Charging System

Doctor DeBo · 02-06-2003, 05:05 PM

Ive got an on going problem with my charging sytem that I need some opinions on.I had an electrical fire over a year ago and ended up replacing all the wire harnesses,batt,alt,and ignition switch,every thing electrical has been replaced except for the EEC.The story is when I start the car the batt. voltage(with my fluke meter connected to the batt.)is 12v,it slowly climbs to 13v+ after about 10 min.Turn on the head lights on and it slowly heads back down to -12v.Ive had the alt bench checked and it charges to 14v,Ive checked all the fuse links and they're good.I run an Aeromotive fuel system with the external pump and wonder if thats what is creating the problem,or possibly the alt is bad regardless of the good bench test.The alt is a 95amp,Ive got a 130amp off to the side but want get this damn thing figured out before putting it in,dont want a repeat of the fire a year ago.Sorry this is so long but I thought I would give as much info as possible.Your thoughts will be appreciated.

mustangII460 · 02-06-2003, 08:46 PM

I don't understand what your problem is?

The voltage sounds right. The alt comes on when the battery reaches 11volt or so. It charging up to 14 volts is good. What kind of amps is it turning. It can have all the volts but if it don't have enough amps, the battery won't cut the mustard..

Your car not starting or something?

Doctor DeBo · 02-06-2003, 10:14 PM

The car starts fine.The alt should charge immediately,it shouldnt take ten minutes to get to 13v.The load of head lights shouldnt have that big of a draw to pull down past 12v.The charge gauge reads the same as the volt meter while its running.The battery is a new Optime red top and reads 12.49v with the ignition off.I got the alt from Advanced so it may be the problem.I might just swap in the 130amp alt for trouble shooting purposes.The only time I saw 14v was when it was bench checked.

Doctor DeBo · 02-06-2003, 10:16 PM

I didnt check the amps yet,do it tomarrow.

mustangII460 · 02-06-2003, 10:35 PM

Anyway, It should only charge when the battery reaches 11volts or so. Im not sure its suppose to start charging when its first started up. If the battery is not low, I don't think it should.

Ive seen alt's take various times to reach higher volts. When the lights are turned on, or there is another drain, like A/C. The voltage should start to climb. But if its taking 10 minutes for the voltage to reach 13/14, somethings bad. If its going only to 13 volts, its bad.

Again the alt should only kick on when voltage is low. Your car runs off the battery, untill a certain point. Then the alt recharges the battery for your car to run it down again, over and over.

Now I confused myself.

Maybe one of us understands this now

Doctor DeBo · 02-06-2003, 11:03 PM

Yes,its a big pain.Like you said though somthing isnt right,Ill try another alt and see what happens.Thanks for the replies.If I figure it out Ill post the results.

jimmyjamed · 02-08-2003, 06:17 PM

The alternator is (should be) trying to keep the voltage at ~13.5, and it should be doing this almost instantly after startup, maybe a second or two.

Depending on what voltage the batt is and the loads(lights, stereo etc) will determine how much current is going to be flowing.

The alternator doesn't let the batt go down to 11 volts before it starts charging. It puts out a constant voltage, varying very slightly, unless its loaded down hard or not spinning fast enough. Your battery would be fried in short order if it were run down, charged up, run down, charged up all the time.

It sounds to me the the alt is bad. It may be able to put out 14 volts, but when it gets loaded down it can't hang and the voltage drops. I don't know if the tester the store is using loads the alternator or just spins it up and measures the voltage.

Put in the 130 amp. I did and it made a big difference. Now the voltage doesn't drop at idle with the underdrive pullies!

Also, unless you have a clamp-on ammeter for that fluke, don't try to measure the current. Your meter will only measure 10 amps max, more than likely, and your alternator (if it was good) has the capability to put out ~60 amps. I don't think the 10 amp scale on your meter is fused, so something is gonna burn if theres much more than 10 amps flowing.

Doctor DeBo · 02-09-2003, 12:05 AM

Thanks for the input jimmy,its funny you brought up the clamp on ampmeter as I just aquired one today for my Fluke.I changed the alt and it was no help,same result.Im now looking at the Aeromotive fuel pump as a possible cause,that and the EEC are the only things electrical in the car that were there during the fire.That and the 10 gauge wire that goes from the pump relay to the battery has a splice in it and the splice may have too much resistance so Ill run a new wire.I hope its not the pump,they're not cheap. Thanks again.

jimmyjamed · 02-09-2003, 08:49 AM

I'm sure you checked it, but i've seen it cause problems before... is the belt tight? Sometimes with underdrive pullies, bypassing a smog pump, etc.. belt configurations and lengths can change causing the tensioner being too tight or too loose.

I don't see the EEC or the pump causing charging problems, unless the pump is bad pulling WAY to much current to run, but thats stretching it. If the pump feed has a high resistance splice, it should just degrade the voltage going to the pump, not cause charging problems, unless it is shorting to the frame slightly but not enough to blow a fuse.

Did you put another advanced auto alternator in it? I've heard of people getitng bad parts from them several times then going somewhere else and problem is solved. Also, it seems, to me anyway, that the quality of advance's part has gone seriously downhill in the past year or two. I guess their trying to keep profits up without charging much more. When I put the 3G alternator in my car, I went there to get a rebuilt one. That thing looked rough! The Casing was even bent up. Then I got one from autozone that looked brand new.

How much was the clamp-on? Does it do DC amps too? I've been wanting to get one fo those for my fluke 89, but the ones that do ac and dc amps ain't cheap!

tommyinla · 02-09-2003, 10:03 PM

you might have a bad battery... it could show as charging but the battery could still have a dead cell. i've never seen a system take that long to get to a charging level (should be immediate), but a battery problem would make sense here...

Doctor DeBo · 02-09-2003, 11:05 PM

I got the amp clamp off a friend,its made by Extech and it does both AC/DC amps.Your right about the ones from Fluke being expensive Jimmy.No I didnt go back to Advanced for the alt,I whent to Ford.The belt is tight and Im not running under drive pulleys.the supercharger set up has the alt at the bottom right under the smog pump but it charged fine before my electrical fire.The battery is a new Optima red top,I did buy it from advanced so who knows.Im off work Thurs/Fri so Ill get back into it then.Thanks for all the input guys,Im anxious to find out what the hell is wrong,its starting to get expensive.

gtsr515 · 02-10-2003, 12:02 AM

sounds like a missing or faulty ground????

Jay

Doctor DeBo · 02-14-2003, 07:51 PM

Well I figured out my charging problem and it can be blamed on stupidity.I had removed my A/C way back when I started modifying my car,after my electrical fire I removed my power steering pump and went with a manual rack,this left no pulleys on the left side of the eng.To make this set up work I re-routed my serpentine belt,instead of the belt coming off the alt and up to the water pump it went over to the crank pulley first.Big mistake as the belt made less contact with the alt pulley.So I ordered up a smog elliminator pulley and mounted it on a bracket fabricated from 3/8 steel,put it on the left side of the engine and routed the belt the way the damn thing was supposed to go.I now have 14+ volts.It took me two days to make the bracket and set it up.Its funny how complicated things get when you over look the obvious.

02-06-2003, 05:05 PM	#1
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	Charging System Ive got an on going problem with my charging sytem that I need some opinions on.I had an electrical fire over a year ago and ended up replacing all the wire harnesses,batt,alt,and ignition switch,every thing electrical has been replaced except for the EEC.The story is when I start the car the batt. voltage(with my fluke meter connected to the batt.)is 12v,it slowly climbs to 13v+ after about 10 min.Turn on the head lights on and it slowly heads back down to -12v.Ive had the alt bench checked and it charges to 14v,Ive checked all the fuse links and they're good.I run an Aeromotive fuel system with the external pump and wonder if thats what is creating the problem,or possibly the alt is bad regardless of the good bench test.The alt is a 95amp,Ive got a 130amp off to the side but want get this damn thing figured out before putting it in,dont want a repeat of the fire a year ago.Sorry this is so long but I thought I would give as much info as possible.Your thoughts will be appreciated. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-06-2003, 08:46 PM	#2
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	I don't understand what your problem is? The voltage sounds right. The alt comes on when the battery reaches 11volt or so. It charging up to 14 volts is good. What kind of amps is it turning. It can have all the volts but if it don't have enough amps, the battery won't cut the mustard.. Your car not starting or something? __________________ Frank

02-06-2003, 10:14 PM	#3
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	The car starts fine.The alt should charge immediately,it shouldnt take ten minutes to get to 13v.The load of head lights shouldnt have that big of a draw to pull down past 12v.The charge gauge reads the same as the volt meter while its running.The battery is a new Optime red top and reads 12.49v with the ignition off.I got the alt from Advanced so it may be the problem.I might just swap in the 130amp alt for trouble shooting purposes.The only time I saw 14v was when it was bench checked. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-06-2003, 10:16 PM	#4
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	I didnt check the amps yet,do it tomarrow. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-06-2003, 10:35 PM	#5
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	Anyway, It should only charge when the battery reaches 11volts or so. Im not sure its suppose to start charging when its first started up. If the battery is not low, I don't think it should. Ive seen alt's take various times to reach higher volts. When the lights are turned on, or there is another drain, like A/C. The voltage should start to climb. But if its taking 10 minutes for the voltage to reach 13/14, somethings bad. If its going only to 13 volts, its bad. Again the alt should only kick on when voltage is low. Your car runs off the battery, untill a certain point. Then the alt recharges the battery for your car to run it down again, over and over. Now I confused myself. Maybe one of us understands this now __________________ Frank

02-06-2003, 11:03 PM	#6
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	Yes,its a big pain.Like you said though somthing isnt right,Ill try another alt and see what happens.Thanks for the replies.If I figure it out Ill post the results. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-08-2003, 06:17 PM	#7
jimmyjamed Registered Member Join Date: May 2000 Location: Wilmington NC Posts: 47	The alternator is (should be) trying to keep the voltage at ~13.5, and it should be doing this almost instantly after startup, maybe a second or two. Depending on what voltage the batt is and the loads(lights, stereo etc) will determine how much current is going to be flowing. The alternator doesn't let the batt go down to 11 volts before it starts charging. It puts out a constant voltage, varying very slightly, unless its loaded down hard or not spinning fast enough. Your battery would be fried in short order if it were run down, charged up, run down, charged up all the time. It sounds to me the the alt is bad. It may be able to put out 14 volts, but when it gets loaded down it can't hang and the voltage drops. I don't know if the tester the store is using loads the alternator or just spins it up and measures the voltage. Put in the 130 amp. I did and it made a big difference. Now the voltage doesn't drop at idle with the underdrive pullies! Also, unless you have a clamp-on ammeter for that fluke, don't try to measure the current. Your meter will only measure 10 amps max, more than likely, and your alternator (if it was good) has the capability to put out ~60 amps. I don't think the 10 amp scale on your meter is fused, so something is gonna burn if theres much more than 10 amps flowing. Last edited by jimmyjamed; 02-08-2003 at 06:26 PM..

02-09-2003, 12:05 AM	#8
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	Thanks for the input jimmy,its funny you brought up the clamp on ampmeter as I just aquired one today for my Fluke.I changed the alt and it was no help,same result.Im now looking at the Aeromotive fuel pump as a possible cause,that and the EEC are the only things electrical in the car that were there during the fire.That and the 10 gauge wire that goes from the pump relay to the battery has a splice in it and the splice may have too much resistance so Ill run a new wire.I hope its not the pump,they're not cheap. Thanks again. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-09-2003, 08:49 AM	#9
jimmyjamed Registered Member Join Date: May 2000 Location: Wilmington NC Posts: 47	I'm sure you checked it, but i've seen it cause problems before... is the belt tight? Sometimes with underdrive pullies, bypassing a smog pump, etc.. belt configurations and lengths can change causing the tensioner being too tight or too loose. I don't see the EEC or the pump causing charging problems, unless the pump is bad pulling WAY to much current to run, but thats stretching it. If the pump feed has a high resistance splice, it should just degrade the voltage going to the pump, not cause charging problems, unless it is shorting to the frame slightly but not enough to blow a fuse. Did you put another advanced auto alternator in it? I've heard of people getitng bad parts from them several times then going somewhere else and problem is solved. Also, it seems, to me anyway, that the quality of advance's part has gone seriously downhill in the past year or two. I guess their trying to keep profits up without charging much more. When I put the 3G alternator in my car, I went there to get a rebuilt one. That thing looked rough! The Casing was even bent up. Then I got one from autozone that looked brand new. How much was the clamp-on? Does it do DC amps too? I've been wanting to get one fo those for my fluke 89, but the ones that do ac and dc amps ain't cheap! __________________ '65 Mustang vert, 289 4V, 4 speed '93 LX Ported E7's, Ported Cobra intake, 73mm MAF, 65mm Throttle Body, 1 5/8" shorty's, Underdrive Pullies, 3.55's, 5 speed snatched by a PRO 5.0 shifter, 155,000 and still screamin'! Last edited by jimmyjamed; 02-09-2003 at 09:06 AM..

02-09-2003, 10:03 PM	#10
tommyinla Registered Member Join Date: May 1999 Location: Ocala, Florida Posts: 219	you might have a bad battery... it could show as charging but the battery could still have a dead cell. i've never seen a system take that long to get to a charging level (should be immediate), but a battery problem would make sense here... __________________ 85GT Convertible soon to be sold... 67 Mustang 289. Holley Red electric fuel pump, 4 speed toploader, dual exhaust, torq thrust IIs (real soon!)

02-09-2003, 11:05 PM	#11
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	I got the amp clamp off a friend,its made by Extech and it does both AC/DC amps.Your right about the ones from Fluke being expensive Jimmy.No I didnt go back to Advanced for the alt,I whent to Ford.The belt is tight and Im not running under drive pulleys.the supercharger set up has the alt at the bottom right under the smog pump but it charged fine before my electrical fire.The battery is a new Optima red top,I did buy it from advanced so who knows.Im off work Thurs/Fri so Ill get back into it then.Thanks for all the input guys,Im anxious to find out what the hell is wrong,its starting to get expensive. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

02-10-2003, 12:02 AM	#12
gtsr515 Registered Member Join Date: Nov 2001 Location: Sunny, Hot, Sebring, Florida Posts: 725	Ground sounds like a missing or faulty ground???? Jay __________________ Remember...2nd place is 1st place for losers!

02-14-2003, 07:51 PM	#13
Doctor DeBo Registered Member Join Date: Feb 2000 Location: Newnan, GA, UnitedStates Posts: 83	Well I figured out my charging problem and it can be blamed on stupidity.I had removed my A/C way back when I started modifying my car,after my electrical fire I removed my power steering pump and went with a manual rack,this left no pulleys on the left side of the eng.To make this set up work I re-routed my serpentine belt,instead of the belt coming off the alt and up to the water pump it went over to the crank pulley first.Big mistake as the belt made less contact with the alt pulley.So I ordered up a smog elliminator pulley and mounted it on a bracket fabricated from 3/8 steel,put it on the left side of the engine and routed the belt the way the damn thing was supposed to go.I now have 14+ volts.It took me two days to make the bracket and set it up.Its funny how complicated things get when you over look the obvious. __________________ 92LX 5.0 Hatch,4.10 gears Auburn Pro,Mosser axels,alum drive shaft AOD hi ratio gear set,3200 stall TCI conv,Bassani long tube headers/cats,2 chamber flow masters,2.5inch exhaust,331 stroker,alum GT40 heads ported,Omega 1.7 roller rockers,JE forged pistons,Eagle rods,E cam,GT40 upper/lower intake,70mm mass,73mm Pro M bullet,MSD ignition,Cartech fuel sys w/external Aeromotive fuel pump,30lb injectors,Vortech S trim,Tubular front end,D&D coil overs up front

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