My 1968 f100 (360) will not start. When I turn the key, I get one click at the starter relay and nothing more. The battery checks at 12.5 and most of charging/starting system is new (alt,battery,regulator,dist,plug wires,coil,battery cables). Recent addition are: plugs,cap & rotor, Petronix ll ignition, which worked great for two weeks. I'm going to replace the ignition switch, which has been a problem in the past. It would turn over correctly, just none of the dash gages would work. If I moved the key around a little, everything would pop up and work correctly for 50 start ups after. I'm also changing out the starter today to finish that end of the project. Thanks

 

Chromepro > Make sure the truck is in park if automatic transmission or in neutral if the truck is a manual transmission, block wheels. For this test, jump with an electrical wire the starter solenoid assembly (mounted on firewall near the battery) with a jumper wire from the positive side of the battery to the small red wire on the solenoid assembly. this jumper wire should engage the solenoid and engage the starter. What does it do?

The next test. Make sure the truck is in park (if automatic transmission) or in neutral if the truck is a manual transmission, block wheels. Get a set of jumper cables. Hook the jumper cable from the positive terminal on the batter to the battery cable that runs to the starter on the solenoid assembly. Make sure it not the battery cable that runs to the batter. What does it do?

These are dianostic test to isolate if it a solenoid assembly or starter problem. These test will also help is it some other electrical related problem.

 

UPDATE: Before anything, I tried to start the truck and it S.L.O.W.L.Y turned over and ran normally. Upon turning it off and its back to clicking at the solenoid only. The battery checks at 12.3 but drops to 6 upon attempting to start. Me thinks we have a battery/charging system problem. The battery is a new Optima. Time to pull out the meter a see whats pulling the juice. Any ideas would be must helpful, Thanks!

 

I believe a fully charged battery should read about 13.2 volts. The symptoms you give are indicative of a low battery. What causes a new battery to be low? Charging system malfunction or short in system.

Good Luck
Gator

 

More to the story: Gave it another try after charging the battery fully. No start this time, only clicking at the solenoid and a small hum from the starter. But in addition a little smoke off the starter as well. Forgot to mention that I gave the starter a couple wacks before it turned over last time... Now I'm really at a lost, is it starter or charging system or both?? After the starter had it's little smoke session the battery was down again. Question...everything was fine until recently and I was thinking that I just replaced the blown cab light. Would it be possible that its not grounded properly, though it seems bright it does dim on startup. It off when the doors are closed, but it could still be pulling power?? Thank you again!

 

It could be a alternator or voltage regulator or a battery that went out.

 

Your reply reminded me of an incident many years ago. A C****y van that I had suffered a similar malady. Turned out that the starter was slightly misaligned in its mounting hole. This put the bendix gear in a bind, and thus required excessive amperage to turn the starter. It worked OK for a while
but the excess draw eventually fried the starter. Maybe???

Gator

 

I had the same symptoms and it was a loose ground cable

 

In order for a starter motor to crank a motor it needs a certian quantity of power. Power equls watts. Ohm's law states that voltsxamps=watts. therefore 12 voltsx200amps(normal draw for a ford starter) = 2400watts. IF you have a battery that is bad, it is possible for it to maintain amperage but not voltage. Your starter requires 2400watts. It doesn't care how it gets it, but it wants it. So if your battery voltage drops to 6 volts when cranking... 2400 watts / 6 volts = 400amps. Not good. On the other hand if you were to hook the same started up to 24 volts, (not advised) 2400 watts / 24 volts = 100 amps. See where I am going? Basically a rule of thumb is, A bad battery will KILL a good starter due to the high amps. I suggest you put a load test on the battery. Most parts stores can do this. (A load tester is basically a toaster with a meter!) They will be able to tell if the battery is bad. Do this before you spend any money of parts!!! If the battery cannot put out, all the new parts you put in won't make a difference and you risk bar-b q'ing them! I have seen starters smoke, solenoids stick (contacts welded shut from high amps) and cables glow. All from a bad battery. Your charging system might be fine, do the load test FIRST!!! Good luck bud, let us know.

 

If the starter is smoking, it is fried, replace starter.

Make sure your getting a good ground. Take the negative battery cable off, not the one on the battery post, the one mounting to the engine, Sand with sand paper both the cable and the location where the cable goes, put a new bolt if neccessary when reinstalling. Also, Check the positive battery connection at the starter solenoid, remove, sand and reinstall.

 

Not to argue, but it depends how much smoke was let out of the starter. I ran one that had smoked before for about 2 years before I had to replace it.

 

If hitting the starter got it to work then the brushes in the starter are worn out. When you hit the starter it jats the brushes enough to make contact for the one start.

 

Once again: Cleaned all contacts (ie: block, battery, solenoid, cable ends, ect.) and replaced battery with my other truck, which is my daily runner. It still just clicks, but no smoke just a little hum from starter. I tried tapping on it to no avail either. Now my next chore, as I'm unable to get the starter out from behind the header, even unbolted and moved in every position (knew I should have take that welding class). I'm going to have it towed to pipe shop today and I'll replace the starter in the lot. Thanks for your assistance again!

 

If you can not get starter from behind the header, if you have headers on this truck, you will need to take the header and the starter off togather. When you put it back, you my want to think about a heat shield to keep the starter from over heating agian.

 

I'm with bertha, yank that starter out and get a good one. While you have it out, hang a heat shield on it or around it. Those headers will just about halve its lifetime. Yrs ago I went thru 3 starters until I wrapped the starter with fire cloth. There are also aftermarket heat shields that will do the job too. You have to unbolt those headers too, and make sure to run a tap and blow the junk out of the hole with an air nozzle. I use a can of compressed air if I'm not close to my compressor. Use NEW header bolts to rehang them. I would recommend some anti sieze juice on them too, (for the next time you have to unbolt it).