K, so I need a little help. Here's the set up. Several years back I relocated my battery to the rear hatch. A few month ago I rewired my fuel pump using a 30 amp relay powered directly from the battery. I have been smelling something like an electrical issue for a while but though it was the amp to my subwoofer. Well today I smelled that smell really strong and then my car died. The in-line fuse I installed in the power line from battery to relay actually melted before blowing the fuse. The logic of the wiring seems sound, I checked all of the connections tonight and couldn't see anything wrong. Just to give as much info as possible, I did splice into the ground wire to the pump to add additional grounding near where the wires connect to the pump. This kind'a freaked me out. Fuel pump has been around for 10 to 12 years so wondering if it could just be a bad pump. I don't know how to solve this one so any help would be appreciated.

 

What gauge wire are you using for power?

 

So the wire by the fuse holder melted? What gauge wire are they?

 

I used 12 gage wire with in-line fuse from AutoZone. I showed the burnt up melted wire and fuse holder to my neighbor this morning (used to be an electrician). He offered two thoughts, said I was using two large a fuse (30 amp) and suspected I could have a bad relay and/or a failing fuel pump as there is nothing between the power source and the pump other than the relay. I would have thought if the pump was failing it would just stop pumping fuel. My relay is also a 30 amp, guess that is why I thought I should use a 30 amp fuse. Is 12 gage the wrong size wire, should I be using a different amp relay or can a failing pump cause a wire and fuse to melt? Thanks for your help.

 

Does the fuse holder comes with 12 gauge wire as well? 12 gauge for 30A max is fine as long as you are under 10' of wire, I use 10 gauge for my setup just to be safe. Your wire and relay are setup to handle 30A, and if it goes over 30A due to a bad pump then your fuse should pop, so sounds like part of your wire is having trouble with less than 30A. I would check the melted portion, that's probably where the cockpit is, and check your pump, it might be going bad and driving up the current.

 

I have an electronic battery disconnect switch installed in-line on the hot lead from my battery. It is mounted in the rear drivers side under the little black plastic access hatch (I think the jack tools used to be stored there). My fuel relay is also installed right there. The hot wire runs from the hot side of the remote battery disconnect directly to the relay. it is probably 3 inches of wire including the fuse holder. I went ahead and ordered a new fuel pump as mine has some years on it and I really need more pump than I have. I will also replace the relay just in case and rewire to the new fuel pump when it gets here. Hopefully that will solve it. I was just really surprised that the fuse posts melted and broke off and the wire turned black but the fuse never blew. I don't think I will ever understand electricity.

Thanks for taking the time to respond, I appreciate it. Now all I have to do is figure out how to install a Stealth 340 fuel pump and do a little rewiring. Should be an adventure.