help! broken down! Alternator Issues

Topic: help! broken down! Alternator Issues (Read 4751 times) previous topic - next topic

Re: help! broken down!

Reply #100 – May 12, 2016, 01:04:50 pm

Brett,
Thanks again. To make this crystal clear for us non-tech folks, the IGN and sense wire are the two small terminals between the alternator + terminal and the other large lug on the opposite side?

Re: help! broken down!

Reply #101 – May 12, 2016, 01:10:22 pm

Quote from: Peter & Beth – May 12, 2016, 01:04:50 pm

Brett,
Thanks again. To make this crystal clear for us non-tech folks, the IGN and sense wire are the two small terminals between the alternator + terminal and the other large lug on the opposite side?

Correct. The 4 terminals on a 4 wire alternator are:

B+= large red to center lug of battery isolator

Ground= to chassis ground-- usually black

Sense wire (one of the two small terminals)= small gauge wire to chassis battery-- can go to chassis battery terminal of isolator, starter, or chassis battery, as all these read exactly the same (assuming connections are clean and tight).

IGN (the other small terminal) wired to an "ignition hot" source. It has 12+ VDC when the ignition is on. NOTE: not present on all alternators.

Note: not all alternators are 4 wire.

Re: help! broken down!

Reply #102 – May 12, 2016, 01:33:12 pm

At this point I would probe IGN and SENSE at the alternator myself with a voltmeter before having blind faith in the bad alternator diagnosis.

Re: help! broken down!

Reply #103 – May 12, 2016, 01:36:50 pm

Brett, I do hope they did determine that, but there is no record of it in their notes :/ The wiring diagram we have only shows 3 wires, so that may be where they were confused. Wish you were here and part of these FMCA meetings they have going on this week. I'm sure you would have it figured out real fast.
We may even run through the troubleshooting steps in that document from Powerline ourselves when we get to Michigan to see what we come up with before removing the alternator...
Thanks Peter and Brett for all of your knowledge. Should I change the title of the thread to "Alternator trouble" or is that something the mods need to do? There is a lot of good info here, I think.

Re: help! broken down!

Reply #104 – May 12, 2016, 01:46:34 pm

Can you take a picture of the alternator, showing the 3 or 4 terminals? Perhaps a closeup of the model number?

You have an invaluable resource here on his forum, and we all want to help.

Re: help! broken down!

Reply #105 – May 12, 2016, 01:47:54 pm

Quote from: Walkerfam7 – May 12, 2016, 01:36:50 pm

We may even run through the troubleshooting steps in that document from Powerline ourselves when we get to Michigan to see what we come up with before removing the alternator...

If you (or anyone in your group of friends) know a good "shade-tree mechanic" with good troubleshooting skills that would be an excellent idea. From what you've told us there's been a lack of high-quality troubleshooting so far.

Re: help! broken down! Alternator Issues

Reply #106 – May 12, 2016, 02:41:04 pm

Quote from: Walkerfam7 – May 12, 2016, 01:36:50 pm

Should I change the title of the thread to "Alternator trouble" or is that something the mods need to do? There is a lot of good info here, I think.

Done

Re: help! broken down! Alternator Issues

Reply #107 – May 12, 2016, 03:26:35 pm

Quote from: Tom Lang – May 12, 2016, 01:46:34 pm

Can you take a picture of the alternator, showing the 3 or 4 terminals? Perhaps a closeup of the model number?

You have an invaluable resource here on his forum, and we all want to help.

Tom, I am sure I can get a picture posted on here in just a bit. Right now we have two little ones napping in our bed right over the alternator...lol.

Re: help! broken down!

Reply #108 – May 12, 2016, 04:14:59 pm

Quote from: D.J. Osborn – May 12, 2016, 01:47:54 pm

If you (or anyone in your group of friends) know a good "shade-tree mechanic" with good troubleshooting skills that would be an excellent idea. From what you've told us there's been a lack of high-quality troubleshooting so far.

Both Trent, myself and Cummins observed the same voltage results. The terminals on the back of the alternator have corrosion. Perhaps a good cleaning could make the reading s abit clearer.

Re: help! broken down! Alternator Issues

Reply #109 – May 12, 2016, 04:38:24 pm

Not to hijack OP thread, a good reminder for all of us to take a close up look at the connections that aren't so easily seen on the back of the alternator. I'll be cleaning mine for sure... 4 wire.

Anyone know what the smaller empty studs above are for?

Re: help! broken down! Alternator Issues

Reply #110 – May 12, 2016, 04:59:23 pm

Corrosion in that area is a problem. When I had the alternator replaced several years back I coated the terminals with dielectric grease and after all that time the terminals look like the day they were installed.

Re: help! broken down! Alternator Issues

Reply #111 – May 12, 2016, 08:14:47 pm

Quote from: Doug W. – May 12, 2016, 04:38:24 pm

Anyone know what the smaller empty studs above are for?

Doug,
If you had a standard alternator like on a class 8 truck your diode trio would be hooked up here. They are long through bolts that go completely through the brush holder and your pos. and neg. rectifier connect to them inside. They are also there for test points.

Pamela & Mike

Re: help! broken down! Alternator Issues

Reply #112 – May 13, 2016, 10:53:14 am

Any competent alternator shop can repair that powerline. There is one here near me, complete rebuild, brushes, bearings etc was about 100 bucks five years ago. Look local before you pay shipping charges both ways to Texas.
JMHO
Gary B

Re: help! broken down! Alternator Issues

Reply #113 – May 16, 2016, 01:03:36 pm

Ok. We are getting ready to do some troubleshooting before we just give up on the alternator and pull it to be repaired. Trent's dad has pulled out his oscilloscope for what reasons I have no idea, but he's the engineer, not me. Lol. Here is the picture that I promised I would post so you guys can see the particular alternator we are working with.

Re: help! broken down! Alternator Issues

Reply #114 – May 16, 2016, 01:24:16 pm

Looks like the original alternator. It will be easy to check with a multimeter if it is producing power, either at the alternator or at your isolator. At 21 years old, I wouldn't be surprised if it is dead, mine died about 4 years ago. Charging the large RV battery banks is pretty rough on our alternators.

Re: help! broken down! Alternator Issues

Reply #115 – May 16, 2016, 01:30:11 pm

Quote from: Walkerfam7 – May 16, 2016, 01:03:36 pm

Ok. We are getting ready to do some troubleshooting before we just give up on the alternator and pull it to be repaired. Trent's dad has pulled out his oscilloscope for what reasons I have no idea, but he's the engineer, not me. Lol. Here is the picture that I promised I would post so you guys can see the particular alternator we are working with.

I'm really not certain why an oscilloscope would be required. Basic troubleshooting with a volt-ohm meter should be sufficient.

I would recommend removing, cleaning and re-connecting each electrical connection one at a time, making sure the new connections are clean and tight. Then I would check voltages to see if the batteries are being charged. If they are not, then I would label each connection and remove the alternator.

I would then go to a local shop to have it checked and possibly rebuilt locally. I have the impression you're in the Grand Rapids area. If so, then I found a shop ADEMA Electric that looks as if it should be able to handle that. If you have to ship it for repair then the shipping charges could be pretty high, and so I personally would go with a reputable local shop if possible.

Re: help! broken down! Alternator Issues

Reply #116 – May 16, 2016, 01:36:26 pm

David, I think that is exactly where we are at on this too. I have already been looking up local shops as well... That does look like a good one that I had not seen yet. I will check them out.

Re: help! broken down! Alternator Issues

Reply #117 – May 16, 2016, 01:43:51 pm

Is there not a mobile "sparky" that will come to your site? I thought your alt wiring was a little different than most, but if you've got the specs could be cheaper in the long run to have someone come out.

Re: help! broken down! Alternator Issues

Reply #118 – May 16, 2016, 01:48:51 pm

If you take the alternator to any shop, for any reason, be sure you make them understand that your vehicle has 2 separate battery banks and a diode-based battery isolator. For some reason (that I don't understand) this is very confusing to shops that usually only deal with trucks. You don't want them making any modifications to the alternator - you just want it restored to original operating condition. More than one Foretravel alternator has been screwed up by well-meaning but clueless rebuilders.

Re: help! broken down! Alternator Issues

Reply #119 – May 16, 2016, 02:01:51 pm

Quote from: Chuck & Jeannie – May 16, 2016, 01:48:51 pm

If you take the alternator to any shop, for any reason, be sure you make them understand that your vehicle has 2 separate battery banks and a diode-based battery isolator.

Excellent point! I should have emphasized it, and I didn't. I'm thankful you did!!

Re: help! broken down! Alternator Issues

Reply #120 – May 16, 2016, 02:28:58 pm

Chuck...thanks for that tip! That is good info...don't want anyone ruining the alternator...

Re: help! broken down! Alternator Issues

Reply #121 – May 16, 2016, 03:09:43 pm

The photo posted by the walkers does not look like a Series 25 Powerline (see diagram in manual linked in reply #106 above).

Their photo shows a simple "self-exciting" alternator hookup. There is no "IGN" (hot with ignition on) wire (the small jumper wire going under the cover plate may provide that function). The small gauge wire going to the "Voltage Sensing Terminal" should read "Start Battery" voltage at all times. The big cable on the left is ground (-). The big output cable on the right goes to the center post on the isolator. That's all there is to it...

It should take about 5 minutes to check the operation of this alternator, using a simple multimeter.

Check (-) ground cable is good. Check voltage on "Sense" wire is the same voltage as the start battery positive (+) terminal. With the engine off, the big (+) cable on the right should show the same voltage as the center post on the isolator (see note below). When the engine is started, the voltage on the big (+) cable on the right should jump up to around 14 volts. If it does, the alternator is working.

Note: With the engine off, you may actually read some voltage on the center post of the isolator. In a perfect world, under these conditions, a diode based isolator should show zero voltage on the center post. If any is present, it is attributed to "leakage backwards through the diodes". Some will say this means the isolator is faulty...others will say this is "phantom" voltage and does not affect the functioning of the isolator. I'm in the second camp, because this is how my isolator behaves. Since it ALSO does its job just fine, I don't worry about it. I didn't even want to mention this whole "Leaky Diode" anomaly, to avoid confusing the present issue. But somebody will probably bring it up, so...I did.

Re: help! broken down! Alternator Issues

Reply #122 – May 16, 2016, 04:26:53 pm

Their isolator, alternator and regulator should be the same as mine if it has not been modified by a PO.
I have a 4 post isolator.
here are a few pics of mine and a couple off of the internet for reference.
Remove the regulator and check brush contacts if you have not already done so.
When my alternator quit it was only the regulator ....... alternator was fine.... repaired with new regulator for less than $200

Re: help! broken down! Alternator Issues

Reply #123 – May 16, 2016, 05:01:10 pm

If all else fails................
Here is one that might work...... our engines are different so maybe not.......?

Poweline High Performance Alternator 14V 10 401 Heavy Duty Lightly Used | eBay

Re: help! broken down! Alternator Issues

Reply #124 – May 16, 2016, 05:17:22 pm

I just had a similar problem with my alternator coming back from Foretravel in Texas. I was able to run during the day without lights with my generator running keeping the charge at 12 without any issues, I had a new regulator put in and works great now. If I had included daytime running lights, the generator would not have been enough to keep the voltage at 12 to get home without incident.

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