My 2001 7.3, on occasion will just crank and not start. At the time it is cranking and not starting I hear a fast clicking under the dash on the drivers side. I'll stop cranking it and try cranking again and it starts. One time I had to stop and start cranking it about 5 times before it would start. So far, knock on wood, I've been able to start it and haven't been stranded. I am hoping someone can help me figure out what this issue is so I can get it resolved before I get stuck somewhere. Any advise as to what to check? Thank you

 

Have you checked the batteries to see if they are putting out the voltage and amps needed? If they are okay, check the solenoid on the starter that pushes the gear out to see if it is sticking.

 

Chattering relays are usually a sign of weak batteries as mentioned. If you have a helper check the voltage while cranking. There are "volt meters" that plug into the outlet in the dash as well but I have no idea how accurate they are.

 

Agreed, likely a battery or solenoid problem.

 

Thanks for the responses, I'll check the batteries.

 

It could also be a dealer installed aftermarket security system. I have one in mine which is tied to a motion detector. If I wait too long to stat the engine after getting in, while I'm getting "situated", the relay starts clicking and the truck will not start. The solution for me is to unlock the doors with the key fob and then it will start. I go one step further, though after unlocking, and re-lock the doors, wait 3-5 seconds, and then unlock... all of which resets the security system completely.

 

Check and clean all of your grounding points, bad grounds cause more electrical issues than people realize. That being said, because it's cranking some, I'd say the posters above are probably correct.

 

Are you running Torque Pro or any kind of bluetooth OBD2 adapter?

Every now and then I will get clicking under the dash and the truck won't start. I reach down and pull the OBD2 BT adapter off and everything's fine.

It seems to happen more often when I have Torque open on my phone. If I have the BT adapter in but Torque closed (not connected to the adapter/truck) it happens much less frequently.

 

Just now getting around to updating this thread, thought I'd update in case anyone else has the same symptoms. It was a bad battery connection. The battery had juice but when I put my meter on the connectors it dropped 2 volts. Cleaned the connectors on the passenger side battery and it cranks like crazy. Thanks for the help...

 

Nice and easy fix, cheap too! I'm glad you got it figured out.

 

Always good to hear what the resolution was - glad it was cheap and easy.