Ground the Grounds?

[JayTheCPA]

What are thoughts toward running a dedicated ground line from each of the common grounding points back to the negative post on one of the batteries?


Example: Add a wire from the rear passenger head (where a bunch of lines ground to the head) to passenger side battery so that the end result is that all the misc lines remain in place and I add a new line that then ties that location direct to the battery post. Ditto for any other grounding location.


If grounding the ground locations seems reasonable, thoughts toward wire size (14, 12, or . . .)?

Also, if a good idea, which battery makes most sense?


Or was this thought already discussed asked and I missed the thread?

 

[FellowTraveler]

When I did my wiring I had increased wire gauge on the positive then added heavier grounds from battery, body and chassis. The body is a very large grounding plate already and adding additional or even larger grounding cable will be fine.

 

[Burning oil]

I use 4ga bat cable to frame on same stud on intake for bat ground. Then from engine to cab too.

 

[WarWagon]

There is a downside to doing this. IMO just stick with a big three type of ground upgrade. Frame/body/engine. (IMO a additional ground off the blower motor to the body is worth doing.)

Adding grounds from existing grounds to the batteries is a waste and has a few downsides. First the engine block doesn't have much resistance so the wires don't help much. The small gauge wires can literally flash fire on you if a battery ground comes loose on the engine and you try and start it. Last, noise: the extra wires run from grounds can transmit noise specifically alternator hum to the radio/onstar. Some trucks like a 2002 Silverado with the 5.3 V8 have a different alternator sense location because the factory location causes shift hunting in the ECM due to induced noise, feedback, whatever.

I have found you want to strap down the big three grounding wires at unused bolts on the engine, frame, and body. Adding a big three cable to existing in use OEM ground bolts on the body adds to the alternator noise on a few GM rides I tried it on.

 

[ditchpig]

Always hearing about bad grounds, redid mine +8 years ago because of issues (broken braided straps) and no problems since. Up here in the rust belt with salt & brine being put down on the roads in winter it takes its toll.

Added 2awg fine strand wires for flexibility with crimped & soldered lugs (or crimp with conductive grease) for batteries to frame, batteries to engine, engine to alternator (should have a treaded hole on back or use case bolt), engine to fire wall (cab), engine through fire wall to tube under dash, frame to box. Yes that's 8 in total.

All ground connections clean to bare metal & I use a conductive grease Noalox or Loctite Graphite anti-seize & then sprayed with undercoating oil after tightening.

http://www.loctite.com.au/3320_AUE_H...=8803871981569

http://www.idealindustries.ca/produc...ies/noalox.php

Hopefully this helps anyone having grounding issues.

 

[jrsavoie]

I used 10 ga and added all the grounds I have posted about before.
To the ground stud at the back of the engine - I've seen that stud loose connectivity to the block before, To the frame, to the battery box to replace the wimpy screw in the fender, to the dash mount bolt from the heater blower, to the ground screw on the IP and to the remote heat sink for the PMD

 

[ditchpig]

Make good grounds that don't corrode. The low ohms tester I use goes to 0.000 ohms, I look for 0.250 or better. And yes all the ones jrsavoie added aswell.

 

[Steve83]

What you're actually doing is "UN-grounding". The first electric circuits were for lighting city streets. Copper wire was new, rare, & expensive, so Tesla realized he could use THE GROUND as a conductor, and only run 1 insulated wire from the generator to the lights. The ground was the return conductor. That practise was continued almost universally (including on vehicles, using their metal chassis as "the ground") until circuits became too delicate to rely on something as unpredictable as dirt or fasteners.

Since the aging "ground" connections on these trucks are becoming less-reliable, and the cost of wire has come down so drastically, adding a true return wire (bypassing the ground) makes a lot of sense.

The best way to do it is to use 1 continuous heavy wire (like ~30' of welding cable) to join all the chassis & body grounds directly to the battery (-) terminal. Strip & bend the wire to add ring terminals, instead of cutting & splicing. Each splice creates a potential problem, just like the ones you're trying to get rid of. This shows what I mean:



When I built my Bronco, I embedded a new return wire in the engine bay harness.