HELP! Battery dies after sitting! I think starter solenoid is at fault?!
 

Hi! I have a 79 F250 with a 400/C6. Anyway, after sitting for just a couple hours, the battery is dead. When I went to jump it using another car, the starter solenoid started smoking. This is also funny because I had the keys to the truck in my pocket (NOT IN THE IGNITION) and the truck started turning over VERY slowly. The engine actually started cranking over by itself very slowly. Like I said, after driving the vehicle just once or letting it sit just a half hour or so, the battery is dead. I know its not the battery, I just put a new one in it and it still does it. Does anyone think the starter solenoid could do this?

Possibly or it could be the ignition switch. Try unhooking the small "S" wire the next time that you park it. If the solenoid stays hot and drains the battery, then yes it's the solenoid if not then it's something else. With the key off, if you have a voltmeter, you chan check for voltage in the "S" wire.(unhooked from solenoid)

buy a new battery and a starter solinoid.

What is the "S" wire? Is it on the solenoid? Also, 390GasHog, I put a new battery in it.

Clean all your connections (including grounds)

I say your starter is shot (shorting out)

Remove it and try booster cables on it for bench testing.


He meant the S terminal wire on the solenoid .
It should be the one closest to the battery.

Starter Woes....
 

There are two things that can cause your truck to turn over without your keys in the ignition. First, you are right, the solenoid could be stuck. Secondly, your ignition could be powering it up all the time. Check the little wire (s) nearest the battery for voltage without the key in the ignition. If there is power, well it is coming from somewhere, it could be that the ignition switch is shot, but they generally get really loose, or difficult to turn when they are worn out. Also, they rarely short, they generally just go open and nothing works. Also, if you don't have any lights sticking on anywhere and I am assuming you have checked that, I would suspect the alternator, the regulator, but the starter is unlikely. Does your alternator light come on when the key is on and then go off once the engine starts? If not, you likely have charging system problems (regulator,alternator, or wiring). Your alternator and regulator can drain the battery very quickly if it is worn out and grounded (shorted). It would be very hard for the starter to do this because it doesn't have any power to it if the solenoid is working correctly (it gets all of its power through this switch). So, I suspect the starter is probably still good. However, the starter could be drawing way too many amps and that would fry the solenoid in a hurry and cause it to stick like it did. Let me know what you find.

T.R. Bauer

Either the starter relay is internally shorted or power is being supplied to the S terminal to cause it to close, probably from a bad ignition switch. Be careful though, if the switch is shorted (I have experienced this,) it is probably due to an internal short in the starter. A dead short in the starter circuit will weld the contacts (kids don't try this at home.) If you replace the relay, the starter may just eat that one too. Sometimes it seems easier to just replace components, but in old vehicles, the wiring is just as likely at fault. There is no substitute for good troubleshooting (I know from my mistakes.)

Starter solenoids can LOCK-UP in the crank starter position (Electrical contacts Internally) from trying to start the engine using an almost dead battery.

Maybe hook up a fresh fully charged battery after checking out the starter.

If solenoid was smoking and not the thick gauged battery cables, then replace the starter solenoid, sometimes a smoking battery cables can be mistaken for a bad soleniod.

Check the battery by giving the battery a charge. Check the state of the battery after the battery has charged. If battery is at fault, replace it.

>When I went to jump it using another car,
>the starter solenoid started smoking.
>This is also funny because I had the keys
>to the truck in my pocket (NOT IN THE IGNITION)
>and the truck started turning over VERY slowly.

With battery installed. With a voltage meter, and the starter engaged, check the voltage drop of the battery and check if the battery cables are getting hot when trying to start the engine. If cables are getting hot, the starter is drawing to much of the battery power. REPLACE THE STARTER. I have encountered bad starter which crank by themselves without someone trying to start the engine.

Ford Starter Soleniod Test with the Ignition Switch in the Start Positon.
 

Run the jumper wire from the positive "+" side of the battery terminal or post, to where the red with black stripe wire mounts to the "s" terminal on starter solenoid terminal (the metal stud where the ignition switch gives positive "+" voltage to the solenoid) and check if the starter engages. Note: make sure your truck is in neutral position if a manual transmission.

Another quick test is pull the red with black stripe wire connector at the "s" terminal on starter solenoid "this is the wire that supplies positive voltage when turn the ignition switch to the start postion" and with a voltage meter verify you are getting positive "+" voltage to that red with black stripe wire connector when you turn the ignition switch to the start position. If you got juice at this connector, then the starter solenoid is not engaging, THEN YOU WILL NEED TO REPLACE THE STARTER SOLENOID.

_________
Richard