Fox T-Bird/Cougar Forums

Technical => Electrical Tech => Topic started by: nutwagon on October 22, 2007, 07:11:29 PM

Title: Alternator coil question
Post by: nutwagon on October 22, 2007, 07:11:29 PM
I found I have a bad alt since its been sitting for almost 3 years in the garage. what usually goes bad on an alt from sitting? the coil brushes or something else? I see they cost 150 bux for a whole new alt and thats too much money for me. I found a coil off ebay for possibly 10 bux.
Title: Alternator coil question
Post by: softtouch on October 23, 2007, 03:04:37 PM
How are you testing the alternator to know it is bad?
Does it have an internal regulator?
Can you post the link to e-bay so we can see what "coil" you are talking about?
Title: Alternator coil question
Post by: Thunder Chicken on October 23, 2007, 04:49:14 PM
If the car's been sitting there are a few things that could go wrong with the alternator. Most common would be bearings seizing up and brushes sticking in their holders, but you can also run into moisture getting into the windings, causing them to expand, which breaks the insulation and causes shorts. Since yours has been sitting in a garage this is unlikely. I'd check the brushes.
Title: Alternator coil question
Post by: nutwagon on October 23, 2007, 08:43:13 PM
I think it has to be the alt because I`m getting suck a weak spark and I have gone through the whole ignition system except the coil but I ran a spark tester on the coil and got a strong spark from it. everytime I hook the tester to the distributor I get a really dim spark. The alt pulley came off before and it wouldnt pull enough power through and shows the same signs.
Title: Alternator coil question
Post by: Thunder Chicken on October 23, 2007, 08:51:07 PM
If there's enough juice in the battery to spin the starter, there's enough juice to fire up the coil. Hell, I had an alternator fail in my old '85 and tried to drive it home anyway - home was 100 miles away and it was dark and raining. I had given up on headlights and wipers (thankfully the rain stopped), and was following another car. It got to the point that there wasn't even enough juice in the battery to power the digital dash or clock, but the engine kept running.  I made it about 75 miles. I would have made it even further but I got pulled over by the police for driving without my headlights off, and the cop told me to shut the car off. As soon as I did I knew it wouldn't start again...
Title: Alternator coil question
Post by: nutwagon on October 23, 2007, 09:39:50 PM
see it ran last spring and almost started like a week ago and it was trying to start but wouldnt do nothing now.
Title: Alternator coil question
Post by: softtouch on October 23, 2007, 09:44:39 PM
Does the car start?
Title: Alternator coil question
Post by: softtouch on October 23, 2007, 09:47:25 PM
You answered my question before I could ask it.

The alternator doesn't do anything until the engine is running.
Title: Alternator coil question
Post by: softtouch on October 23, 2007, 10:08:06 PM
Pull the codes.
Check the fuel pressure.
How does the spark look while cranking?

I am not familiar with the spark tester. How does it work?
Title: Alternator coil question
Post by: jcassity on October 24, 2007, 01:05:13 AM
the spark testers just plug in to the plug wire and gator clip to ground.  They substituted for a spark plug in a way.

im not really sure what this problem is here but a weak spark should be dizzy related with the tfi or the pick up/stator assembly.
Title: Alternator coil question
Post by: nutwagon on October 24, 2007, 01:51:48 AM
whats a pick up strator assembly? or a tfi? Is the pick up the orange looking thing inside the distributor? every time I check the obd codes it says cyl 1 and 6 problem.
Title: Alternator coil question
Post by: softtouch on October 24, 2007, 10:55:50 AM
What year and engine do we have here? Is it stock?
Title: Alternator coil question
Post by: nutwagon on October 24, 2007, 01:00:34 PM
Its an 88 5.0 from a thunderbird sport. No matter what I do I get a weak spark. Its pretty much all stock.
Title: Alternator coil question
Post by: nutwagon on October 24, 2007, 08:29:30 PM
It looks like worn out brushes in the alt
Title: Alternator coil question
Post by: Chuck W on October 24, 2007, 08:45:19 PM
Are you not listening??  The alternator has [COLOR="Red"]NOTHING [/COLOR]to do with the car starting or not starting.

How about checking your battery cables?
Title: Alternator coil question
Post by: TurboCoupe50 on October 24, 2007, 09:44:10 PM
Quote from: Chuck W;184447
Are you not listening??  The alternator has [COLOR="Red"]NOTHING [/COLOR]to do with the car starting or not starting.

How about checking your battery cables?


X2...

You can pull the Alt and toss it into the street, it will still start...
Title: Alternator coil question
Post by: nutwagon on October 25, 2007, 02:37:59 PM
Ya I heard but the alt is no good though. The cables look fine.
Title: Alternator coil question
Post by: Chuck W on October 25, 2007, 03:27:50 PM
Quote from: nutwagon;184568
Ya I heard but the alt is no good though. The cables look fine.



They can look fine but be bad.

Replace the cables.

As mentioned now 3-4 times...the alternator has nothing to do with the car starting.  You'll put a new one on there and it still won't start.
Title: Alternator coil question
Post by: Beau on October 25, 2007, 06:21:26 PM
battery cables clean?
tight?
corrosion free?
is the battery good?
starter tight?
is the starter any good?
all these things WILL keep car from starting
all the ALT does is keep battery charged up...
I've had a case where the voltage regulaton inside the ALT on a 5.0 went bad, draining the battery, but that's neither here nor there...

ALt should be the last worry in a no-start case like this
My thought is a bad cable/ground or the like, either loose, or dirty.
Title: Alternator coil question
Post by: nutwagon on October 25, 2007, 07:33:41 PM
battery is new, the starter is a year old and cranks, cables are tight and corrosion free. I need to double check the grounds maybve something broke off.
Title: Alternator coil question
Post by: Beau on October 25, 2007, 08:55:34 PM
Quote from: nutwagon;184191
I have gone through the whole ignition system except the coil...

i think you nailed it with that. try that and see what happens.
Title: Alternator coil question
Post by: Kitz Kat on October 26, 2007, 03:58:43 PM
Quote from: nutwagon;184345
Its an 88 5.0 from a thunderbird sport. No matter what I do I get a weak spark. Its pretty much all stock.

What does this have to do about a alternator?
Title: Alternator coil question
Post by: nutwagon on November 01, 2007, 04:30:32 PM
the alt was bad and needed new brushes, along with a corroded cap and rotor and bad plugs