My 79' f150 wont start!!! I had put a new battey in and alternator and voltage regulator, started it once to adjust the timing and now it wont start again. When I turn the key it makes a machine gun clicking sound what sounds to be out of the soloid. I ttried to jump it and the clicking sound stops but it cranks very slow. Before I replaced the alternator and voltage regulator it would start fine. When I timed it I put it on the TDC mark. No idea what happened or where to start. Please help!!

 

The clicking you are hearing is coming from the starter solenoid and is called relay chatter. This happens when the voltage at the solenoid is too low. What happens is when you turn the key, the voltage at the 'S' post on the solenoid is just enough for the solenoid to make, and the load of the starter is introduced to the battery. This lowers the battery voltage, the solenoid lets go, and the battery voltage is brought back up. The battery voltage floats around the make voltage of the solenoid, and the solenoid opens and closes rapidly. This explains the "chatter" sound you are hearing.

Here is what you need to check. Both posts on the battery need to be clean and free of corrosion. Check that both battery cables are in healthy condition and clamped tightly. The positive battery cable runs from the positive post on the battery to the large lug on the solenoid, closest to the battery. The large lug on the other side of the solenoid runs to the starter. The negative battery cable runs from the negative post on the battery to the engine block. Check that all these connections are tight, free of corrosion, and not burned. Lastly, check 2 things - check that you have a ground strap from the block to sheet metal (firewall, etc) and that the solenoid body is secured to the fenderwell properly. This is how the solenoid grounds - without a healthy return path to ground, the solenoid cannot make.

And, most importantly, check your battery voltage. It's possible while you had the motor running that first time, you did not have the alternator connected correctly, and the battery wouldn't have charged. Your battery could simply be drained. This would also explain the relay chatter.

Check everything I have listed, and do not take shortcuts.

 

You for got to tell him that the solenoid could have went bad itself and to replace that. They make that clicking sound when they go bad. He already has a new battery in there, I do agree to check everything else....but if it still does it, it is only a few $$ part.

 

I didn't list it because I don't think it's the culprit. The clicking sound means it's making and releasing, back and forth. Relay chatter is due to low voltage. If the solenoid was bad, it'd make no noise at all. The sound lets you know the slug is moving freely inside which is a good thing.

If he checked everything and still reported a problem, I might recommend trying a new solenoid as a last-ditch effort, but only after a thurough diagnosis do I recommend replacing parts. You're right in that it doesn't cost much to replace, but only after he tells me everything there is to know about his battery cables, etc would I recommend spending money on new parts. It looks like you are saying the same thing.

 

I checked every thing but couldnt find a ground strap that goes from the block to the sheetmetal. Later today I am going to pick up a new negative post battery clamp. after that I will check again.

 

"The clicking you are hearing is coming from the starter solenoid and is
called relay chatter. ..."

FMC, that post was a masterpiece! :)

Now, if we could just get these guys to buy a cheap analog meter instead
of spending money on swapping parts... ;)

A meter would tell the OP if he's got the alternator hooked up right and
whether he should buy a new "starter solenoid actuated relay" or not.

34 years and my original is still working fine.
I have a new one I tested in the cross bed tool box tho. ;)

OP, you've got a bunch of new parts might as well finish the job by installing
a new engine-to-body ground wire. :)

http://www.panix.com/~alvinj/file12/speedcontrol1.jpg
Can you see mine there above the insulated A/C hose?
And at the base of the speed-control's servo too?

No big deal. ;)

While taking pictures was just thinking about ways for the negative battery
to get from the engine to the body and realized one way was through the
carburetor's throttle shaft to the linkage to the zinc pedal crank base.

Don't sound all that good to me! LOL :) YMMV on than? ;)

Another on my pickup might be the clutch "fork" etc, but I'm betting it's not.
{edit: thought of another path...}
The emergency brake system through the axle and drive line.

Alvin in AZ

 

I changed the battery terminals and tested the battery.
The battery was charged still.
all the wires looked good.
but still chattering.
battery post are clean.
soleniod is secured to firewall snug.
is there a way to test a solenoid?

 

You didn't follow up on whether you found a ground strap or not. The sheetmetal on your truck has to ground to the block somehow. Body mounts aren't a guaranteed path for electricity. And even then, motor mounts are definitely not. The only guaranteed ground in the vehicle is the engine block. Ground straps are what is responsible for grounding the sheet metal, which makes it possible to ground things like tail lights, radios, voltage regulators, starter solenoids, etc to sheet metal.

After you verify this (don't ignore this, everyone does, and wonders why they have problems! ), here is another test you can try. Disconnect the starter cable from the heavy lug on the starter solenoid. This will free the solenoid of any load. Disconnect the small wire that connects to the 'S' post on the solenoid. Take a flat blade screwdriver and jump the heavy lug that connects to the battery, to the 'S' post. The solenoid should click just once. The click is pretty forceful, and you'll feel it in the screwdriver. After you remove the screwdriver, the solenoid will let go. That's how you test the solenoid.

Finally - what are you using to verify the battery is "charged?" We need numbers here. Just like Alvin says, you need a meter. Check the actual voltage. While battery voltage is technically not an indicator of battery charge (they are not completely correlated), on a fairly new battery, it's usually safe to assume that a voltage of 11.5 - 12 volts is healthy enough to start a vehicle.

 

I still cant find a ground strap. Can you post a picture of one? I did test the solenoid and it did click once then released.

 

CANCEL LAST POST!!!
I found it in the same spot as alvin in az. It is by the carb on the block to the firewall.

 

fmc400,
Your posts are so easy and informative to read. The knowledge is like a magician showing his book of tricks. I still think that your thread on carbs should have been a stickie.

 

Just to add new batteries should be chceked for it's state of charge, because most people know that a battery that sits has a rate of discharge that is affected by temperature.

Usally this is done with a specific gravity battery tester. But I always just throw the charger on the battery, ( iahave one that shuts off after full charge is achieved so as not to overcharge the battery) just for good meansure.

Even so, most new lead acid batteries still should show around 12.4 to 12.6V. If not the battery has been sitting for some time and should be charged up.

And like these guys said, definitly make sure your engine and chassis grounds are good. Because you have to figure that the high currrent draw of the starter has to go some where and the return path is usually through the starter case, kind of like the single wire alternators. You have to have a good return path from the actual engine block to the chassis where the battery ground is. If not this can lead to another problem besides hard/poor or no starting situations. This can lead to stray currents running throughout the drive train and other areas. Which most don't think about, but if your get stray currents running through these areas, and the fact there are many different types of metal used, it can lead to a galvanic action, and lead to deteriation parts.

PS- Ever have a battery question, just about everything you want to know about batteries.
Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and

 

Using an analog meter is the best way to hunt electrical trouble. IMO

Like FMC said, the battery voltage isn't the key to a charged battery but
a battery's voltage under load can tell you something about the state of
charge tho. And, tell you what the rest of the system is like too.

Get a meter (or better yet a friend with a meter) and put it on a vehicle's
battery posts (not the clamps. Side post batteries are another matter and
cussing ain't allowed on FTE so I'll just drop it) and read the voltage.

Should be about 12 volts. :) Dead or alive that's what it should read. :)

While watching the meter's needle have someone start it and notice how
far the needle drops...

Down to about 11 volts or maybe a little lower if it's old.

Now that's a battery's state-of-charge test. :)

Meanwhile back at the ranch... the engine's running, so have the helper
rev it up just a little bit and see the voltage go up to 13 volts or more.

Now that's a charging system test.

Do it on a good vehicle first then try it on your ol' broke down pickup truck. ;)

Alvin in AZ
ps- Checker and Auto Zone both sell a cheap analog meter
pps- cheaper than most new automotive electrical parts, BTW ;)

 

Have the analog meter, the battery is on the trickle charger, and will do the battery test under load tomarrow.

 

Cool! :)

Alvin in AZ
ps- like the way you spelled tomorrow, it's the way I say it ;)