new one in. Dang double dang.
But the front battery wasn't charged up good it was at 11.58 so before I take it apart again I will make sure my belt is tight and battery is charged.
Now if it still don't work I'm left to believe my ignition powered excite wire might be dropping out? I need to check it with a load I guess not just the voltmeter. Or my larger hot wire is dropping out. Any other suggestions? I should probably do what I know first before I drive myself batty thinking about it. My dash lights still are not working.

 

[Tow4]

Did you check the dash indicator lights to see if the bulbs are good?

 

[CamoCUCV]

I did clean up the contacts and replaced the bulb I trace the power all the way doesn't make since. Must be a ground issue. I was thinking maybe the I need to put it all back together. I have it kind of hanging out. I can follow the power all the way from the fuse to the alternator but no light? That's why Im leaning towards the possibility its dropping out under load. FUN FUN FUN

 

[Warthog]

The drivers side alternator does require a ground wire from the alternator ground out to the block.

You also need to check the voltages on the two pin excitir plug.

 

[CamoCUCV]

The drivers side alternator does require a ground wire from the alternator ground out to the block.

You also need to check the voltages on the two pin excitir plug.

Warthog,

I think I confused everyone, I was responding to a response "if I had checked the bulb". I have followed all the wiring diagrams you provided and traced the circuit from fuse on heater to ignition to dash to firewall to alternator , The voltage is there. And on the large power wire as well on the alternator, Im grounded to the block on the alternator, and I rebuilt the alternator last night. I didn't replace the capacitor when I rebuilt it. I think that's the mistake. Earlier I said it might be a ground issue I was referring to the bulb still not illuminating. I have the instrument cluster/ light board just hanging out on the steering column.

Sorry I haven't figured out how to respond to someone like yall do with the quoted text.

Do you think it could be that stupid square capacitor I used instead of replacing it with the round one when I rebuilt it?

 

[juanprado]

both capacitors are for the same thing, radio noise whine suppression. Should have nothing to do with the charging.

 

[CamoCUCV]

both capacitors are for the same thing, radio noise whine suppression. Should have nothing to do with the charging.

Ok got it, thanks, I installed both alternators last night after rebuilding both. The passenger side I replaced the internal cap with a new one and used the old one on the outside. That alternator works fine . But the drivers side I still is not working. When I rebuilt it I did not replace the cap inside because there was a square block cap instead of a round one. I got a round one in the rebuild kit. The rebuild kit didn't come with a retainer for holding the cap down. So I left the old square block cap in. I think that was a mistake. I will open it up again and put the round one in and make my own retainer to hold it in place inside.

 

[CamoCUCV]

Thanks for all the help! They are both working now! SO I was going to take it off and change the cap inside. Once I got it off I noticed I had left the brush retaining rod in it! SO I removed the rod and quickly remounted it............. still nothing! Talk about a let down. SO I removed it again took it apart put the new cap in it. Then reinstalled it and still nothing. So I took it off and took it up to Advance Auto to bench test it. Tested good! OK SO I reinstalled it and said to myself.... Ive already traced the entire circuit and checked every point and connection. I must have something wired wrong. I remembered that the kid at advance auto had a hard time making ground to test it. He was hooking up to the post I told him was ground but it didn't work he had to ground to the casing. So I went back to the picture I had from when I removed it the first time from the truck. I had not reviewed the pic just because I remembered how it was wired and didn't need to. I use my phone a lot of times instead of writing it down. I reviewed the pic and I had hooked it up the same as I took it off. Then it hit me it wasn't working when I took it off.... hummmm?. So I went to the wiring diagrams and sure enough the ground wasn't landed on the right post. I had it landed on the bolt in the back that isn't used . Well it is used to hold the external cap retaining clip on the passenger side. But on the drivers side it isn't used. The ground lands with the small black wire. So I fixed it and managed to completely rejuvenate the entire circuit in the process. It needed it anyway.

Thank You guys couldn't have done it without you, Or wouldn't have even tried.

 

[Tow4]

Glad you got it figured out.

FYI, operating the alternator with the brush retaining pin installed usually destroys the regulator among other things. You are lucky you had it hooked up wrong and discovered the brush retaining pin first.

 

[Starlight]

If you are referring to this one:
View attachment 620148

Then like the others said, it is not needed. Can't hurt to have it, will cut down on radio noise being generated from that alternator, but not needed. If you worry about it, you can always get one and install it later.

Great thread I'm trying to get the noise out of my stereo system I believe it's when I change the alternator I did not put the capacitor back or the people that did the work. Can this be bought at any auto store? Thanks so much Captain T

 

[nyoffroad]

Great thread I'm trying to get the noise out of my stereo system I believe it's when I change the alternator I did not put the capacitor back or the people that did the work. Can this be bought at any auto store? Thanks so much Captain T

Back in the old days (kinda like this thread LOL) we would use any old condenser from when we changed the points and attach it to the alternator to kill the whine, IIRC sometimes to the radio itself. All the condenser does is 'leak' a little bit of power to ground and thus kills the whine, how I have know idea.

 

[Starlight]

Back in the old days (kinda like this thread LOL) we would use any old condenser from when we changed the points and attach it to the alternator to kill the whine, IIRC sometimes to the radio itself. All the condenser does is 'leak' a little bit of power to ground and thus kills the whine, how I have know idea.

Thanks ! Can I just buy any 12 v capacitor at auto store ? Thx, T

 

[juanprado]

Standard Ignition makes a few different models that Rock or O'reilly can get for you.

See this link and then you can click on each part number to get specifics. They were real common maybe 60-90's but not used in modern cars.

STANDARD MOTOR PRODUCTS Radio Capacitor Electrical Parts | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

 

[Starlight]

If you are referring to this one:
View attachment 620148

Then like the others said, it is not needed. Can't hurt to have it, will cut down on radio noise being generated from that alternator, but not needed. If you worry about it, you can always get one and install it later.

Hey Nova, this is Captain T. I must have replaced his alternator at some point down the road and take it off the sound filter capacitor for lack of a better word. Can these be bought at any auto store? I know it says you don't need them but I do have a stereo in here and the feedback is terrible from the alternator so I'm thinking I did not put the old one back on the new alternator at some point in time. Thank you so much, Captain T

 

[juanprado]

Read post #17