Sorry for the new thread, but it really didn't fit with any of my previous ones.

I have read in several threads that it is best not to ground an amp to the seat belt bolts because you will get an intermittent ground. I am installing my amp behind the rear seat in my 05 Supercrew and need to know where would be the best location to run the ground. I plan on running 8 gauge from one amp and 4 gauge from the other to a ground distribution block, then grounding with 1/0. I just don't want to get stuck with a bad ground once I get everything installed.

I did a search and couldn't find a post where this was covered, so if one is available you can just point me in the right direction.

 

I went to the seat bolt on mine.

Just scuff up the paint around where the head of the wire is. Metal to metal will conduct just fine.

There should be atleast 2 major body strap grounds going from the cab to the frame under your truck.

 

I drilled a hole in the seat belt frame. Ran a bolt thru it and it seems to work fine. no paint to scrape off either.

 

I wouldnt feel comfortable drilling through a saftey device support on the truck. But that is just me.

 

ha, true. It's a 1/4" hole in 3 gauge steel. It will be fine. That is unless I drive off the Hover Dam. But that would be the last thing i'd worry about.

 

I did the Big 3 by adding and additional cable on the following:
1. Alternator to Battery
2. Battery to Engine Block
3. Engine Block to Chassis

I noticed the braided ground strap from the chassis to the body, but did not do anything with this. In only noticed one, but wasn't really looking either. Should I add cable to this connection also? Additionally, there is a small (looks to be 8 gauge) wire from the negative battery cable to the firewall. I assumed it was not necessary to add anything to this either, but figured I'd ask.

 

If you want to do more of the larger cable to the body, dont remove the stock one, but simply add to it.
The stock braided cable is actually has a secondary purpose of a saftey system incase of a major roll over collision.

 

I know i couldn't hurt to add larger cable, but it is going to be of any benefit? Won't the seat bolt be in contact with the frame anyway? If it is going to help I want to do it, but I don't want to do it just for fun.

 

seat bolts to the body

body bolts to frame

probably wont help you anymore by doing it

 

I haven't looked, but I just assumed that the seat bolts went through the body into the frame. I guess you learn somthing new every day.

I guess I will just finish my install and if I have any issues then I can add an extra cable on the chassis to body strap and see if it makes a difference.

 

The best way to find out if its a good ground or not is to check resistance between the proposed ground and the battery. Seat bolts and body panels can be notoriously bad grounds, as logical as they may seem. Spot welds, glued together body panels, and other factors lead to very high resistance between the grounding spot and the battery. You've already hit one of the most important aspects of a quality install by doing the big 3. Heres what you do to check your ground.

1) Get a length of 8 or 6 AWG long enough to reach the battery (as an "extended lead") and check resistance of said wire with a DMM. Remember this number as it will be important to you very soon.

2) Attach the "extended lead" to the negative terminal on the battery. Now touch one lead of your DMM to the proposed ground and the other to the end of your 8AWG. Subtract that number from step one and that is your total resistance. If its a good ground it will be less than 1 ohm.

Thats all you need to do to check if the ground in question is a good ground. Hope this helps.

 

Thanks so much for the way to check. Since I have a DMM in my toolbox I will be sure to check before selecting a grounding point for the amps.

 

Like this? -

 

WHAT IS THAT???

 

haha...I was wondering that myself, just didnt wanna say anything.