F150 5.4L XLT battery good, was running and starting fine. When try to start get a clicking noise in fuse box under dash. Fuse number(relay) 2.

 

If your battery is tested good and you haven't already, remove and clean your battery cable clamps and the battery posts.

 

mine did the same and it was the battery.

 

Another vote for a bad battery.

 

It is acting like a bad battery. Either your battery is bad or your cables getting power to the vehicle are dirty. That is how they act when they don't have enough power to start.

 

agreed on the battery.... if the battery is fine id say test the starter on the tranny not the firewall...


EDIT: that is if its not turning over but the celanoid is still putting through a charge to ur gauges*

 

One more vote for the battery! When mine went, the truck never gave any indication of being bad. I had made several stops that day, and got into the truck and tried starting it.

Just heard clicks from the fuse area. Really didn't think it was the battery, because I had driven about 20 miles between each stop.

Yes, it was the battery!

 

when my truck did this it was the solenoid on the firewall.. I always start with the cheapest thing first. Cross the terminals with a screw driver with the key in the run position and see if it starts up then. If so then thats your problem its a 10 minute fix make sure you disconnect the battery

 

After swapping the battery which needed to be done anyway, still didn’t crank. Then my husband discovered the loose cables! Started right up!

 

Why you hear clicking relay:
.
As soon as the start relay operates, the starter tries to draw a large current.
If the battery is either down on charge, has an near open inter-cell connector or there is a high resistance in the cables, the voltage DROPS .
The voltage drop causes the start relay to "release" and the cycle begins all over again. (clicking)
Power to other systems sees the same condition.
Good luck.