I have a 95 f150 with the 4.9l six. Just finished installing a new long block.
During the initial start up, the starter would not operate and the battery terminals started to smoke. Check the impedance from + to ground, it was
2 ohms. took the starter and alternator off. still read 2. trace it to the fuse block and possibly the #20 fuse. not sure where to go from there. any ideas?

Thanks

 

witch fuse block the big one under the hood or the one inside the cab

 

It's the large fuse block under the hood.

 

If the battery was fully charged (is it on a charger right now?), nothing in the fuse block could handle a dead short - the fuse or the fusible link wires at the starter relay would burn instantly.

At what point did the smoking begin? After you turned the key, or the instant you connected the battery?

Study this diagram:

 

I did put the battery on a charger after removing it but,
It should have been ok at the time......

The terminals did not start smoking until the key was turned....

Here's a little more info. The wire the goes from the solenoid next to
The battery to the fuse box reads 2ohms to ground. Remove it from
The fuse box it goes up to 120k. The #20 fuse has the same effect, 2 while
In place, 120k when removed.

Thanks

 

If you read that diagram, you'll see that it's not a solenoid; it's the starter relay. The solenoid is part of the starter, and you can't see it from above.

Where precisely did the smoke come from? If it was either battery terminal, read all these captions:



If it was from the relay, read these:

.

That resistance measurement is meaningless. If something on that circuit was shorted, the fuse would blow - that's its sole function. You're just reading resistance through the normal always-on components in that circuit, like the radio/clock memory & courtesy lights. Look at this diagram:

 

Thanks to everyone for the help. The terminals were very corroded so I did replace them.
The smoking stopped but The motor still wasn"t turning. After further investigation, many sleepless nights and even more added grey hair. It turns out the starter was wired incorrectly. Problem solved.