Originally Posted by heavyhaulerss (Post 422486)

this is very informative. after putting my truck in 2 shops a while back & not 1 of them could find
why my truck was trying to shut down(engine stop light come on) it would shake, sputter then be o.k. for a while. I looked at all the cable ends. they all looked good. I replaced all cables. ALL OF THEM. no problem since. looking at just the ends was not good enough in my case. there was corrosion beyond & under the ends, & coatings. after putting my truck on the comp, it showed all kinds of codes, like oil press @ 12 lbs, water temp too high. wich none of there were true. i knew then it had to be something electrical to show things were happening, when they indeed they were not. after 8 days in the shop, a few hundred dollars & a couple grand lost in revenue. i fixed myself by replacing, ground to batt & frame, hot from starter & batt, & all jumpers, & new ecm wire. though I sure learned something. oh & i also replaced hot & ground on alt. it cost me 2 hours & about 200.00 something that 2 shops & 8 days could not do.

Originally Posted by Musicman (Post 422740)

I’ve found that using sealed batteries, such as Optimas or others is the best way to stop corrosion at the battery. I used black frame paint to coat the ground connection to the frame.

Originally Posted by Kranky (Post 422767)

One liberal application and it's done.

Originally Posted by Orangetxguy (Post 422479)

:hellno::hellno::hellno::hellno::hellno::hellno::h ellno::hellno::hellno:


Ooooooooh Gary! Oh deer! Deer deer deer !!!


You is mis-informed on who makes your twuck!

Spreaken-ze-deutch!

The company that owns the manufacturer of your fine piece of "Used to be American" twuck......Is DiamlerBenz!!! They just did away with their Sterling (re;Ford twuck line). :cool::cool::cool::cool:

:lol::lol::lol::lol::lol::lol::lol::lol:

Time for you to get some beauty sleep...so you may ponder these informative lessonz.
:zzz::zzz::zzz::zzz::zzz::zzz::zzz:

Originally Posted by Doghouse (Post 422851)

I used liquid tire bead sealer on my grounds when I put my truck back together. I put new grounds from the engine to the frame, from the cab to the frame, sleeper to frame, batteries to the frame. Then ran all new wire from the batteries to the starter, and the computer to the batteries. So far no problems with the electrical system. I used my inverter for 5 days before my battery bank fell to 12.5volts,....I watch too much TV me thinks.

Originally Posted by Musicman (Post 422124)

Since we bought our new truck, I’ve been battling some mysterious problems. One is an intermittent cruise problem I’ve already posted about in this forum. Another one is a problem burning out headlights and associated harness connectors. All battery connections are tight and I’ve looked at just about every other possibility. A few months ago, I was in Whittier, CA and spent about eight hours with Tyler Stone, the owner of Comfortmaster APU, and one of the things he mentioned when we were talking about trucks in general is how surprised he was at how poorly most truck electrical systems are designed. He commented that the battery cables with the huge insulated ends (over the connectors) are garbage because the insulation on the connectors limits contact between jumpers (between batteries) and battery cables and the battery posts, and that he’s never seen a truck that was properly grounded from the factory. Tyler and Comfortmaster are only recent entrants into the APU market. For the last twenty years or more, his companies have provided custom built generators to the movie industry, department of defense and others, so when it comes to issues involving electrical power I value his opinion.

This week, I finally got a chance to really work on our truck and it’s amazing what I found. The starter has only one 2 or 0 gauge ground wire going to the frame and the same thing applies to the batteries. What is even worse is the way they are attached to the frame. Peterbilt drilled a hole through the painted frame, put a 3 inch bolt through it, and put two washers and a nut on the bolt, then the ground and then another set of washers and a nut. The result of this is that the ground wire connector makes no bare metal to bare metal contact directly with the frame, but rather must rely solely on its contact with the bolt and nuts to conduct current. Direct Current electricity travels on the outside of surfaces, not through them, so the idea is to have as much surface area in contact between connections as possible. Peterbilt seems not to understand this.

I removed the starter ground from its frame mount bolt, took the nuts and washers off the bolt, ground off the paint surrounding the bolt hole and then bolted the ground connecter directly to the exposed frame. I also added an additional 0 gauge battery ground to the same bolt. The result was that the starter spins the engine more easily, all of my lights (especially headlights) are brighter, the charging system seems to be working more efficiently (volts gauge used to put out just above 13.5 volts, now it’s putting out 14.2), and I was able to idle the truck up with the cruise without it kicking out after a few seconds, which has always been a problem.

My last Peterbilt would go through a starter about every 18 months to 2 years. It makes me wonder now if part of its short life span was due to having an inadequate ground. I won’t know for certain if this solved my headlight and cruise problem until I get out on the road and put some hours on the truck, but things are definitely looking up.

Even if you aren’t having any electrical problems, it might be worth your time to check how well grounded your truck really is. It might save some problems and money down the road.