I can offer a few suggestions. If you can find a spot to drill a small hole, make it big enough so the terminal can be pulled through too along with the wire. Most under-hood fuse boxes on vehicles as new as yours include electronics or a computer module in addition to fuses and relays. As such, and much due to the environment they live in, failures are common. If you need to replace yours, you can pull the wire out without having to cut the terminal off. Once the project is finished, seal the hole with a thin coating of RTV gasket sealer. There are many good products available, but I'm only familiar with two from the Chrysler dealer's parts department. They have a gray sealant that cures fairly hard and it is harder to remove later. It's huge advantage is it will bond and seal through a light film of oil, such as occurs often on transmission pan surfaces. For your purpose, their black sealant is a better choice. It will not seal through a film of oil, but that isn't a concern here. It remains more rubbery and will be easier to remove.
Of bigger concern in my world of electrical repair is adding terminals alongside a fuse. GM has been well-known for having fuse and relay socket terminals that become weak and cause intermittent connections. Adding a side-by-side terminal will spread those terminals on any car brand or model. There is a very good chance this won't be a problem for you, until that terminal is removed, then it will leave you with a weak connection. You may have to leave the extra terminal in place and just cut the wire off if you want to remove the accessory.
I help a friend with electrical issues at his body / repair shop, and run into this a few times per year. He knows I won't let him use these add-on terminals, I insist all splices must be soldered, and I don't allow electrical tape on cars and trucks as it will unravel into a gooey mess on a hot day. Instead, we go the bottom of the fuse box and find a wire to splice into, then we seal it with moisture-proof heat-shrink tubing. There's usually a half dozen very large connectors under the fuse box, so you just unplug them if you need to replace the box. No need to remove add-on terminals or drill holes.
GM also used to be famous for providing accessory terminals in their fuse boxes. You might look for those first inside the vehicle. If you find one labelled "ACC", that turns on and off with the ignition switch. If you need one that stays hot all the time, look for one labelled, "B+". If they still provide those, they are single terminals, not doubles like fuses need.
Be aware too that if you do run into a stretched fuse or relay terminal, while it can be a very time-consuming, tedious job, you can usually remove the terminal, but it's almost impossible to bend them tighter. Instead, the dealer's parts department has large terminal replacement kits that include every style of terminal used for every connector or socket. That is a better alternative to having to replace the entire fuse box or connector.
I ran into this on a newer Ram truck where the owner stuffed a test light probe into the terminal, (something else I don't allow). That spread the terminal so badly that the fuse could not be made to make a solid connection. On that one, I took the box apart and found there was no electronics in it, but it had six layers of plastic boards with metal strips embedded in them stacked on top of each other. Those metal strips popped up and turned into the fuse and relay socket terminals, and as luck would have it, once exposed, they were easily able to be bent back into shape. GM and Chrysler do a lot of stuff the same way, so don't panic if you do run into a problem related to those terminals. We will be able to figure out a way to repair them.
You also have to look at how much current your accessory draws. A vehicle circuit that could draw up to seven amps, for example, might be protected by only a ten-amp fuse. Similarly, some people try to add fog lights and power them through a headlight fuse. Those usually don't have enough safety margin to handle another bulb. If you run into that, it's better to use the vehicle's circuit to run a relay. A relay's coil draws very little current. Most GM and the 1"-cube Chrysler relays can handle 20 amps, and there are some that can pass up to 30 amps. If you want to pursue that, I can help you come up with a circuit, if necessary.
Finally, mostly for the benefit of others researching this topic, I should mention it is never acceptable to stuff a wire under one of the battery cables when you have side-post batteries. Also, those little 5/16"-head bolts are not designed to handle the high current of jumper cables or wheel-type battery chargers. They will work for small portable chargers, but the very high-current starter circuit current flows through the contact between the cable end and the battery post. That connection must not be compromised by sandwiching in a wire. It will hold part of the connection apart and lead to the small remaining section overheating and burning away. The better solution is just about all battery cables have two wires molded into each cable clamp. For the positive side, the fat cable goes to the starter, and the smaller one typically bolts to the under-hood fuse box. That fuse box connection is already an extremely common source of trouble on all car brands. The nuts work loose causing intermittent problems, commonly the dash goes dark as soon as you try to crank the engine. That is still the better place to add an accessory terminal. You'll likely end up with that nut tighter than it was before.
Saturday, January 4th, 2025 AT 11:10 PM
