Alternator on it's deathbed?

[Cornelius Van]

tl;dr

Lost electrical power on the road. All accessories dead or dying; thankfully the engine kept going. Amp light flickering dimly at best.

Alternator assumed to be cause, as it is original and has 400,000k on it.

After five hours on a charger and 15 minutes on the road, the alternator appeared to be producing a charge again. I am confused.

So I'm driving around tonight and some asshole pulled out a little too far trying leave a parking lot. I had to nudge over a little to make sure I cleared his ignorant ass. I should have just ripped his nose right off, because I could of, but I'm a nice guy and that's not how I roll.

However, I did feel the need to communicate my dismay to this gentlemen, so I hit the horn button.

...Nothing happened.

I hit the other horn button, and this time something did happen. It was quiet. The horn didn't blast at all. It didn't make a sound. But my radio died.

This signalled an alarm bell inside my brain. This alarm bell brought two key memories to my attention.

1. My alternator is the only original assembly on the car and is wearing all of the car's ~400,000 kms.

2. I have noticed the turn signal operates (as in clicks and turns on and off) very slowly at idle over the last few days.

So I tried the horn again. The radio turned off again. I kept it off. I decided that my alternator probably died some time ago and the car's been running off the battery - which is now also on it's last legs.

As the drive went on I started losing more things. My turn signal now did not work. The light would turn on, and stay on - not blink or flash, as an effective signal should.

My clock display went very, very dim. My power window was extremely slow. My headlights went dim too. Very dim, to a point where I could see them on the backs of cars, not off the road.

There was a point, shortly after I lowered the window, where my gas gauge quit. It went went from a three quarter tank to brimming full. My headlights were NOT working at all. I probably lost my brake lights.

Thankfully this only lasted for about a minute. My gas gauge came back to life, and my headlights did too - but I was still clearly operating on minimal power.

Thankfully none of the major components went out. My steering and brakes were fine (hooray for hydraulic assemblies!), and my engine, while down on power, didn't show any signs of imminent death.

When I pulled into my friend's driveway, I noticed the amperage warning light came on - or, flickered. Dimly. Barely.

You know things are bad when the low power light doesn't have any power.

So I assumed my alternator finally bit the dust. Which is a pain in the ass, because it's Easter weekend and I'm gonna have to wait for pretty much anything.

So I hooked up a slow battery charge and left it for 5 or 6 hours. I've since borrowed this charger and a quick boost thing, just in case.

Shortly after I arrived, I had to start the car again to move it up three feet so the charger would reach the battery. It was REALLY slow to start, but it did start - which kinda surprised me.

I checked all the connections I could, everything I could see and check looked fine.

So that just means my alternator's dead and I need a new one, right?

No.

After the drive home I don't know what to think.

So I pulled it off the charger, it fired up okay, and I set off for home. No radio. Minimal dashboard lighting. No smoking (no windows). No fans. Minimal power consumption on my part. I tested the turn signals; they were slow, but they worked. I'm praying there's enough charge in it to sneak me home.

Here's where I get lost.

So about 15 minutes into the trip I try the horn. It beeps.

Then the CHECK ENGINE light comes on.

THEN everything works great. Windows are quick, blinkers blink steadily, even the wipers on maximum attack worked fine. High beams are bright, fog lights are too.

Even at idle.

....what the hell is going on?

[4door]

i had similar promblems. found ground connectoins bad. ran few new cables form frame to variuos body panels ( innerfender,cab)

[jayh]

as said check all your connestions, all your grounds, and especially connections at the starter selenoid
something to think about, the alternator wont work correctly without a good battery

reguardless, I would look into 3g 130amp alernator upgrade, it really is probably the first mod anyone should do, it can be done for $25 at the junkyard

[hemihotrod402]

reguardless, I would look into 3g 130amp alernator upgrade, it really is probably the first mod anyone should do, it can be done for $25 at the junkyard

I was just thinking that when I read the thread. If you aren't too thrilled about using a junkyard alternator, you can find them at a parts store brand new, and they usually come with a lifetime warranty, which means if it goes bad, free alternator!

EDIT: But they are not cheap

[gadget73]

Check all your connections, but the plugs on the side of the alternator are known to get flaky, and the brushes also will wear out in the alternator. Either will cause intermittant charging problems, but so will crudded up battery terminals, grounds, and connections at the starter relay. With 250k miles on it, and if its the original alternator, its more than served it's purpose. Most people don't get half that mileage out of the stock alternators before they fail.

[Lincolnmania]

i would suspect a flaky alt harness and a dying alt.......dont play around with it, the wiring is known to catch on fire

i would do a 3ag conversion

[1990LTD]

that many kms on a stock 2g alternator must be a record of some kind haha

[Cornelius Van]

Update:

1. Thanks for all the responses guys. You rock.

2. I think I've narrowed it down, and potentially found the culprit of last night's failure.

Today, while I was hunting around with my Dad for any bad connections, two things came up:

-There was a plug coming out of the alternator that was *disgusting.* I have never seen so much electrical cheese in my entire life. I didn't think it was the culprit of last nights problem, because there's no way that much garbage could build up over night, but I cleaned it up anyway, because that couldn't be helping things.

-On Monday I took the car into a shop for an oil change. While I was there, I had them throw on some new battery terminals/leads (the connections to the battery, not the battery itself) because my old ones were shot to sh1t.

They did a shoddy job. When they trimmed the negative cable (because it was bad), they went in too deep with the wire strippers and lost a lot of copper in the process. The amount of actual cable hitting the negative terminal was about half of what it should have been.

This could explain why it started to die on me. The thinner power pipe meant the alternator wasn't able to supply a sufficient charge to the battery, and the battery couldn't deal with it anymore - but that would explain why there was still just enough charge to keep the engine turning.

So I fixed that and it seems to be better now. The amperage being delivered still appears to be on the low side, but it's not problematically low and most importantly, it's consistent. I can run with the radio and lights and horn simultaneously and it works.

So a new/rebuilt alternator is definitely in the cards, but its not an absolutely urgent thing like I was worrying it was yesterday.

Might need to look at a battery too. I'll find a multimeter tomorrow and narrow down the health of the battery... or I'll just wait until I get a fresh alternator and see how it behaves.

Either way, situation is under control, and I sincerely appreciate your help guys.

What goes into 3AG swap? It can't be just as simple as dropping a Taurus alternator in, can it?

Also - my friend's father recommended a place that will rebuild an alternator for a very reasonable price. New core, new brushes, repacked bearings... he's been to them before. He said they'd toss in a higher output core if I opted for it... would that work or would it start to cook things?

[87gtVIC]

for the 130amp 3AG upgrade you find the small or large case alternator you need (depends on cars options and engine) then run a 4 gauge charge cable with a mega fuse to the positive battery post or starter solenoid. Chop out the stator wire from the existing three plugged charge cable and plug it into the lone slot on the new alternator. and take the yellow wire our of the voltage regulator and connect it on the alternators charge post.

[gadget73]

Its almost a drop-in. If you can handle replacing battery terminals and changing an alternator, you can swap the thing out.

[1990LTD]

Replacing the alternator took me a 3 hours or so, and it was essentially the first thing I ever had to replace on a car, and I had no mechanical skills whatsoever. I now have very minimal skills

Someone who isn't a fuckup could have it done way quicker than I did.

[91grandmarquis]

Replacing the alternator took me a 3 hours or so, and it was essentially the first thing I ever had to replace on a car, and I had no mechanical skills whatsoever. I now have very minimal skills

Someone who isn't a fuckup could have it done way quicker than I did.

Swapped mine out in 15 minutes. Stock to stock, no upgrade.

[87gtVIC]

I done the upgrade. Took me two and a half hours. I like having everything look like it was stock so everything is well hidden or factory looking.

http://www.grandmarq.net/vb/showpost.php?p=514822&postcount=533

http://www.grandmarq.net/vb/showpost.php?p=515832&postcount=544

http://www.grandmarq.net/vb/showpost.php?p=517691&postcount=552