Alternator upgrade

[Surprise]

I think my alternator is shot and I'm thinking of stepping up to a 100 amp alternator. Just curious if this can create problems, or is even necessary. The 310 motorhome is pretty much completely stock. Any opinions?

[idroba]

The original is 65 amps if I recall the 310 I had. There are some small benefits in an upgrade, mainly in a bit more capacity to run everything including the dash air at night when the headlights are on. Mine was a bit marginal then.

You might consider replacing the output (generally red) wire from the alternator to wherever it terminates with one with a bit more capacity. I think the original was only a #10. With a 100 amp alternator, a #8 or #6 might be better.

[Keyair]

I thought the standard alternator was 105A..
At least I know that was for the 1986 models, cos its in the specs.
Good advice on the wire specs regardless!

[bkahler]

When an alternator fails while on the road typically the person doing the replacement ends buying an off the self alternator of typically 65 to 70 amps. We had a failure in our old Winnebago while on the road and used what we could find at the local auto parts house. We ended up installing an 85 amp alternator and I'm betting the original that we took out had a higher amperage rating. If the alternator is too small it will fail sooner due to the higher work load its placed under.

Anyway, it's not difficult at all to install a CS-144 140 amp alternator. I just finished the process on my Argosy 454 motor. The CS-144 alternator is one of the later alternators used by GM. They are very robust and have a good reputation. There are two (possibly three) things you have to do to fit the alternator in place of the older smaller style.

The top mount has to have a hole enlarged slightly and the tab bent slightly, a v-belt pulley needs to be fitted in place of the typical serpentine belt found on the CS-144 alternators, and you need a slightly longer v-belt. The last thing would be to do as Idroba suggested which is to upgrade the wiring to a larger size.

I can provide a couple of pictures detailing what needs to be done to the mount and also the length of the replacement v-belt.

Brad

[Jammer]

You should also be able to retrofit an AD-244 alternator although you will need an adapter for the control wires. The AD-244 is newer and has somewhat better cooling and, therefore, longer life.

[cesalie2]

Originally Posted by bkahler

When an alternator fails while on the road typically the person doing the replacement ends buying an off the self alternator of typically 65 to 70 amps. We had a failure in our old Winnebago while on the road and used what we could find at the local auto parts house. We ended up installing an 85 amp alternator and I'm betting the original that we took out had a higher amperage rating. If the alternator is too small it will fail sooner due to the higher work load its placed under.

Anyway, it's not difficult at all to install a CS-144 140 amp alternator. I just finished the process on my Argosy 454 motor. The CS-144 alternator is one of the later alternators used by GM. They are very robust and have a good reputation. There are two (possibly three) things you have to do to fit the alternator in place of the older smaller style.

The top mount has to have a hole enlarged slightly and the tab bent slightly, a v-belt pulley needs to be fitted in place of the typical serpentine belt found on the CS-144 alternators, and you need a slightly longer v-belt. The last thing would be to do as Idroba suggested which is to upgrade the wiring to a larger size.

I can provide a couple of pictures detailing what needs to be done to the mount and also the length of the replacement v-belt.

Brad

Brad,
Please post some pictures and details of what needs to be done to the mount, length of replacement belt, etc...

Thanks,

Daniel

[bkahler]

Daniel,

Hopefully these pictures will show the mods required to install a CS-144 style of alternator on a 454 v-belt style motor. I was a little surprised at how easy it turned out to be. I spent the most time trying to figure out how to bend the tab on the mount and which way to go when enlarging the mounting hole. I ended up over sizing the hole because when I was filing it I got a little confused one time while clamping it in a vise

The first two pictures show the mount as it is bolted to the motor. The only difference between original and after the mod is it sticks up a little higher to provide clearance for the larger diameter alternator.



The next two pictures show the hole that I enlarged and where I had to bend the tab slightly to allow for more rise in the mount.



The next picture shows the the location of the connector that goes to the battery. I did have to change the "clock" position of the alternator to get the connection stud in the position I wanted it to be in. Not hard to do at all.



The original alternator had a spacer that bolted to the back of the alternator and is used inconjunction with the long 6" bolt that screws into the front of the block. The spacer would not bolt to the back of the new alternator due to differences in construction but it is the right length so I went ahead and used it as is. My guess is it bolts to the alternator and was delivered that way from the alternator manufacturer to speed production on the assembly line. There is a threaded hole on the back of the new alternator and if I find the time before installing the motor in the chassis I'll modify the spacer so it can bolt to the alternator. Otherwise I'm not going to worry about it.



New alternator bolted in place. The belt I ended up using is a Gates 7470. It puts the alternator in about mid position for adjustment. One thing I should mention. The top adjustment bolt I used for tightening the alternator in the slot was a 3/8-16 bolt. It's a little loose in the threaded hole of the alternator but seems to hold tight. I will also be using a nut on the back side to ensure it stays tight. I'm not sure if the hole on the alternator had been re-threaded from metric to sae but all three of the alternators I pulled had the same situation.



And the pulley diameter that I used is 2-1/2". I think the pulley I used came from an old alternator I had laying around.



I bought my alternator used from a "you pull it" salvage yard near Pasadena, CA. I pulled three of them for about $20 each. All of them had serpentine belt pulleys but the original pulley from your alternator should fit just fine. While I was looking at vehicles to pull the alternators from I tried to pick the cleanest looking alternators figuring I had better odds of getting a good one. Turns out that two out of the three that I bought were good. The bad one needs a new regulator. So for $60 I got an alternator to install, a spare and a rebuild-able core. I didn't think that was to bad considering the prices new.

I also feel it was a good idea to go with one of these alternators because they are a newer design and from what I could find while researching them is they seem to be very reliable.

I will also be upgrading the wiring from the alternator to the battery (actually battery isolator) so keep that in mind as well if you do the upgrade.

Hope this helps

Brad

[Jammer]

The placement of the ears varies depending on the vehicle, with newer vehicles with serpentine belts using two ears on the bottom and no top ear. Be sure you get the right one.

[Surprise]

I ended up buying a 100amp rebuild that was supposed to be the OEM replacemnt. It's a Remy 20136. After taking out the bad alt, I relized it's completely different and the previous owner did some modifying to make it work. It's make is a Lestek, model 9130. Same case as a Delco 10DN. It is an older gm style alternator (63-72), 105amp, with an external regulator. Not sure why they did that? They use different connections, and mount a little different too. I think I'm just going to use the Remy with internal regulator if I can get the mounting to line up, and nothing is missing.

[Surprise]

I'm trying to add pictures from my tablet but not having any luck.

[bkahler]

Surprise,

I think you'll find that the Lestek was actually installed by Airstream. It's my understanding the Lestek was an upgrade. The 1986 345 that I dismantled had a Lestek alternator installed with upgraded wiring.

Brad

[Jammer]

You can upgrade to a newer alternator pretty easily. There are some places that sell adapter plugs.

[Surprise]

It may have been original but if you look at the picture, someone tapped into the white connector that will fit into the Remy Alt. And that wire runs into the external regulator, and the power is tapped into the pictured solenoid as well.