i have a 1984 f150 with a 5.0. It has been through 3 silinoids in the past 2 months (they have been hooked up correctly i quadruple checked them). first off something is draining the battery. you can take a DVOM and watch the battery go from 12.3 to 2.8 in a couple minutes. I tried to start it up today and the silinoid did the magic fast click so i tried to jump the starter right to the battery and it made a sound like the old buzz box welders. Could a starter drain the battery and make a silinoid click or is it something else? I do NOT want to sell it but its becoming a money pit.

 

Fix the battery drain and your solenoid will stop clicking. It's clicking and buzzing because the battery is low. It was buzzing when you jumped it because you had a poor connection on your jumper cables.

Hook a testlight up like the diagram below. If the testlight glows bright you do have a drain. Go in and pull each fuse one at a time till the light goes out. Make sure to shut the door each time, the domelight will foul the test.

If the light never goes out, pull the wires off the alternator and see if it goes out. If it does, then your alternator is bad.

Any added equipment at the battery light inverters or amplifiers, pull them off too and see if the light goes out. Once the light goes out, you found your drain.

 

awesome! thank you very much for this! ive never seen this before, i just spend hours on end having my head in a chilton book. Ill try this after dinner and ill get back to you.

 

Feel the back of your alternator to see if it is warm or hot after you connect the battery.

A big drain like that has to be going somewhere.

 

I love the test light for finding drains on the batt.
I would also have the batt checked out. Make sure the water level is good and do a full charge. Once charged have it load tested as it could be bad after all this charging & re-charging.
Dave ----

 

Bad battery sounds like.
12v to 2v in a couple minutes? That ain't right.
Should take a lot longer.

 

If it's not bad now it will be pretty quick

 

A good battery that is low will do that. Most batteries will read 12v if they are charged or discharged. When you put them under load, that's when the true condition of the battery can be determined, and a low battery will quickly drop from 12v to something lower, depending on how discharged it is.

That's why some of the battery checkers you see have large load resistors in them that smoke when you hit the button to get a reading.

 

Right, but automotive start batteries can be ruined by resting voltage levels below 11 volts.

 

well just did the test light test and no light came on and i didnt unhook anything, i charge the battery and it drains and when i turn the key on the dome light goes out so im guessing bad battery? freaking battery is new only had 4-5 starts on it. so there has to be something killing the batteries i put in there what would that be

 

Dead cell in the battery maybe. Some auto parts houses leave those things on the shelf til they sell and they can be bad sitting there after a while.

Pull it, have them load test it and see what shakes. if its a new battery the warranty will take care of the rest.

And as always never assume, K.I.S. keep it simple you will find the issue its in there somewhere you just gotta dig it up.

 

Take the testlight and put one side on the battery negative and put the other side on the +. Leave everything hooked up in the truck as normal. The testlight should light up off the battery power. Keep it on there, and then open the door so the domelight comes on and then fizzles out. Keep the door open, has the testlight fizzled also? If it has, something is wrong with the battery. If the testlight is still bright, you have a poor/bad connection somewhere between the battery and the rest of the truck. If that's the case report back, we can walk you through trying to find it.

 

the battery is bad im guessing but i tried to start it with a jump pack, it turns over but turns over really slow. another question, could my ignition switch kill my battery like that?

 

Do you have a way to take the battery out and fully charge it?
Are you just going to replace the battery?

It is not likely the ignition switch itself killing the battery.
But, something else that is always connected or 'on'.
And something with a substantial draw...

It's not unusual that a jump pack is not able to start the truck by itself.
Having some current available makes the diagnosis a lot easier.

 

Taking the instructions is post #2 a step further, remove the positive cable at the fender starter relay.
Connect the test light and individually test each of the wires that were bolted down with the positive cable.