Charging issues

[SCEADU]

I am running a sb 327 with Edelbrock EFI in my Jeep. I have 3 coolers on it . 1 Black Magic for the rad, 1 B&M for the trans, and 1 B&M for the oil. I have a vintage air A/C unit installed. The electrical system is a Optima Yellow top with a power master 140 amp Alt.

The problem popped up out of the blue. Everything has been in this configuration for about 2 years. The other day my A/C just shut off. After a few seconds it kicked back on. I didn't think anything about it until I was pulling into my driveway and my volt gauge read 11v. I figured that my altenator kicked so I went and bought a new Powermaster and put it on. As soon as I fired up the Jeep the volt gauge went up to 14v. I turned on my fans and then my A/c and immediately the volt meter dropped to 12.5. When I shut everything down the meter stayed at 12.5v. when I turned everything on again the meter dropped to below 12. I scratched my head then went back to Summit and exchanged the alt thinking that it must be a bad one. I installed the new one to the same outcome. Today I ran up to Interstate and asked them to check my yellow top to see if there was a problem with it . They checked it and said that on the surface nothing seemed to be wrong but they gave me a loaner and said they would put a full charge on it and runs some tests. I installed their loaner and the same thing happened . The meter read that the alt was charging and all was good for about 2-3 hours. Now the problem is back again.

Anyone have any ideas?

[10sec.et]

check your battery cables, grounds and connectors at the alt. solder is your friend. first thing i look at with weird electrical problems is ALL of the high amperage connections. no cheesy bolt on batt cable ends either.

[SCEADU]

They are all solder fit conections. With the new PM alt I ran a 1 wire setup and took a ground wire right back to the bat as well.

[af2]

[SCEADU]

Should I move up to a 200A. Should I go to a dual Bat. It s strange that it worked fine for a few years and then it decided that it wanted to quit.

[squeeezer]

check amperage draw on all the fans individually

[clay]

I'll go down another route. If it is a "V" belt setup, check to see if either the belt is old and glazed or if the alternator pulley or crank pullies are worn to the point the belt is bottomed out in the groove and losing surface contact and letting it slip under load. If it is a serpentine I would say check the tensioner, but you would have already basically done that when you replaced the alternator. Clay

[af2]

[clay]

I'll have to argue with you on some of the amperage values. I'll absolutely give you 30 amps on the radiator fan. I think the coolers he mentioned use fairly small fans, I wouldn't give them much more than 10 amps each. He didn't mention MSD, but I think they rate them at 1 amp / 1000 rpm. I can check an A/C clutch, but I would guess 5 to 10 amps to hold it in. A/C fan another 10 amps on high. EFI pump, injectors, etc. throw in another 10 - 15 at the most. Now granted I wouldn't think many alternators could necessarily keep up at idle, but once rpm's come up, I think what he has should work - well it has been working up until now. Now off to the 94 Mustang thread.......Clay

[10sec.et]

[SCEADU]

We have a "WINNER!!!!"


Clay you hit the nail on the head. The belt was glazed. The acc are mounted with Zoops and they don't have much adjustment so belts don't need much wear before they won't work with my setup. With full tension on the belt I could still turn the pulley with my bare fingers. I went and got a new belt for grins and now I start at 14v and even with all my acc's on and headlights I still pull 13v.

[clay]

Cool!! Glad you got if fixed. Clay

[af2]

[Paul P]

Still the correct thing to do is a current survey. This is with a clamp on current probe over the + cable with everything under the sun turned on with the car not running of course. Take that number and add 30% that is the minimum you should have for an alternator. Pretty simple.