Truck won't start..... Help!!

[Rezford70]

I have a 1970 ford f100 302. I recently changed the alternator and the battery on the truck. After changing these two items on the same day, I attempted to start the truck. It started on the first attempt but stopped running, I tried to restart it and nothing happened. I tried jumping the truck but nothing again. I took the battery off and charged it over night and reinstalled the battery today and tried to start the truck again and all I heard was a thunk and that was it. I tried to start it again but again nothing. I tried to see if light would come on but nothing works no headlights no parking lights no radio. I let it sit for about 30 mins and went out and tried again and it went thunk again and that was it. Can anyone give me some ideas as to what might be wrong with the truck I am at a lost.

[elgemcdlf]

Why did you relpace both items?

[Rezford70]

I replaced both because the truck had been sitting for a few years and I was told the battery was bad and changed that then it was not being charged when it was running so that's when I changed the alternator as well.

[sublimer]

Ok, list of things to do/try:

1. Check all cable connections to and from the battery and alternator, make sure the terminals are clean and have a clean surface to contact and are tight.
2. Try bypassing the starter solenoid to see if you can get it to start that way.
3. Have Autozone or a similar store test your alternator, battery, and starter. Testing a battery can take a good 30 minutes, so make sure you have some time.
4. Make sure the wiring for the alternator is correct!
5. You may have busted your voltage regulator.

I can continue to list things, but try these first...

[Rezford70]

Ok, I did re check the alternator hook up and all is correct on that, all post are clean and connected correctly, I tried by passing the starter solenoid and all that it did was make a thump sound and nothing. When I got into start it I put the key to the on position and the dash light alt and the other red light where on, but once the by pass was attempted all lights went off and now they are not on. I just put a new starter solenoid on as well. So what's next the voltage regulator?

[sublimer]

The lights being off is good. So, yes, I would try the voltage reg as well, I just replaced mine when I was tracing mysterious starting issues a few months ago and it fixed things.

Also, can the engine turn? Does it try to turn when you hear the "thump?" Try to turn the radiator fan a little to see if the engine can turn.

Then, what are the spark plugs like? Are they old? After that, I'm gonna start thinking about the distributor.

[Rezford70]

When the key is turned the only thing that happens is the thump and that's it. Then as stated earlier the ALT light and the other light go off and then nothing. Is there a test that can be done to see if it is the voltage reg that's bad or do I just have to replace it to see if that would be the problem. I have my brother in-law out side recleaning all the connections again. When it happened the first time I thought it was the battery that was not charged enough so I did try to jump start it but even then nothing happened.

Man this is frustrating..... But I do really appreciate the help and I hope that I figure tis out soon,but please keep the help coming as it is very usefull.

[sublimer]

I've been there which is why I'm helping!

I don't know how to test the voltage reg off the top of my head, but they're cheap and in stock usually in parts stores. I think they're about $20.

Can you confirm that the engine will turn and that it's not locked up by trying to spin it yourself?

Start at about 1:10 http://www.youtube.com/watch?v=9PUTfxrP ... hzexs3jxdr

[Rezford70]

Ok so my brother in-law cleaned all the connections and we got it started and running. The new alternator was bad so I had to go and get it replaced. Now with the new alternator on the ALT light will not go off. I have four wires. Two are in a rubber housing which are the battery wire and the field wire I believe and then I have a black wire with a red strip in it which is the ground and then I have a white wire with a brown or black stipe in it where does that get connected to too?

[sublimer]

Ok, well I'm glad that it's running. If the ALT light is on, that means the alternator isn't charging the system. When I put a new alternator in a few months ago, it lasted a week before I had to exchange it. You sound like you've had the exact same problem as me

How many volts is the alternator outputting to the battery?

[Rezford70]

That I do not know I don't have a volt meter on hand so guess I need to get one soon

[Rezford70]

What kind of volt meter is the best to buy I have one that is ac/dc that is used in home.

[sublimer]

I have a cheapo Radio Shack one...I just want to know how many volts the battery has before starting...while starting...and once running. A car battery would output DC.

[Rezford70]

I tried the one I had and nadda it's not picking up anything. I'll try to find one from a friend or neighbor tomorrow. I had it run for about three hours even drive it and still seems to be ok