Every time I connect a trickle charger, the dome light fuse blows

is the 12 volt healthy?

 

maybe a bad charger? are you just putting the trickle on to maintain the 12v while not driving it?

 

Agreed! I'd test a different charger to confirm that it's the source of the problem. If its not the source of the problem then perhaps there's something wrong with the dome light circuit ?

 

I use both a 2 amp and a 4 amp charger on our 2011 Prius, but I don't use the red jump terminal. I have a pigtail SAE connector on one of the empty fuse locations in the back of the fusebox and the ground is under a bolt.

No problems with either.

You might have a short in your dome light circuit.

 

Check your cabin air filter for a mouse-house.

 

Are you connecting the leads onto the car; before plugging-in the trickle charger or after? A 2A charger should be able to pop a 7.5A or 10A dome light fuse. A current surge may pop a fast acting fuse. Also test your positive and negatives are correct; if that charger doesn't check that.

Good Luck....

 

excess current needs to flow across the fuse to pop it. It's as simple as that. Nobody needs a circuit diagram to figure that one out.

Sorry, I mistyped in my previous thread #10:
Are you connecting the leads onto the car; before plugging-in the trickle charger or after? A 2A charger should NOT be able to pop a 7.5A or 10A dome light fuse. A current surge may pop a fast acting fuse. Also test your positive and negatives are correct; if your charger doesn't automatically check that.

 

Now, that does remind me of a warning that was printed in the manual for a bench power supply I've got, and could also apply with a charger.

The supply or charger may have large filtering capacitors on its output. If you connect it, while off, into a circuit where voltage is already present from some other source, there can be a big slosh of current backwards into the supply, charging its output caps until they match the circuit voltage.

That shouldn't happen if the supply/charger is already on, producing a voltage close to what's on the circuit, before you connect it in.

Curious, though, that any such current would be flowing through the dome fuse. Is there any add-on accessory, by any chance, on that circuit, that might have its own battery or energy storage inside of it?