When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
ok so a guy who works with me has a 68 f100 with unfortunatley a 327 and all Gm electrical. Now for those of you guys that aren't repulsed, the thing has some kind of drain of the alternator. He's only getting 9.5 volts at the battery, and he's checled that circuit backwards and forwards. He also replaced the voltage regulator (i thought that the gm had that incorporated in the alternator). Well he's still scratching his head and has a known drain on the battery when he turns the motor off. Anyway, is there anything that we're missing here? Basically he's about to have to take it to a shop and have the guys look at him wierd for not fixing it himself. I'm telling him to remove that 327 or get a new harness, but I'm joking. Any help would be appreciated.
has he had the alternator itself checked? try that first. i thought my truck had a drain on the battery but the alternator was bad and never kept a charge on the battery.
The early GM systems did have the external voltage regulator.
With the ignition turned off and all accessories turned off disconnect one of the battery terminals. If you get even a small spark while disconnecting or hooking up the battery then you definitely have a drain somewhere.
sorry to rip on your buddy but i really think his problem is the entire motor, ya see, anyone who puts a chebby motor in a ford is cursed from the get go! ,. its almost like eating cookies while drinking a beer! some things just dont belong!
One way to check for the drain is to remove the negative cable from the batter and hook a 12 volt test light between the battery post and the cable you just removed. If you have a drain the light will glow brightly. Then just start unplugging stuff one by one. When the light goes out, you have located the source of the battery drain. Good luck and let us know how he makes out.
jor
he found a few drains, one in the electric choke of the carb, another somewhere else, I can't remember. Thanks for the method, I'll let him know. I think he's gonna sell the truck though, and get something newer. I'm trying to talk him out of it, but ultimatley it's his decision, and I don't have the money to buy it off him.