I have read a few posts lately by people that have replaced their batteries and now are having other electrical problems. I thought that I would dish out my two pennies worth of info on the situation. If you replace your battery and/or alternator, the grounds need to be cleaned. This means the ground to the engine, body, and frame. When a battery gets weak it puts a strain on the electrical system. This is when you start to see corrosion. You install the new battery and the excess voltage has no way of returning to the battery bacause the grounds are corroded. This excess voltage will find the path of least resistance, meaning that it may start causing false idiot lights, disrupting the radio, sensors failing, and even tranny shifting problems. The layman term for this is stray voltage.

 

I disagree with your explanation. Corrosion in the ground connections causes ground shifts, which causes the supply voltage to be low to electronic components.

 

I don't disagree with that, but I have seen many times were the voltage has caused a failed sensor/sensors after the battery was replaced. I had a 00 Taurus which I replaced the battery and started to have radio problems, cyl. 5 misfire, and egr codes. I did this at home and did not have access to all my tools. When I got to work and had a spare minute, I cleaned all of the grounds and put a ground strap from the tranny bell to the top of strut tower. Problems all disappeared.

 

You old battery was more than likely good and you had ground problems all along. If you cleaned them first you would not have had to change the battery.
By the way the frame on most trucks is not grounded, I have not seen a ground wire ran to the frame in any of the truck diagrams. The motor is insulated from the frame by motor mounts and body has rubber mounts to the frame.
Most of the time the frame is at ground but do not count on it being ground.

 

The frame would get tied to ground through the drivetrain.

 

What part of the drivetrain is ground to the frame?

 

The battery in the Taurus totally failed. Went to work one day and that night went to leave and the car would not start. Battery would not hold a charge. I know GM trucks do have grounds to the frame, they go from the block to the frame at the back of the engine. When ever we replace or rebuild a tranny at work we add a ground from the bell to the frame, usually near the starter.

 

The diff(s) through the springs....

 

You are kidding right.
Are you saying the frame is grounded through the drive shaft, U-joints, slip yokes, leaf springs with their rubber bushings and shackles and this is a good reliable ground?

 

There is metal to metal all the way......check it out.Your question was how is it grounded, I told you how....now you add reliable and good...

 

I was talking about "fordfaninIL." post above when he said "If you replace your battery and/or alternator, the grounds need to be cleaned. This means the ground to the engine, body, and frame."

 

Hey guys, I'm just trying to make the point that when you change the battery or alternator you should clean the grounds to prevent other electrical problems as a result.

 

There are several points being discussed in this thread. The first is what could possibly cause a battery to fail, and the second I see is how a factory electrical system is grounded. I would like to comment on the grounding method.

The factory does have ground straps from the engine block to the body. I am not sure about the frame, but I would think it would get one somewhere. We are talking small gauge grounding wire here, not the large 4 and 6 gauge wire for the starter.

These small grounds are very important, and can cause serious problems if they are left off during an engine change, or jerked in two by a body lift. There have been several posts throughout the years where a vehicle flat would not work, or would have mysterious problems because the small ground straps were missing. I bring this up because this confirms there is no grounding naturally through the drivetrain to the body or the frame.

The large ground from the battery is usually bolted to the engine block. This is because the starter motor is bolted to the engine/bellhousing, and is the largest amperage user of the electrical system.

To give us a quiet smooth ride, the engine is mounted in rubber motor mounts. The tranny and transfer case is also mounted in rubber mounts. The rear springs are mounted in rubber bushings. The shocks also have rubber bushings. Even if the frame was somehow grounded from the drivetrain, the body would still be isolated because of the rubber body mounts.

All of these bushing/mounts are the molded rubber type, where the mounting studs/bolts are totally incased in rubber.

So I have to agree, there is no natural grounding through the frame, body, or the drivetrain, unless a conductor is purposely attached from one to another.

 

This post had some good info on checking grounds but whoever thought the frame is not grounded is in left field.
If it wasn't then the directions for jumper cables from many sources (manufacturers of them and cars as well) are wrong. Ever read the part where they say dont let bumpers contact or to ground them to the frame otr other metal area?
Everyone seemed to leave out the fact the trans is hooked to the motor, ( it is not made of rubber or plastic give a hint shiny stuff), then it off to the drive shaft (made of more shiny stuff but rusts)where it attaches the rear end and springs ( really heavy rusty shiny stuff) all of which is in way or another connected to the frame, then yes there is a ground to the frame. Let alone the fact that the steering column which attaches to the metal under the dash ( of a already grounded cab) and runs to the steering gear box and attaches on the frame by bolts.

That and yes there are rubber mounts for the body but the hole the bolt goes thru and tightens down to are yep you guessed it metal there is only rubber in between the threads not at the head of nut end of the cab mounts or the frame. Unless they are using plastic/ rubber/wood/ you get the idea non- conductive bolts so yes there is a ground.
Where did you people ever get an idea the frame is not grounded? A Steven Spielberg novel. You know a mystery novel.

 

If you would have read this post you would know how far off in left field your post is.
Some trucks do have a push on ground strap from the frame to the body but I would not trust this for ground. There is no bolt on ground cables (wires) from battery ground to the frame.
Every thing you mentioned is not a good source of ground.