Contour Enthusiasts Group Archives Forums General Troubleshooting Damaged wiring under battery (info)

Replaced the water pump on my Mystique ('97, alloys, V6, otherwise stock) last weekend. Found something a bit interesting along the way that I thought I'd share...

Those of us who have been around cars a little know what the area around, and especially UNDER, the battery can look like. Sooner or later, a little bit of acid will find its way out of the battery and drip downward. Between that and maybe a little galvanic action, it's no mystery why the area always gets a little rust.

This is a salute (see that finger there?) to the genius at Ford that decided to route big, fat +12 volt wires UNDER the battery, at least in the Mystique. While working on mine, I noticed a loom of wires going between the fuse box next to the battery and the positive battery cable. The insulation on a few of the biggest ones was just cracking and flaking right off! Yes, that's right - big, fat, bare wires connected right to positive battery just dangling about in the engine compartment. All you need is good contact with any of that other metal down there and you get a dead short to ground. Worst case, you weld a little and blow up your battery. Even a little contact, and you might see a recurring problem with strange battery discharge and that nasty burnt insulation smell under the hood.

Well, I fixed it for now. I repaired the offending wires and protected them as best I could, but was unable to reroute them just yet. Oh yeah, if you want to solder wires that have been corroded a bit with acid, be ready with lots of rosin flux and a big iron. You'll also want to clean it up when you're done. (I use rubbing alcohol and a little acid brush)

Just thought people should know...

Edit: Subject changed.

This wiring may be covered under the underhood wiring extended warranty/recall, best to check with dealer.

absolutely right, I had to pay 200 for the electrician to fix the burnt down and shorted out wiring under the battery.

Yes you right i had to change the water pump, got the whole pump at the dealer and to get th old one out andput the new one in i had to take the battery and the battery tray out..
i too had the plastic cracked off the wiring going from the positive battery post to the Power box with all the fuses in them under the hood... seems like a pretty bad job of putting wires down and the quality of the wires is pretty bad also.. and what caused it to break down??? the battery acid, dont think so, probably the heat from the engine as i notice that the contours are pretty hot under the engine compared to alot of other cars....