So here we go...
I have tired myself for the past 3+ days trying to figure out the problem. First, let me start off by saying that I just recently (last week) tore my whole dash apart and did all that happy stuff evolving a new heater core, so if that info helps...here we go.

My car died just recently and I thought I just exhausted the battery on the car trying to fix and tune some stereo and miscellaneous parts on the car. I figured it would be a good investment to by a good battery, so I did. After the new battery installation, I ran the car for a while to see if everything was ok. It wasn't, my battery gage was around 12 volts and testing the battery with a volt-meter, it was running at about 11.5, and the gage wouldn’t really move at all when running the car. I thought it was a bad connection with the wires behind the instrument panel. I tore the IP apart again and checked the connection, which was good. So then I thought it was my alternator. I took my old one off and inspected it, and it caught when it was spun freely in a small spot. I thought what the hell, I should get a good alternator for the car too, so I bought a new one (which I kind-of regret now cause the old one tested fine). Hooked the new one up and still the same results as before. So then I went and tested all the connections on the alternator, battery, coil, and found nothing out of the ordinary. I also tested all the battery cables, wires to and from battery and alternator. I replaced the pigtail coming off the alternator thinking corrosion was the cause of the bad voltage, and still, the same results.
I am running out of ideas...and help would be greatly appreciated!!

 

Am wondering if the cable ends have any copper exposed that might be allowing the growth of the green fuzzy acid type stuff that acts like a bull dog on a garden when u were a kid playing with the water hose Yes some juice or water gets threw but not enough to turn the starter

I did the same as you in a quest to get a car to start once. I replaced battery, and starter only to find i should have done the cables first

PS I peeled back the rubber surrounding my cables for over a foot before the GREEN FUZZ stopped

Another thought would be to do a draw test at say AutoZone It should not be drawing more than .04 at any time with engine off and everything else off as well If if does? Be ready to yank fuse's from fuse box to determine whats the culprit (Direct Short some where}

 

+1, corrosion will definitely cause weird problems

 

I would see if anything is drawing power from the battery when your car is off...that could be it.

 

ok...i replaced both cables and checked the one from the starter to the relay...all good and yes...it helped....to a point...

the car sits around 13.5ish if not a little higher/lower.....starts, and dips like it should when it cranks...

when its running though, it creeps up reeeeally slow, and once it gets back to about 13.6ish voltage, that is where it sits.

granted i know that is OK...but i dont like it bein OK. I would like to fix the charging problem so i know it is reliable.

tested the new altenator and it is fine as well (brand new battery too)

 

I would check around and see if you can find someone who is good with automotive electronics...two town over from where I live there is a guy in his late fifties who is an expert at all electrical stuff on cars...he has worked on my current Mustang as well as previous...he knows his stuff and can usually tell within half a day when it comes to stuff like that. The best part is he is fast, and doesn't charge alot. Plus, he is a one man operation and I never hesitate to give him the work because it doesn't hurt to help the little guy in the large scope of things.

I have had problems like this, where after this guy looking at it for an hour he figures it out.

 

anywhere close to wisconsin? lol

 

haha, unfortunately not, I'm up in the North East in Rhode Island!

 

are there any grounds/wires under the dash that would stop the charging system from working properly?

 

the car drains after a couple of days of sitting too

 

there are so many variables that it is too hard to tell...my knowledge of automotive electronics is slightly above novice...your best bet is to have it looked at, or unhook the terminals from the battery cables every time you turn the car off...

 

when the flashers are on my battery gage goes up and down with every click of the lights if that helps at all...i've tried pullin fuses to locate the draw and it didnt help

...and it never did it before the heater core transplant...it would run in the 14's-15's

 

there's a short somewhere in your system...it could be easy to find, or it could be like a bad game of 'where's waldo'

 

sorry for the quality of the pics...all i have is my phone for pictures....


i was wondering what these two wires were on the left side of the steering column behind the dash...they are black with a white tracer

http://c2.ac-images.myspacecdn.com/i...ec66c5f3f1.jpg

http://c3.ac-images.myspacecdn.com/i...a0a0914df6.jpg

http://c3.ac-images.myspacecdn.com/i...a7844af942.jpg


i also was wondering if anyone knew what this was? it is behind where the radio would be and i am thinking of a slight chance antifreeze leaked into/onto it?

http://c1.ac-images.myspacecdn.com/i...5120ba67e4ce98

http://c2.ac-images.myspacecdn.com/i...dbf5e1ac71.jpg

http://c2.ac-images.myspacecdn.com/i...83bc3fd471.jpg

http://c4.ac-images.myspacecdn.com/i...ed42cb2183.jpg

 

well, there could be a coolant leak from the lines that go to your heater core. If those lines are leaking, they'll likely leak on such electrical wires.

 

That is the factory amp for for the stereo.

 

i have not fixed it yet...i am looking at everythign again...grounds seem ok and clean...dash is out again and no bad wires or anything, no metal/wire connections causing shorts, altenator is fine, battery fine, all wires at coil stuff tested fine, fusable links tested fine, checked all fuses...fine...i just cant figure the darn thing out!

 

also adding that now that i have changed the battery in my multimeter (it was reading voltage like crap cause of bad/dieing battery) the car runs around 11.85ish to 12.40ish volts...low end with lights on and high end with no load what-so-ever

 

I know you've mentioned that you had the alternator tested, but have you thought about maybe getting a 2nd opinion from another parts store?

 

i have had it tested at multiple stores....all tested good