I have a 2003 F350 5.4L, I posted in the super duty section https://www.ford-trucks.com/forums/1...use-block.html but I guess no one has an answer for me. Is there a relay under the dash or under the hood that controls the Gauges / odometer? My fuse block fried when water got to it. I replaced it with another one that is about 2 revisions older than the original. Everything works now, but when I start the truck it takes about 10 seconds for the gauges and the odometer to come to life. Any help would be appreciated.

Mike

 

The cluster has 3 power sources, all come from the fuse box under the dash. It will be;

hot all the time fuse 35, 10amp

hot in run or acc fuse 33, 15amp

hot in start or run fuse 45 10amp

Your cluster is not made like in the old days where the sending unit wire went directly to the gauge itself. Your cluster is a computer, just like the engine has a computer. The computer gets information over the data network and it does get some information from sending units as well. The computer in the cluster takes this info and then moves the gauges.

Things I do know; These cluster computer systems are very sensitive to voltage fluctuations. There have been many trucks that have had their gauges suddenly go wacky, and the alternator has been the culprit. I would monitor the voltage going to the cluster very closely, and if it looks ok, your brain in the cluster may have something wrong with it.

 

Thank you for that information, I was testing the alternator earlier today, holding steady at 14.45v. I will test those fuse line for voltage fluctuations.
I pulled the battery cables cleaned them and turned the key, all gauges made their dish sweep started truck all gauges laid flat and ne od for 10 seconds. Turned truck off, then turned key on again gauges went to the left and stayed there. Started truck 10 seconds all gauges work. Does the same thing every time, may need to send cluster out for repair. Thanks for the info.
Mike

 

So fuse 35 is good #33 had a 5 amp. I replaced with a 15amp and #45 was ok, replacing the 5 amp with a 15amp everything started working fine, the only problem left to figure out is why the diagnostics sweep isnt working. If I pull fuse 35 and reinsert it works on time. If I do the diagnostics test by holding the sel stem it works but just turning the key to on the needles go to the left and in the off position the speedo stays about 7mph.

 

I ran through the diag test manually from the SEL button 2 DTC's pop up, 9352 and 9360, I know one of them is suppose to mean a low battery, I did have the battery go dead a few times, then I changed the battery, then the fuse block pulled this battery all the way down when the block shorted. Battery checks out fine holds steady at 12.4V, Load tests out at 11.2v after 30 seconds of load. Alternator is putting out 14.45V, so all should be good, I couldn't find what all the numbers on the diag test means though.
I did make a mistake on the gauges, it's my RPM gauge that's stuck at about 700rpm when the truck is off or the key is on. Once it's running, it works fine though, and the gauges are still going tho the left when the key is turned on.I ran through the diag test manually from the SEL button 2 DTC's pop up, 9352 and 9360, I know one of them is suppose to mean a low battery, I did have the battery go dead a few times, then I changed the battery, then the fuse block pulled this battery all the way down when the block shorted. Battery checks out fine holds steady at 12.4V, Load tests out at 11.2v after 30 seconds of load. Alternator is putting out 14.45V, so all should be good, I couldn't find what all the numbers on the diag test means though.
I did make a mistake on the gauges, it's my RPM gauge that's stuck at about 700rpm when the truck is off or the key is on. Once it's running, it works fine though, and the gauges are still going tho the left when the key is turned on.