A few weeks ago my 2001 F350 - 7.3 - started having problems starting. Mainly when I tried to start it after the truck had been sitting a for a few hours..

When I would turn the Key to the Run position I would hear a fast clicking sound under my dash. If I continued to turn the key to the start position the truck would crank but would not start.

I could turn the key back to the off position after hearing the clicking sound and then back to the on position a few times until it didn't make the clicking sound - then the truck would start..

This went on for about 2 - 3 weeks until one day it would click everytime I turned on the key. Being stuck at Work - after work hours I decided to find this click sound and Do something..

The clicking was coming from under my dash - just under the Radio. I ended up pulling the Panel that exposes your fuse panel - then under the AC and Radio there is a cluster of wires plugged into 3 relays. 2 small relays and 1 large.

When I would try to start the engine I could feel the clicking sound I heard from those relays..
I squeezed on the three relays and tried to start the engine and it worked. However the next day I still had the clicking sound and no start..

I took the 2 smaller relays (both being the same - part # F57B-14B192-AA) and swapped them with each other. Putting the Top on into the bottom slot and bla bla bla.

No more clicking when I try to start my truck - no more problem..

I haven't seen anything else start to fail from this (so far).

My question is - does anyone know what those relays control?
My point is - if anyone else has this problem - this worked for me..

 

I think you have a battery problem.......when they get low...... relays will start chattering. I'd have the batteries load tested. Just a thought.

 

What touchofgrey said, and in addition, I would replace the relays just to be safe.

 

I agree with the batteries too. Replaced my batteries last winter when the relays started clicking.

 

I have heard the same thing after, I replaced the batteries, starter, starter relay, and glow plug relay. My truck was not turning over like it should have. I first replaced the batteries, it was a little better but still was right. I went and bought a new starter. After I replaced starter, I started hearing the clicking sound like you discribe in your post, but my starting (slow turning over) issue was fixed after I put the new starter on. I then went and bought the Starter Relay and Glow Plug Relay. I can still hear the clicking every once in a while, but it has never failed to start.

 

happened to me in my 03,just replace the relay and it will be fine.

 

Thanks all for the reply back.

Being in the Phoenix Az area my batterys get replaced once a year (like it or not). something about the heat I guess kills them.
I will however check my battery connections and stuff - as well replace the relays (or at least buy a backup set just in case).

I had noticed that my starting seems to be a little slower than normal.

Thanks again for the inputs.

 

i have also noticed slower cranking and had the relay clicking but it was a relay under the hood in the power distrubing box...every now and then my truck would just crank for a half second and start clicking and sometimes it wont be able to get jumped off...we checked for a draw and ended up having a 4 amp draw...i pulled each fuse out and even unpluged my remote start/keyless entry/alarm and nothing still a 4 amp draw...i pull the relay that is clicking and switch it with another and it still clicks in the original position even with the other relay...i just dont know

 

How about the amps driving those 12's. Are they run straight off the battery?

 

right now i got 2 amps powering 3 12s and the power wire goes straight to the battery but both amps have remote wires going to the cd player so the amps dont turn on til the cd player comes on

 

Bumping this old thread. I posted yesterday that I am not geting any fuel pressure. Putting a test light on the pump I was not getting juice to it. I got a tip hear to look for these relays. I got the radio ouf and found the three relays. The larger is obviously for the flasher since I can feel it while that is on. The other two I was told one was for the fuel pump, and not sure on the other. When I swapped them I still did not get fuel pressure. Anyone know what the other one is for so I can test that and see if the relay is working for that one? That way I can hopefully tell if it is two bad relays or bad wiring. I knopw my interior dome lights have never worked with the door coming open, so maybe it is a relay for that? Thanks in advance.

 

See if you can find the same type relay under the hood and use them to swap.

 

I was able to swap with the washer pump relay and tested all three to be good. Anyone know what pin to put a meter or test light on with the relay to see if it is getting power to it properly?

 

The relays have a diagram on them with pin-out designation.

 

Think I found the issue. Down by the pump there is a length of wire not protected by the wiring loom that looks pretty corroded. I'll replace that and I think it will do the trick. Had to happen on a cold rainy day though. @#$%&*

Thanks for everyone's help.