For those without fancy tools such as a $3 multimeter, I present an easy way to tell if the alternator is working.
Find something metal that will attract a magnet, something like a wrench or screwdriver. With the vehicle running, stick it to the bearing on the back of the alternator. If it sticks, alternator is working. If no sticky, no worky.
You have a truck motor? I thought yours was a mustang with a mass air?Originally Posted by 85cj7
-Karl
2006 Chevy K3500 4X4 - No J.B. Weld on it yet!
1982 thru 94 F-Series "The Klogger" AKA Transport on the road, on the trail, or on the trailer!
1965 Chevelle
1975 Corvette
it is. 302 H.O. from GT 90 mustang. so yes it is mass air
Last edited by 85cj7; 02-24-2010 at 12:34 AM.
or when its running, take the pos batt cable off. If it stays on the alternator is running, if not its not
That doesn't work on EFI.
'91 Bronco 351w, ZF5, D44 TTB, 9" rear swap with disk brakes, 37" toyos, method wheels, mastercraft seats, A/C and heat
Actually it does....
-Karl
2006 Chevy K3500 4X4 - No J.B. Weld on it yet!
1982 thru 94 F-Series "The Klogger" AKA Transport on the road, on the trail, or on the trailer!
1965 Chevelle
1975 Corvette
The computer needs a closed circuit to work, so when you disconnect the battery it shuts off whether you have a good alternator or a bad one. That's what I was told at least.
'91 Bronco 351w, ZF5, D44 TTB, 9" rear swap with disk brakes, 37" toyos, method wheels, mastercraft seats, A/C and heat
Optimas have smaller posts and sometimes do this trick for you. I can say that YJ's, CJ's, F150s, and Land Rovers all are capable of running with the battery disconnected at either post.
...
ask him how he knows....
Ryan Clarke
(214)695-7901
The computer needs a negative battery pole (a place for everything to tie into) for the ground to tie into, if you have bad battery connections what Flem was talking about can happen. But like Flem said you can remove the battery from a running EFI vehicle.
-Karl
2006 Chevy K3500 4X4 - No J.B. Weld on it yet!
1982 thru 94 F-Series "The Klogger" AKA Transport on the road, on the trail, or on the trailer!
1965 Chevelle
1975 Corvette
I don't get the "won't rev over 2k" part...this isn't a drive by wire... Maybe something like a weak alternator combined with a bad coil or ecm just barely getting the voltage it needs to run, and not enough to put out a bigger high-rpm spark?
and for the record, disconnect the positive post on a 350 vortec-equipped pickup or tahoe and the truck will shut off
I went to autozone and they gave me a new alternator even though my old one passed the test. I put the new one on, and still had the problem. Then I checked the headlights and the passenger headlight was barely working so i pulled it out of the housing and turned the headlights on, and the problem was gone. So something in the headlight was causing the engine to die when you turned the headlights on, I'm guessing too much condensation inside the headlight housing or a loose wire somewhere, but either way, the problem is gone and the truck runs fine now.
'91 Bronco 351w, ZF5, D44 TTB, 9" rear swap with disk brakes, 37" toyos, method wheels, mastercraft seats, A/C and heat
bad grounds make things act funny
Red 81 CJ5, 35's, 4.10 and detroit, 4 to 1 dana 300, tbi efi, flat belly, cage, chromos and auzzie in front... sometimes runs. body damage to come
glad you got it fixed, and you got a newer alternator out of the deal.
I went on the trip to BMRA this weekend, and had tons of fun and my truck, yet again, surpassed my expectations. I only incurred minor body damage. But my transmission is getting really worn out. When accelerating from a stop the truck shakes a lot, an flip flops between first and second gear a lot, but once I get up to highway speed, everything seems pretty smooth. Sound like time to look into rebuilding the E4OD?
'91 Bronco 351w, ZF5, D44 TTB, 9" rear swap with disk brakes, 37" toyos, method wheels, mastercraft seats, A/C and heat
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