Alternator Problems HELP!!!!

Cub61 · #1 10-16-2009, 09:21 PM

Hey how's it going everyone!!!!!

Guys, my Dad and I need your help. I'm helping my Dad work on his 1988 Chevy 1/2 ton Silverado Suburban. Let me explain the problem that we are having with this Suburban.

My Dad had to take my Mom to work this past Monday due to dense fog that early morning. And coming home after dropping my Mom at work the Suburban starting to loose power from the battery. The way my dad explained it to me, is that he started to notice the Head Lights dimming out and the windshield wipers were also starting to slow down in movement. He also noticed the Amp Gauge was dropping amps very rapidly and it continued to do so until the engine of the Suburban just stalled out on him. So he steered it to the side of the road. He tried to fire it back up but the battery was completely drained out. The battery barely had enough power to power up the Emergency Lights. So he called me that morning telling me where he was at and what had happened. So I took off to go tow him back to the house. So, we've been working on this problem for the past 5 days now and we still can't find the problem. We first went after the battery thinking it was the battery that caused the problem. So we replaced the battery with a new one and noticed the Amp Gauge was still dropping Amps as the engine was on. So we replaced the Alternator with a brand new one thinking that was the problem. And after we replaced the Alternator we're still NOT getting any Amp Charge from the Alternator. The only thing the engine is doing is living off the Amps that the battery has in it and NOT replacing the Amps back into the battery with the Alternator. The new Alternator is acting like a DEAD Alternator. We have checked just about every wire and every fuse on this Suburban and we still can't find the problem. So if you guys have any ideas,suggestions,tricks, whatever. Don't hesitate to tell me. We could really use all the help we can get. Hope to hear from you guys and thank you very much for your time. Take care everyone!!!!

MATT

RPalmer · #2 10-16-2009, 10:07 PM

Cub61,
I had a very similar problem under very similar conditions. Really. What it wound up being was corrosion at the positive side where a side mount cable was cut and a new end placed on it. And at both ends of the negative cable.

I was glad to have it fixed. I had to do it in the rain. But I was honked-off too because last year I had a new battery installed. There was no way that much corrosion developed in a year. So the good people who charged me $110.00 for a battery never cleaned the cables.

I felt like going back there and asking them if cleaning and tightening terminal cables was extra. Don't assume someone who should have done something did it. Good luck with your search.

Rhoderman · #3 10-17-2009, 01:07 PM

Hey there Matt!
Sorry to hear about your dad's problems.
Like Mr. Palmer says, first check all your connections.
I'd guess his battery connection is fine since a new battery starts it and operates the lights.

Ah, found me book! Chilton's 88-93 Chevy Truck Repair Manual. Page 6-63. It shows a red wire from the starter to the big stud on the back of the alternator. It shows a fusible link, blue in color, next to the starter.
Chances are, he smoked that fusible link. This may have occurred for any reason, but the most likely is the old alternator tried to overcharge the battery and took it out. Another possibility is that it shorted out on the exhaust manifold.
A fusible link is simply a smaller piece of wire for a short distance so it fries that one section instead of killing the whole harness. I believe you can buy them from autoparts stores, if not, go to Chevrolet garage and buy one.

Sometimes you can tell a dead fusible link because it's toast. Other times, you can pull on it and try to stretch it. If it stretches the insulation the wire inside is no longer a piece of wire.

In the future, if the truck is running and the battery discharges, it probably isn't the battery. Battery problems pretty much always show up when you try to restart it the next time. Just trying to save you the cost of a battery next time...

Good Luck Matt, and let us know what you find!

Jim

Cub61 · #4 10-17-2009, 05:27 PM

Hey how's it going guys!!!!

Thanks guys for the help and suggestions. My Dad and I really do appreciate it. We'll definitely check today into the Cables and also the fuseable links and see if we can't get that Alternator to fire up and start charging up the Battery. By the way guys, I forgot to mention that the Suburban is also draining out the Battery whether the engine is on or off. Which is a problem that we have NEVER had with this Suburban, until now. Any ideas what could be causing this to happen???? Could this also be a problem within a bad fuesable link???? Thanks guys!!!!

MATT

Rhoderman · #5 10-17-2009, 07:12 PM

Fusible link is not likely the reason for a battery drain.
However, bad diodes in the alternator could cause that.
Does the new alternator drain the battery too?

Cub61 · #6 10-17-2009, 08:13 PM

Quote:

Originally Posted by Rhoderman

Does the new alternator drain the battery too?

Hey Jim!!!! How's it going good buddy!!!!

Yes sir, the new Alternator is also draining the Battery. Like I said before, it also drains the battery out when the engine is off. So as of right now we are having to remove both battery cables off the battery. If we don't remove both battery cables we end up with a dead battery by morning.

Let me give you an example on what we are experiencing:

We put on a fresh battery,then we fire up the engine. (Keep in mind that we have a brand new Alternator already installed.) The Amp gauge by this time is reading a little less than 13 amps. Next,we put a full load on the Alternator meaning by turning on the Head lights/Parking Lights,Console lights,Windshield Wipers,Radio,Heater Blower,Dome Light, and just about everything else that runs off the Battery. And by this time, the Amp Gauge is slowly moving towards the Red Zone of the gauge. Meaning that we are loosing Amps from the battery and nothing is coming in from the Alternator to replace those Amps back into the battery. What do you think????

MATT

Rhoderman · #7 10-17-2009, 10:08 PM

Hi Matt!!! Sorry you haven't fixed it yet. It should be real easy.

#1, you don't have an Amp-meter (ammeter), you have a VOLT-meter. Amps is flow, and Volts is pressure. The gauge in your dash is showing you the VOLTs on your battery.

If your voltage (VOLTage) is dropping, your alternator isn't charging.

When you start, 13V is a good indicator that you have a fully charged battery. They are 12V at almost dead. 12.5 to 13 is usual for a full battery.

When your alternator is running, you should see 14V or more on the VOLTmeter in the dash. If not, your alternator, or the connection from it, is bad.

If you have a bad alternator, it won't be the first time I've seen a dead one out of the box. Just because it's new don't mean it's good. Really... Sometimes people return a dead one and say they didn't install it. We see that around here.

If you're within a few miles of your auto parts store, take the alternator to them and have it checked.

Your alternator isn't discharging the battery. It simply isn't RE-charging it. Your heater fan motor draws a ton of current. That'll bring her down fast. Right now, all your alternator is doing is giving the belt a place to run.

If your alternator checks out, your fusible link is GONE, toast, fried, dead. If the alternator is good, and spinning fast enough, it's creating about 14V or more on the output. If that output is connected via a wire to the battery, it WILL charge the battery. If the wire is either open or damaged, it won't be able to charge the battery.

If you have a voltmeter, measure the V at the alternator output lug. When running, it should be +14V or more. When not running, it should be the same Voltage as your battery since it is all the same circuit. If you measure 0V on that lug/stud, your fusible link is wide open, burned out.

Hope this helps!

Jim

Cub61 · #8 10-18-2009, 12:27 AM

Hey Jim!!! How's it going good buddy!!!

I really do appreciate your time and help.

As for the Alternator, it's the second brand new Alternator that we have purchased since this problem started. We purchased a brand new Alternator this past Monday and that Alternator didn't work. So we took it back the next day(Tuesday) and got another brand new Alternator(which is the one that is currently installed onto the engine) and that Alternator isn't charging either. We're checking into the Fuseable Links as of right now. We located one that's very near to the Starter and ran a test light and the light fired up. So we have fire there. We're still trying to locate that Blue wire that you mentioned, but having a little trouble removing the protective covers off of them so we can see the colors of the wires. But we're getting there. By the way Jim, this truck was pushing 14 volts before all this happened. But like I said before, now we're only getting less than 13 volts, and that's even when the engine is on. So it's like you said, we're not getting any power from the new Alternator. I'm guessing we might have to take this second new Alternator back and get another new one.

One more thing Jim, any explanation why the battery is discharging itself while the ignition is in the off position???? I've heard that a bad starter solenoid will cause a battery to discharge itself. Apparently a bad starter solenoid will continue to draw power out from the battery. Not enough to make the starter come alive, but just enough to drain your battery. Is that true???

Let me tell you something Jim, I've been a mechanic for quit some time now. And I really do enjoy it. But this electrical stuff just plain and simply drives me nuts!!!! LOL Put me to rebuild a carburetor for you or install a water pump, anything. But just don't put me to do the electrical part of the engine.LOL This Suburban has got me STUMPED!!!!lol

MATT

michcruiser60 · #9 10-18-2009, 07:19 PM

Hey Matt,

When I'm stuck with a problem on my Chevy, I'll look go to this website..

http://www.chevytalk.org/fusionbb/index.php?

You can do a search for your problem. I'm sure you can find the answer there.

Mich60

Cub61 · #10 10-19-2009, 12:02 AM

Hey Mich60!!!! How's it going good buddy!!!!

Thank you very much for the link!!!! I really do appreciate it and it helped a lot too!!!! Found exactly what I was looking for.

Well guys, we finally found the problem.The 2 wire clip that goes into the side of the alternator is our problem. There are two wires just like I stated. One wire is a reddish color and the other wire is a brown wire. Now, from my understanding both wires should have fire going through them once the Key is turned to the "On" position. We checked it out with a light tester, and we only have fire going through the Reddish wire and NOT the Brown wire. Does anyone know where the Brown Wire leads to???? Does it come out straight from the Alternator to the Fuse Box or the Ignition???

MATT