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Generator voltage output test??


clarkede

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17 hours ago, clarkede said:

No I haven't. Your the first to recommend an actual test like this.  I've got a couple weeks until the new Alternator arrives and I am really curious if the generator works. I wasn't sure what wires I could short to test it.  I saw someone elude to this in some posting, but I didn't want to fry anything by shorting the wrong wire.   I will try this tomorrow evening if it isn't raining too much from Hurricane Ian.  I'll let you know what results show.

I just started the engine with my analog voltage meter connected and then shorted the Field wire to ground(+).  NO increase in voltage at all.  I'm guessing this would indicate that there is a break in the field windings? 

 

For fun, if I were to open up the generator and isolate the wires to the field windings (from the armature and brushes), I'm guessing I would find that there is no continuity through the field windings.  Right?

20220930_170436.jpg

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I received my new 6v positive ground alternator today. Woo Woo.  

Trying to install it and I'm running into a obstruction issue.  I bought the generator with a universal bracket kit hoping that it would fit with minimal work.  I think I can get it to fit, but the bracket elevates the alternator a couple inches and is making it hit the frame piece the comes out under the battery shelf.  Anyone else have this problem or suggestions to fix it?  I could cut it off, but someone might recommend a better bracket that actually retro-fits the vehicle better. 


First picture is the new alternator out of the box with bracket kit.

Second picture is of the generator before removing it.

Third picture shows alternator hitting the squared off metal piece that is usually under the battery tray. I have the battery tray removed to get easier access.

6voltAlternator.jpg

old_generator.jpg

new_alternator.jpg

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1 hour ago, Sam Buchanan said:

An angle grinder with a cut-off wheel is your friend.  :)

Sam, do you remember cutting that bracket off of your Special Deluxe?  I don't see it in your picture with your alternator.

 

I tried turning the original bracket that is mounted to the block upside down to see if that changed anything, but it didn't help at all and wouldn't allow the adapter to swivel at all. So back to the original position shown in the picture.

 

The other options could be to buy a new fan belt that is shorter or some other bracket that might work better.  However, with the smaller pulley diameter, I believe the alternator has to rotate further over to tighten the fan belt.

20221005_222130.jpg

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To lower the new alternator maybe you could remove the stock /blue bracket and mount the new long angle bracket directly to the block with the short offset 90 degree bracket as  it is mounted now.  (Remove the two long offset 90 degree brackets) Might find the clearance you need. 

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11 hours ago, clarkede said:

Sam, do you remember cutting that bracket off of your Special Deluxe?  I don't see it in your picture with your alternator.

 

I tried turning the original bracket that is mounted to the block upside down to see if that changed anything, but it didn't help at all and wouldn't allow the adapter to swivel at all. So back to the original position shown in the picture.

 

The other options could be to buy a new fan belt that is shorter or some other bracket that might work better.  However, with the smaller pulley diameter, I believe the alternator has to rotate further over to tighten the fan belt.

20221005_222130.jpg

 

I'm using a Group 1 battery so there is excess battery tray next to the alternator. A notch was cut out of the tray, a 1" shorter belt was installed and the tray bracket was left intact.

 

I fabricated my bracket, it doesn't raise the alternator as much as yours. I also fabbed an extension for the original adjuster and bolted it to the existing adjuster. Be sure you get the pulleys aligned and don't forget the bolt that attaches the bracket to the water pump penetrates the water jacket and must be sealed!

 

This is one of those deals where you just do whatever you need to do to make it work.  :)

 

image.jpeg.b6ce1b0cd6843a7e38159fb4a2b65d40.jpeg

 

 

 

 

image.jpeg.813887b10e23b4f073e977a5599c9a36.jpeg

Edited by Sam Buchanan
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"Bolt has to be sealed..."  I had to loosen the bolt every time I wanted to adjust the generator/alternator arm. 

 

I replaced the bolt with a stud, with lock washer and nut against the water pump housing,  then a washer, the alternator arm, loose on the stud, another washer, and a nut to keep the arm from falling off, and a cotter pin drilled through the nut and the stud, to keep the nut from falling off.  The arm is free to pivot when I tighten the belt. 

 

974976064_2011alternator010.jpg.c8bbebd49e8720d22e377d5463c15c7d.jpg 

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Yes, something similar has been my plan next time I need to make an adjustment. Thinking I'll put a bushing on the bolt, drill out the arm for the bushing, then seal and tighten the bolt and let the arm 'float' on the bushing. The bottom bracket is what keeps the alternator aligned properly.

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22 hours ago, Sam Buchanan said:

 

I'm using a Group 1 battery so there is excess battery tray next to the alternator. A notch was cut out of the tray, a 1" shorter belt was installed and the tray bracket was left intact.

 

I fabricated my bracket, it doesn't raise the alternator as much as yours. I also fabbed an extension for the original adjuster and bolted it to the existing adjuster. Be sure you get the pulleys aligned and don't forget the bolt that attaches the bracket to the water pump penetrates the water jacket and must be sealed!

 

This is one of those deals where you just do whatever you need to do to make it work.  :)

 

image.jpeg.b6ce1b0cd6843a7e38159fb4a2b65d40.jpeg

 

 

 

 

image.jpeg.813887b10e23b4f073e977a5599c9a36.jpeg

All great points.  I wish I could fabricate something like you have but I'm not familiar with welding yet.  I feel like that could be in my near-future though. 

 

I can't seem to directly connect the alternator to the original bracket because it would completely mess up the pulley alignment which is why I need some sort of adapter bracket in the first place.  My goal it to figure something out today and get the car running with the alternator.  I think I will head over to one of the local auto stores and see if they have any random brackets that I could use instead of the universal one which raises the height about 2 inches from the original bracket.  Also, I like the idea of shortening the belt just a little.  I'm going to look at the existing adapter bracket again and see if the shorter belt is really all that I need.  I'll need to put the battery tray back in and see if it isn't only the fender bracket that is in the way.

 

In the end, I agree that I just need to get something in that works.

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23 hours ago, Sniper said:

Here's how I mounted my 12v Alternator (87 Diplomat donor), it might work fo you?

 

http://www.yourolddad.com/12-volt-conversion

Thanks for sharing.  Last night I looked through all of your Projects.  You've put a lot of attention to detail which is great - especially the carburetor rebuild.  I've done that rebuild a few times and the detail (with pictures) that you have reminds me of all the little things you have to be careful of.  I was thinking about buying the electrical harness you bough but I decided to custom redo my wiring completely since I was adding in several fuse boxes.

 

Ok, back to the alternator problem...

 

It looks like you were able to use the original bracket with the threaded rod and a few washers (I lost count) on the top bracket.  And you've gone to 12v.

 

Photo 1 shows that the alternator I bought has a much larger base attachment than yours and it throws off the pulley alignment.

Photo 2 shows how I've configured the universal adapter with the original bracket to get the pulley where it needs to be.

Photo 3 shows that bracket brings the alternator over about an inch to be in the right position.

 

I'll post more pictures of what I come up with today.

 

alternator1.jpg

alternator2.jpg

alternator3.jpg

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22 hours ago, DonaldSmith said:

"Bolt has to be sealed..."  I had to loosen the bolt every time I wanted to adjust the generator/alternator arm. 

 

I replaced the bolt with a stud, with lock washer and nut against the water pump housing,  then a washer, the alternator arm, loose on the stud, another washer, and a nut to keep the arm from falling off, and a cotter pin drilled through the nut and the stud, to keep the nut from falling off.  The arm is free to pivot when I tighten the belt. 

 

974976064_2011alternator010.jpg.c8bbebd49e8720d22e377d5463c15c7d.jpg 

 

It looks like your alternator might be a little smaller than the one that I've got (although pictures and angles can be deceiving) and the fact that you are able to use the original bracket with the rod, lowers your alternator enough to not hit the battery bracket at the bottom center of your photo (where the battery hold-down bolt connects). I'm jealous - I wish mine were that easy.   But, I will figure it out. 

 

Thanks for the pictures, as they are all giving me great ideas.

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When i got the alternator in 2011, I tried using the all-purpose,  all-adjustable bracket, but everything seemed to be cobbled and too high.   

I compared the generator pulley with the new alternator pulley in regard to the existing generator bracket, and notched the alternator for the wing of the bracket.   A series of washers, couplings, nuts and bolts completed the installation. 

 

image.jpeg.81f08d78073d96d98f318bbd58599fd7.jpeg

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4 minutes ago, DonaldSmith said:

When i got the alternator in 2011, I tried using the all-purpose,  all-adjustable bracket, but everything seemed to be cobbled and too high.   

I compared the generator pulley with the new alternator pulley in regard to the existing generator bracket, and notched the alternator for the wing of the bracket.   A series of washers, couplings, nuts and bolts completed the installation. 

 

image.jpeg.81f08d78073d96d98f318bbd58599fd7.jpeg

 

Oh wow... I wouldn't have thought you could do that.  Did you use an angle grinder with a cut off wheel t

o do it?  Was it hard to do?

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15 minutes ago, clarkede said:

Also, probably a dumb question, but if the alternator is supported at top and bottom, is there a significant reason for the bolt to continue to the rear bracket hole (long bolt)?

 

It's good practice to incorporate both ears of the original bracket. This reduces twisting load on both the alternator and bracket. The belt is trying to twist the alternator and could eventually fail either one if not properly supported. A single length of steel tubing between the rear alternator ear and the bracket could be used as a spacer on a long bolt instead of the collection of nuts. But this looks like a good solution.  :)

Edited by Sam Buchanan
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I took advice and cut into my alternator so that I could mount it using the original mounting bracket. 

 

To do this I needed to measure carefully to properly distance to the pulley (on original generator) so it would align with the other pulleys and fan belt (Image 1).

 

Image 2 - I determined where to cut into the alternator.

Image 3&4 - I used an angle grinder with a metal grinding wheel and cut into the new alternators aluminum frame quite easily (images 3&4). 

Image 5 - I was able to make a slit right where the original bracket would need to be inserted (image 5). 

I also needed to enlarge the holes in the existing bracket for the larger bolt to go through.  While I had everything off I also used the angle grinder to clean all the surfaces so that I would be sure to get a good ground (since that is where I connect the battery ground).

Image 6 - the alternator fits and I did not need to cut the battery tray bracket.  The alternator is below the battery tray bracket about 3/4 of an inch and the original 50 inch V-Belt fits just fine.  I have not put a permanent bolt in bottom yet since the bolt I have it too short.  I need to get another one.

gen1.jpg

image2.jpgimage3.jpgimage4.jpg

image5.jpg

image6.jpg

 

image1.jpg

Edited by clarkede
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I'm having the same issues with charging and generator output. I've decided to buy a 6v alternator too, even if it won't look stock. I'd much rather drive the car! Thanks for all the advice and tips!

 

 

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14 hours ago, DonaldSmith said:

I cut the notch in my alternator with a hand-held hacksaw.  The notch was wide enough that  I could use washers for a final back-and-forth adjustment. 

I spliced something together to extend the adjusting arm.

 

734224592_newextensiontoalternatorarm.JPG.bfca9ec73a621982084f6079a44d4117.JPG

 

I like your idea and I searched all my parts bins to find something like it.  Well - I did it!!!  I found a few smaller brackets and fastened them all together to make an arch shaped bracket. I connected my brackets at the other end so I didn't need to pull the bolt out of the water pump to remove the original bracket.    I also had an old alternator spacer that I used instead of a stack of washers to properly space the original bracket to the new brackets.  The alignment is perfect.  I also used the idea to use a threaded rod that goes through everything at the bottom.  Best of all, the alternator is very securely fastened now. I'm super happy.   I've also wired the alternator directly to the ammeter and removed the voltage regulator (for now).  I also used the angle grinder to clean up all of the parts that need to be properly grounded (clean bare-metal connections are the key). 

 

I haven't started the engine yet because I have a few little details to clean up.  I will do that tomorrow morning and then fire it up and see how the charging works.  I am fairly certain that everything will work great (presuming the alternator was good and not DOA - which would really suck).  I'll post my results tomorrow.

 

Oh, I plan to also test the old generator before storing it away.  I am certain that I could run it as a motor, but for some reason it would not output any voltage when running as a generator.  I will confirm this though a couple tests and post those results in a day or two in case it helps someone else to troubleshoot their generator. 

image8.jpg

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On 10/8/2022 at 9:37 PM, LeBaron said:

I'm having the same issues with charging and generator output. I've decided to buy a 6v alternator too, even if it won't look stock. I'd much rather drive the car! Thanks for all the advice and tips!

 

 

 That is the exact issue that I was having.  My generator was not charging the battery and I had to keep charging the battery every time I went out and came back - especially if i used the head lights.  I didn't feel comfortable going out and making several stops for fear of the starter not having enough juice.  I did all kinds of diagnostics and was just going crazy with the generator being the last thing that seemed to be the issue.  So, after reading all about alternators it just seemed like the thing to do.  I'm glad I have the resources to be able to do it.  I will test it out tomorrow and see how well it performs.  :)

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