Factory Ground Point Question

So Ive been in the process of installing two amps under the rear seat of my Crewmax and would like to know your expert and even not so expert opinions/facts on grounding an amp.

I have been searching the web for the last couple of weeks trying to determine the best, but least invasive way to ground my amps. Ive seen people ground by tapping into the floor near the bottle jack, using seatbelt bolts and seat bolts.

I would really prefer not to use the seat or seatbelt bolts and im not all that excited about a hole in the floor. I will do that if I truly need to though. If you have any other suggestions for a clean ground, I would greatly appreciate it. And...

... has anyone used the factory ground points behind the rear seatbelt panels? Would these provide a good ground? I did this and have yet to connect the amp before I decide if I have grounded in a place that is sufficient. My ground is the 4 gauge red wire, I know, I probably should have used black or dark wire. for my other amp, I have it connected to the other sides factory ground point. Here is the spot Im talking about:

 

The only thing I would ask would be is that a sheet metal screw, or a bolt that goes into a captured nut on the back side. I have found over the years of installing amps that sheet metal screws do not work the best, as they not only have a tendency to vibrate loose, causing static/increase in "alternator whine", and that they do not make as solid of a contact point for surface area. Captured nuts are best, but I always clean off ALL paint, primer, or metal protectant chemicals first. Then I will spray a protectant like a bedliner spray over the top after tightening the bolt down.

 

Yep it's a 4 gauge wire. I've got 1/0 running to a distribution block to 4g.

Bama, is there a way I can check with my multimeter that its a good ground? Haven't done an install since I was young and definitely never researched what I needed to do back then. If I have no noise and speakers play perfectly, can I assume the ground was good?

 

You can do a voltage drop check. Using a multimeter set to voltage, measure the voltage between the ground terminal at the amp, and the battery. You SHOULD see less than .3 volts for that large of an distance. If it is too high, then break it down into smaller sections and measure each to see where the highest voltage drop is. Once you find that, you will know where the weak link is.

 

Hey thanks man. Appreciate it!

 

by the way, my rear speakers and amp are in and they sound perfect. No noise other than the music!

 

That is good to know! Means you have everything grounded and connected properly!

 

Well, I was getting a slight static, almost undetectable, while music played. So I decided to change my ground points. I used a 3/8 bolt with washers and a locking washer thru the floor underneath the back seat and below the hard foam there. Afterwards I siliconed both sides, and used a rubber spray under the truck. I think it's worked to clear it up, but I also tweaked the gains on my amps again, so ill have to verify when my hearing is fresh.

 

Glad to hear that you are getting it sounding clearer. If you have any other issues or questions, feel free to ask. I do this stuff all the time. I am still fighting a grounding issue with my HID headlights that drives me nuts! I turn on my headlights and I loose reception range on the radio. It doesn't create noise or anything at all, just the range of the radio reception goes down. Only reason I ever noticed it was that I live in a rural area, and we have problems enough with good signal from my favorite stations.

 

No kidding, that's frustrating. Could you run ground directly to your frame?

Well, I think moving the ground helped, but I also think the factory head unit isn't the greatest.

So I moved the ground for both amps to under the rear passenger seat, 5 inches from the furthest rear seat bolt, under the hard foam beneath the carpet... Just realized I posted that part above... Oh we'll. my question is, is this a fire hazard? I didn't think so at first, but began wondering if I put it in a bad spot.

 

I would suggest against grounding to the frame. The battery grounds to the engine block, and the body. There is insufficient grounding to the frame in general for high-current items like amplifiers.

Grounding to where you did is not a fire hazard, as long as the bolt is well secured, and the cable and terminal are solid, and of the correct size. I recommend using a minimum of a 4 gauge cable for grounding.

 

Ok, thank you. I used gauge wire. Ive got the whole right side of the dash torn apart right now, installing a new head unit and the Idatalink for my steering wheel controls. The stock head unit just didn't put out a very clean signal. Sure will be glad when im done with this.

 

My tundra did this when i had my old Hid lights in.. I found out the ballast are not shielded(cheap ones) and the noise they put out is enough to over ride the tuner in your radio.

When i did i upgrade to my headlights and fog lights i went to TRS. Using there ballast for fogs and running toyota denso ballast for headlights i have no radio problems at all. The wiring for the old system and the new system was the same and used the same ground points..

 

Alas, it was a shitty ground, compliments of cartoys (Boulder, CO.). Took off ground, sanded frame (which wasn’t done in the first place), replaced nut/bolt with new and now both batts are testing at 13.5v when truck is on and I’m guessing this is gonna fix the noise that’s been coming thru my 10” sub. Thanks for all your help guys.