Ford think fuses

Recently, we swapped batteries. Voltages are same, wiring is identical but the 3rd fuse (10amp) blows once the service switch is switched on. I’ve traced wires and have not found any shorts and not sure where to look next. Any ideas?


You need to do a full review of everything you touched/removed/reinstalled for this battery swap.

Start at one end (B-) and identify each wire that is attached at that battery post and make sure it actually supposed to go there.

I know it may be stupid but verify that you started off correct and got the first battery in correctly. It is easy to mess up. You say the voltage is the same but is it backwards?

Go to page 123 in the electrical section of the service manual. That fuse supplies power to the instrument cluster and motor controller. So, unplug both and see if you still have a short. Make sure you’re using high voltage fuses and not 12 volt fuses.

Update. I checked everything recommended and found nothing unusual. I did swap the fuse block and the popping fuse symptom went away. However, the next issue… the high volt relay is not engaging when the ignition is turned on. The display does not illuminate, there no clicks and no beeps. I tested the ignition switch and there is continuity between every position and lead. Could a bad cluster cause this issue? Is there a hidden fuse I may be overlooking? Again, any guidance would be greatly appreciated! Also, batteries are fully charged. Thanks!

Go to page 202 and 203 in the electrical section. Check all power and grounds to cluster. If they’re all good contact Bob the Cluster Guy in Florida. Voltage return means ground.

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For anyone interested… the cluster was confirmed bad. We swapped with another one from a parts cart and it turned on immediately.

Now, to figure out what caused the failure/surge in the first place…

Thanks for all the help!

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