Negative wire

Is it possible to find a good spot to connect negative wire for additional electrical devices in the back of the truck?

I know that the cabin is directly connected to the negative pole on battery. But what about frame and rear fenders?

My concern is that I don't see any connection points for factory devices like rear lights. I see that they connected to set of wires(positive and negative) and it is not connected to the fender.

 

Everything is grounded to the frame. Just find a good spot on the frame for your ground and you will be good. Be sure to remove paint/coating so your ground is metal to metal. Repaint over the ground to cover and exposed metal.

 

I just screw a self tapping pan head screw with a terminal on it to the frame

 

I doubt a self tapping screw will go through 1/8" steel. It may though. I drilled a hole in my frame, sanded down the paint and used a nut and bolt for my ground. Then repaint bare metal.

 

I mean, you can doubt all you want but that's what I've been doing

 

I guess I stand corrected. I would have thought the self tapping screws would not fare so we'll against a steel frame.

 

if it was a strong steel maybe lol.

But the frame isn't that thick self drilling screws should work fine. But personally I think the nut and bolt idea is stronger.

I'm just thinking from work aspect when we do bonding of anything metal in electrical rooms or the main structure, we always try to nut and bolt, then pein the ends.
Where we can't like door frames we usually drill and tap.

By code can't technically use a self drilling screw unless its one of those ones that have the little teeth under the screw head like Tek screws to help lock it, but even then inspectors don't like seeing it.

I personally bring everything back to my negative block of my aux fuse panel. Uses more wire and is more work yes, but its a solid connection and just what I'm used to from work.

 

Wait - don’t use the frame to ground heavy loads (lights, fridge, winch, etc.) because you could cause ground offsets where your high amp device grounds through yoir smaller devices, or other transient voltage issues with sensitive electronics.

 

This.

 

very reason I run a dedicated line.

 

Look under the driver side rear wheel well. There is a ground on the top of the frame.

 

Frame is always best for ground, but if ground wire is needed. Most WHITE/BLACK wires will work. Toyota has been using WHT/BLK for years now.

 

I'm building separate point of distribution inside the shell(with separate fuse box, switch and relay unit), so, I need high amp ground. The positive wire is already set up from the battery in a separate wire channel. Will try driver side on the frame for negative. I don't know why I did not make separate negative wire from battery. From small cars world I remember that it's always possible to find ground on the body.

 

i'd buy some more cable and just do a dedicated run to the battery.

 

Define "high amp"...

 

Where does everything centrally ground to? Battery and engine block ground to frame. All electronics ground to the frame. Some not directly but through one wire loom or another, the frame is the central ground point.

Unless something has changed in recent years, this is how it's always been done.

 

Not necessary. That adds more work, money, and more places for there to be a potential electrical failure due to more unnecessary wires.

 

how does that add more locations? if anything it limits failure as its not on the frame to pick up a negative where it can corrode vs being in the engine bay on the battery?


More work and money ok but in no way would it be more places to fail. If anything its less likely to fail.
Run the wire properly it shouldn't get damaged and then you have two places to look if something doesnt work. end at use or end at source. and neither ends should get lots of exposure to the elements where they will corrode away.

You're better off having a negative bus that runs back to the battery with a decent size wire then take all your negative loads at the rear off that.

 

it depends on the load.

steel does not have the same current carrying properties as say copper. frame might work for small lights but anything big its better to go straight to a negative block.

 

It adds more points to failure because there's always the possibility that the wire can get pinched, corroded, torn, cut on something, etc. Also, the longer the wire the thicker the wire needs to be depending on the load.

I have been an aircraft mechanic for over 15 years and have taken two years of aerospace engineering classes with some pretty good electrical engineering classes in there. I hardly know everything when it comes to electrical but in my experience and knowledge, longer wires are never a good thing when the same can be accomplished with a local source. Please, if you can prove what you're saying or if your experience says otherwise then post up some evidence.