Electrical Problem (alternators?)

I got my blazer running after it has been sitting for no telling how long and have only driven it twice about 10 miles each time. It did fine both times. Today I drove it to the store and when I went to leave it would not start and the batteries drained very quickly until the starter began to click. The batteries where hooked up tight and it was at operating temperature so it wasn't cold. The GEN 1 light is on all the time and the GEN 2 light began to flicker on the way to the store. I do not know what the GEN lights mean though, because the battery gauge was in the green the whole time. I am charging the batteries to go retrieve the truck later but need some help with the lights and possible alternator problems. Any help???

Typical troubles. Long time sitting, flickering gen lights.

I suggest you just have them both rebuilt by a good local alternator shop, and go from there. (new regulator, diode trio, brush set, capacitor,rectifier, bearings)

Be sure to explain that the alternators are purpose built for an MV, they have Isolated grounds.

I can get them checked out ASAP; but what do the GEN lights mean? Also is it better to just get two new alternators or will rebuilds go a long way. What can I do to check the alternators to make sure that they are working correctly?

typically the gen light is indicating that the alt is not charging, but not always (thier finicky)

As far as the alt stuff, on my truck almost nothing tested correctly with only 1 bad alt...take them and have them tested but remember to tell them to ground the isolated ground for test or it will always appear to be bad(napa wil screw it up everytime)

If drivers side is bad, for less than half the price of the correct unit you can get an alt for an 86 chevy van 100amp model(with large case)that is normally grounded. I got one from a junk yard and it works fine. this I learned from this site.

Rebuilt units are fine, just your own old case.

both alts are same if stock....so they interchange

I'm pretty new here too but just dealt with same stuff GOOD LUCK!

Man I sure do appreciate the help I will get to work today and try to get them tested. I will post later to let you know what I find out.

Will the truck start with an alternator removed totally and not just burned out, as long as the batterys have sufficient charge? Curious if the truck can be moved in an emergency.

That should work for a few starts and run for a while like that. Make sure you secure the wires and remove the belts.

I am going to get it in an hour or so and will let you know how it turns out. I removed the batteries and recharged them over night so I will go at it with good batteries and a demanding attitude at least.

I got to it and hooked the batteries up and it fired right up like new. From the time I started to the time I stopped it the GEN 1 light stayed on bright. The GEN 2 light only came on when I let off of the throttle to slow down and even then it was a flicker. I looked at all of the wiring and best I can tell it is all hooked up right. The battery gauge still reads green. I killed it once home and it had no problem starting back up. After tinkering and checking the wires the GEN 2 light stays on full time. So now both lights are on full-time at at any throttle position. Does anyone have the part numbers for the new alternators and should they be the exact same?

The only source I know of for direct replacements that are new, is ODIron. Even these are not exactly the same item, they are new alternators that have been converted by an alt shop.

The originals are easily rebuilt by a professional shop.

If you don't want your old ones, let me know.

Ill be sure to let you know first if I get new ones. Thanks for the help. How do you post pictures of your rig on the site so others can see it?

Look below this post, there is a quick reply window(you can go advanced also). Use the Manage Attachments button to select(browse) pictures and then upload them to the post.

This is also explained in the FAQ section at the top of the page in the menu bar.
http://www.steelsoldiers.com/faq.php?faq=vb3_reading_posting#faq_vb3_attachments

I got the alternators both tested and GEN 1 alternator was bad the GEN 2 was good. I got a spare off of my 1008 so hopefully that will solve the problem.