Hey guys, I just joined this forum, so i guess this will be my hello.

Anyway, i have a 91 with a 351w in it. Here for the past few months it has been eating batteries like candy, so i did the whole test light thing with the neg cable and neg post. The test light came on, so i pulled all the fuses out and still nothing, the test light stayed on. My next step was to disconnect the alternator, still the light stayed on. My question is what the hell else can i check to see what circuit has a short in it?

 

so the dome light is out... there isn't a light under the hood? brake lights aren't staying on..... disconnect plugs one at a time. un plug the ecu also

 

the dome light and all the other lights are out, along with the underhood light. I didnt think about the plugs, i didnt know they had power when the truck was off.

 

computer has a memory untill you undo the battery right. what about the radio, clock, ect..

 

Remove the fusible links one at a time. There are things on fusible links that don't have fuses on them.

 

How fast is your battery draining? After you jump it off or put a charger on the batt, does your truck run if you disconnect a batt cable? Does the truck show a charge when running? Could it be your running on batt power alone?

 

all the lights and accessories are off when the truck is

 

My climate control would drain my battery if left on until i rewired it. Try what Steele said and see if it runs with the battery terminal disconnected.

 

Hi bud and welcome to the site. Had another member, Grampajac, is his name. He went through this sequence back in July. Believe he had a car with the same condition, he found his with a milliamp meter, was a controller located under his seat. By disconnecting, cleaning terminals everything was good to go. Suggest sending him a private massage, if he indeed, did fix his problem, am sure he will respond.
If the test light is on connected in series with the neg cable and the lite is on there is a draw. Don't be misled by a dim light. All the keep alive memories involved will have a draw, milliamp stuff. Lite on bright is no good, if enough drain is present, it will kill a battery. PM Grampajac.

 

Sounds like a bad alternator or a parasitic drain.