when i attempt to start my 98 f150 4.6L v8, i get a single click and the engine will not start. I tried to jump start the truck and still no start. Attempted to jump the truck on the solenoid and same thing.
had the starter tested a few weeks back and it passed. The battery is new and the alternator is just over a year old...
I am planning to buy a new f150 soon, but want to make sure the truck starts so i can get trade in value...
any ideas on what to do?

 

Try turning the engine by hand using a breaker bar. Make sure the engine is not locked up either from a hydrolock or some other reason.

 

Yea try the breaker bar idea and if it turns over then sometimes starters pass the tests cause there's no load on them.

I had an old car and the starter would pass the test at Autozone but it wouldn't start for me so I took it back and had it retested and they looked closer and realized it was also taking a lot more amperage to turn it over some reason so i just replaced the thing and it was good till I sold the car anyhow.

I've also seen cars with what seemed to be dead spots in the starter where the starter would start and start and start then it wouldn't till you turned the ignition on and off like 20times and yet it still passed the test also and it never did it again after being changed out either.
And if you're just going to sell it just buy a used one off ebay or at a junkyard haha it's a dealership anyhow not like they ever give you top value for vehicles!

 

Clean the cable connections down at the starter.

 

Yes and also take a good look at the condition of the large primary cable that connects to the starter. Mine wouldn't start and i found that the cable inside the first inch or so of insulation was corroded so bad that no power could conduct through it. I had to cut some off and solder a new lug on. It was a problem on some earlier models. Mine would not click at all when the key was turned though.