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ALTERNATOR -going? symptoms please..

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alternator
2K views 17 replies 7 participants last post by  revtor 
#1 ·
So my alternator is starting to emit a high pitch whine at times. I assume this is the bearings going? My question is what really goes bad in an alternator and can these be rebuilt at home? Replace bearings and or diodes , is it difficult? Worth it?

Also what are some common symptoms of an alternator on its way out..?

thanks alot
~Steve
 
#2 ·
Failure to recharge the battery.
Locking up and destroying the belt.
Vehicle shuts itself off because you're draining the battery as you drive.
It gets angry and sneaks over to the passenger side and sabotages the oil cooler lines. (joke)

Rebuilding an alternator is reasonable enough that I personally wouldnt rebuild it at home - plus a shop will give you a guarantee. Most places will put it on the machine and test it for free.
 
#3 ·
If it is just the whine, no other symptoms, I would just press new bearing on/in. Not a hard thing to do, but often you have to unsolder the wire to get full separation of the housing. Again, not hard at all, but some people prefer not to do it theirselves.
 
#4 ·
Yeah, so far its just the whine... Sounds doable if I can order bearings and have them in hand for a weekend job. Soldering, diodes, no problemo..

The reason I ask is because I just got my 90 back from the shop, it was being checked out regarding the random loss of power, stalling, rough idle business.. Its been running great for a week and now today on the highway, same stumbling, loss of power. I have to pull over, shut it down, wait a minute and then it fires up and runs fine again.
Last night while the engine was warm, I almost stalled it pulling up a hill (my bad) out of a parking spot and it wouldn't come out of the low RPM (2-500) stumble, no power.. Had to shut it down and it wouldn't restart, like it was flooded. An hour later it fired.

There is always the smell of fuel, so I'm guessing the ignition system is at fault somewhere, and the tech told me the alternator was going, so Im trying to see if this could be related some how..

would a bad coil be intermittent like this?

so frustrating. I dont mind dealing with rust, getting rained on, the noise etc.. its the charm right? But something that leaves you and your GF stranded for no apparent reason, at totally random times.. will drive me to sell this thing..

~Steve
 
#6 · (Edited)
Background:

The D's been running alot better (past two weeks) since it's been at the shop for mysterious loss of power, rough idle, etc.. found some vacuum issues and a bad coil wire, bad cap.. (New genuine parts bad? yeah, great...)

The alternator's been singing soprano for the past two weeks or so and the fuel pump has been making louder than normal noise for the past few months. I think these items are on their way out (They're both original parts).


Latest:

I drove home last night with no problems, everything seemed hunky dory, replacing the alt and fuel pump were planned for "soon".
This morning my truck wouldn't start. It cranked, and would start/run if I gave it gas, but would hold no idle and wouldn't start unless the acellerator was depressed half way.
My fuel relay clicked on and I heard the pump pumping as normal...(loud)
When the thing shut down the battery light came on.

SO, does this sound like my alternator being done? Sounds more like a fuel pressure issue, which might be caused by low voltage which brings me back to alternator..

any thoughts? Im going to get an alternator ASAP. Anyone have a source for one that will definitely fit? (V-Belts here)

thanks

SNAFU,
~Steve
 
#7 ·
When my coil went bad, the hard starting was a real issue. Did you replace that?

If your lights and wipers work when the engine is on, then chances are the alternator is still generating some power. Otherwise, you would be running the battery down in short order. I'd still replace it, though, as it will fail soon or cause other problems in the interim.
 
#11 ·
Allright, alternator/belt/new bracket ordered..

Ill update this post when its installed.. This issue(s) have been bugging me for a long time, Ill try and summarize what I think I've learned when its all over.

~Steve
 
#12 ·
revtor said:
Ignition control module - do you mean the amplifier? Or is this different, inside the distrib..?
Yup, the amplifier. They're notorious for cooking in their original location on the side of the distributor and can cause similar symptoms to what you're experiencing. They can also be fried by your alternator going south (both have happened to me). I wouldn't be surprised if you have both issues at work.
 
#13 ·
Is there a known way to check if the amplifier is good/fried?

Follow-up Post:

Well I just spent an hour looking around for anything unusual, everything looked fine.. started the truck, won't idle at all.. So I adjusted the base idle screw and now eveything seems fine again.. What could change overnight that would necessitate me taking two turns out ont he idle screw?

aaah!
~Steve

running....wrongly
 
#14 ·
The workshop manual has a remarkably good test procedure to diagnose ignition problems, it's worth taking the time to break out your multimeter and go through it. Rover's "fix" for the issue was a remote module kit STC-1856. A quick look around revealed that the price has frigging skyrocketed. If the module does turn out to be the culprit, you may want to ping PT or Pendy to see what they came up with for rigging a ford ICM -- I think they were both playing with that ca. 18 months or so ago.
 
#15 ·
Thanks for the help Tony..
Yeah I saw $518 for the amp relocation kit.. ouch. I'll solder up my own extension wire if that's the cost. Don't think the amp has been relocated on my truck, the only thing out by my coil is a little silver metal cylinder with one wire coming from it..? the amplifier Ive seen in the catalogs is a black rectangular job with 2 or 3 wires...

I ran the high beams and the heater at full blast for a while and my voltages stayed fine, so for the time being my alternator is putting out OK voltage..

Id break out the multimeter, but unfortunately my manual doesn't cover the fuelinjected V8. I need to get the right friggin manual......

~Steve
 
#16 ·
"Well I just spent an hour looking around for anything unusual, everything looked fine.. started the truck, won't idle at all.. So I adjusted the base idle screw and now eveything seems fine again.. What could change overnight that would necessitate me taking two turns out ont he idle screw?"

Stuck stepper motor. Computer out of spec needing to be reset (it resets itself) because you have been running with a bad alternator.
 
#17 ·
Steve,

Check your ignition coil. One sign of bad distributor amplier module is that it fries the coil.

When mine went, the coil was extremely hot - too hot to touch - and it was extruding a black tar-like substance from its innards.

I replaced my whole system with Mallory. (Note I have a different issue now per my Thread D-110 Died -Your Thoughts?)

Good luck,
 
#18 ·
Dennis, thanks for that tip.. I actually did feel the coil, but it wasn't that hot. I'm going to double check my stepper motor, see if that clears up my weird idle issue... For now its running though.

Yeah I saw your checklist, nice post - should be a page in everyone's owners manual!

~Steve
 
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