Alternator not charging 802a

[fa35jsf]

So fired up my 802a tonight after some major overhaul work and the alternator doesn’t appear to be charging? Anywhere to start looking first?

Here’s the backstory. I took the head off and cleaned the top of the pistons, heads, and valves. New head gasket. New injectors (the old ones were pretty bad). New fuel lines.

Well at one point in the process I went to go connect my batteries back up and some sparks flew over by the alternator or starter. When I looked I found a piece of the old head gasket over there that looks like it may have shorted.


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[MrShawn305]

So the alternator and the starter are in two different places. Any way to narrow down which one it was that arced out? Either way it sounds like the alternator (maybe the regulator in it) got fried. But before assuming that, check all of the battery and alternator connections. Sometimes when stuff arcs out it burns the connection away. If that makes any sense. Clean up the connections and stuff works again. Start at the beginning, take off all of the electrical connections going to alternator and batteries and clean them. Even if they look good, hit them with a wire brush to make sure. Then install everything good and tight and test.

I had a guy a couple years ago called me to help him with a Jeep Grand Cherokee that he couldn't get started and it left him stranded. He was at a buddy's house and put a new battery, changed the starter 3 times and was about to go get a fuel pump and change it. Asked if I could go take a look at it. So I went over there and took off his battery cables. First, they were loose. When I inspected them, they were all full of crud. I cleaned them up nice and shiny bright as well as the battery terminals and reinstalled properly. Told him to hit the key and it fired right up. Point is, sometimes we overlook the simple stuff and jump to conclusions. Retrace your steps and check everything that you touched. Check the starter cables, check the battery cables. CHECK THE GROUNDS! If there are fusible links, make sure they are connected and in good shape. Then, break out the meter and check voltage from battery positive to alternator output. Make sure you have battery voltage there. If not, follow that wire and find the break in continuity. If you have battery voltage at the alternator output but no charging, you may have a bad regulator.

 

[Ray70]

Have you looked at the battery charging fuse inside the control cube? Gray fuse holder to the left of the AC select switch and just below the DC circuit breaker. F1 if I recall correctly...
I believe it's a 30A fuse.
I would start there.

 

[fa35jsf]

Have you looked at the battery charging fuse inside the control cube? Gray fuse holder to the left of the AC select switch and just below the DC circuit breaker. F1 if I recall correctly...
I believe it's a 30A fuse.
I would start there.

I have not. I’ll have to look there this evening.


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[Guyfang]

I think you will ind the fuse burnt.

 

[fa35jsf]

It was the fuse. Anyone know if it is a fast or slow blow? Maybe a general part number?


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[kloppk]

F03A125V30A is the part number from the -24P TM.

 

[fa35jsf]

F03A125V30A is the part number from the -24P TM.

Yeah I got that. I was looking for a commercial part number but I think I found something on Amazon.


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[fa35jsf]

Now the next problem, I have a cylinder that is not making enough compression to fire off. Puffing white smoke from it. I think I have an exhaust valve sticking. That’s my home at least. The other scenario is either I bent the valve at some point or my piston rings are shot. I really don’t want to have to remove the head. Don’t want to have to buy a new head gasket again


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[Zed254]

Yeah I got that. I was looking for a commercial part number but I think I found something on Amazon.


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https://www.mouser.com/productdetail/bussmann-eaton/bk-abc-30-r?qs=St27ATL478s0HesTffljHg%3D%3D

I think this is the commercial version.....

 

[Light in the Dark]

This fuse looks to be out of stock a lot of places.... time to scour up an equivalent (I realized Im out of backup stock on these, and I want to buy a few more of the fuseholder too).

Edit: Thanks Zed

 

[Light in the Dark]

Should be no issue using this fuse holder, you think? https://www.mouser.com/ProductDetail/504-BK-HKP-R/ Looks to be sized for that same commercial fuse. If I could source just the cap that would be what I need, but the price isn't bad for this whole fuse holder (the one called out in the TM is closer to $50 if you can find it in stock right now). Its normally the cap thats gone for a walk.

 

[fa35jsf]

Bought these on amazon. I’ll let y’all know if they work.

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[Light in the Dark]

I bought up the commercial units listed, and some of the alternate fuse holders. Will advise if they both work properly.

 

[Guyfang]

No reason you can not use that holder.

Another tip. The fuse holder the Military bought was world famous for the cap separating from the internal fuse holder. This fuse holder was used for almost 50 years, and there are about a gazillion part numbers and NSN's. But the darn things never got better. You would turn the cap to the left to take it out, and pull. There in your hand way the plastic part of the cap, the rest of the fuse holder and fuse still in the socket.

 

[Zed254]

Should be no issue using this fuse holder, you think? https://www.mouser.com/ProductDetail/504-BK-HKP-R/

Data sheets both call for 1/4" x 1-1/4" fuse, so looks good to me.

 

[Rikjames92]

Now the next problem, I have a cylinder that is not making enough compression to fire off. Puffing white smoke from it. I think I have an exhaust valve sticking. That’s my home at least. The other scenario is either I bent the valve at some point or my piston rings are shot. I really don’t want to have to remove the head. Don’t want to have to buy a new head gasket again


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Are the valves adjustable? If the clearance is too tight especially on the exhaust valve it will hang open. Not a generator expert but a former engine machinist.

 

[fa35jsf]

Are the valves adjustable? If the clearance is too tight especially on the exhaust valve it will hang open. Not a generator expert but a former engine machinist.

Nope. Not adjustable. I was using a clamp to compress the valve and it slipped off. Bent it


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[Rikjames92]

Nope. Not adjustable. I was using a clamp to compress the valve and it slipped off. Bent it


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Bad luck. This is the place i used to get valves cheap. Its called U.S. Seal. You can give the the dimensions of the valves you need and they can ship them out.1 800-777-6974.

 

[jmenende]

So the alternator and the starter are in two different places. Any way to narrow down which one it was that arced out? Either way it sounds like the alternator (maybe the regulator in it) got fried. But before assuming that, check all of the battery and alternator connections. Sometimes when stuff arcs out it burns the connection away. If that makes any sense. Clean up the connections and stuff works again. Start at the beginning, take off all of the electrical connections going to alternator and batteries and clean them. Even if they look good, hit them with a wire brush to make sure. Then install everything good and tight and test.

I had a guy a couple years ago called me to help him with a Jeep Grand Cherokee that he couldn't get started and it left him stranded. He was at a buddy's house and put a new battery, changed the starter 3 times and was about to go get a fuel pump and change it. Asked if I could go take a look at it. So I went over there and took off his battery cables. First, they were loose. When I inspected them, they were all full of crud. I cleaned them up nice and shiny bright as well as the battery terminals and reinstalled properly. Told him to hit the key and it fired right up. Point is, sometimes we overlook the simple stuff and jump to conclusions. Retrace your steps and check everything that you touched. Check the starter cables, check the battery cables. CHECK THE GROUNDS! If there are fusible links, make sure they are connected and in good shape. Then, break out the meter and check voltage from battery positive to alternator output. Make sure you have battery voltage there. If not, follow that wire and find the break in continuity. If you have battery voltage at the alternator output but no charging, you may have a bad regulator.

This very thing happened to me with my ford transit last week. After swapping batteries and even replacing the alternator it would not start. I went back to the basics. Polished the poles, cable connections and the ground connection to the chassis. Started right up.