Your electrical ground, that is.

In particular, would you please post a picture of how the negative battery cable on your driver's side battery is connected at the battery? Is there a smaller secondary ground lead that bonds to the body, or is it just one cable to the block under the power steering pump?

I'd really appreciate this. Thanks!

 

Here you go Is this good?

 

Yes that is beautiful thank you. What year? Pre 2002? Or post?


(post, ha ha, I love puns)


By the way, I'm asking because I don't have the benefit of the original factory ground cabling on the driver's side. My year is 2000.

 

2000 F250,I'm the original owner

 

Perfect. Thank you! I've had my truck for 16 years, but I was not the original owner. It was 6 months old when I got it, and in that time, the original owner managed to change the driver's side ground (for accessories), and added a ground point to the body, on the sheet metal behind the headlight.

For years, I thought nothing of it. But now, I'm paying very close attention to ground loops, clean and dirty grounds, and the amount of resistance between sensor/signal/module grounds attached to the body and chassis, versus high current starter/charging/glowplug grounds attached to the block and battery.

I have the EVTM, but it is on a disc (from Ford, not a bootleg). A decade and a half ago, I had no trouble reading the font. Two levels of reading glasses later, not even a magnifying glass helps. I appreciate your visual confirmation of what I suspected.

I think I might need to shift my ground, and pull the body ground off of that negative battery terminal, with the goal of reducing EMI. I'm not an EE though, so if anyone else has any input, it is certainly most welcome.


Thanks again SgnAZ, for your speedy response. I know it takes time to post pics, and I really appreciate the time you took to do that.

 

2000 F-250

Passenger Side




Driver Side

 

No problem, anything I can do to help a fellow FTE brother

 

Thank you Sous. Multiple sources of confirmation! I see you replaced your battery terminal bolts and added washers on both sides. Interesting patina on the metal finish of the hardware... is that stainless?


Interesting that the small adjunct 8 gauge wire on the passenger side battery is the ONLY path to battery ground for the entire body, as far as I have had the patience to determine so far. So the PCM ground, the GEM ground, the windshield wiper motor ground, etc, all end up routing over to the passenger side fender to return to ground. On the opposing end of that cable is a similar 8 gauge wire that attaches to the passenger side frame rail.

In the process of upgrading alternators, I also wanted to upgrade the so called "big 3", which includes adding an additional grounding cable bolted to the back of the alternator. I have temporarily installed a braided strap to the frame, but I'm in the middle of rethinking that right now, to avoid ground loops, and to prevent creating alternative low resistance paths through the frame and body that high current loads to ground might seek.

 

The hardware I added is stainless. The original bolts and nuts were not working any longer. Keep us updated with how you change your grounding situation. I recently took the main grounds off the block and cleaned them very well. They were not causing problems, but preventive maintenance is key on trucks this old.

 

My thoughts on grounds: isolating the grounds that connect to electronic components from the sheet metal will not cause any problems. Some years ago I lifted some of the grounds under the dash and on the fender and connected to a wire that ran directly to the battery negative. I have not seen any problems yet. I was concerned because of the high starting amps for glow plugs and starter persuading currents to flow through the PCM, dash, and IDM grounds especially if a wire harness got chafed somewhere. I doubt that I accomplished anything by doing this.
Larry

 

What if you did accomplish something, how would you know it? I don't think you would, because success is defined as the absence of problems. And how do you make note of non events?

The G100 and G101 grounds, on the body near the firewall/cowl, have the windshield wiper motor and the PCM in the same ground zone. How often have we heard of CMP (CPS) failures and faults, leaving driver's stranded in the middle of the road way... and we probe a bit further and come to find out it happened during a light rain, and they had their intermittent wipers on. The relationship between the use of intermittent wipers and CPS failure is well known, with many examples. How does the EMI noise radiate from the windshield wiper motor all the way to the front of the engine compartment? I'm not an EE, but I do notice the common ground zone between the PCM and the WW motor at the firewall on the wiring diagram.

So if you never experience a CMP failure... could it be because of how you shifted a ground? How would you know, you know?

 

The ground loop is not common on a vehicle. A ground loop is when you have two pieces of hardware first grounded to the truck, then a separate ground path between the two pieces is made - like a shielded communication cable.

Our biggest problem with grounds is that they corrode or get loose - and that makes low current, arcing, and EMI. I was doing a routine check of my GP circuit before winter last year - starting with the ohming the grounds on each battery post (not the post clamp) to the engine block. I couldn't even make it past step one without hitting a problem - the driver-side ground post on the battery showed resistance to the engine block. At first I thought it was the clamp on the post, but ohming each contact revealed a poor driver-side cable connection to the engine block. I had to take out the ground bolt and thoroughly clean the metal on the bolt, the washers, the cable end, and the engine block with a wire wheel on my drill.

While one might think the loose ground on the driver side would not have had an impact because there are two ground connections to the block - the truth is very far from that assumption. It's true the batteries share a common positive cable, but they have only one ground for each battery. If each battery is good for 850 CCA when new, we should have 1700 CCA available to power the GPs and the starter. Lift one ground cable, and we have 850 CCA - because we have taken that one battery out of the circuit.

 

Do you think it was dissimilar metal corrosion? Or leaking power steering fluid, and the road film grime that it attracts, that seeped in between the ground cable and the block on the driver's side?

 

De-icing and any other corrosive chemicals spilled on roadways plus driving the vehicle when the roads are wet/snow covered, certainly accelerates the corrosion, which happens over time even without chemicals. I have noticed when the county uses the liquid spray (calcium chloride?) before a freezing event, there are lots of white spots on the under hood area.

Good point Rich about how easy it is to have only one battery active from corroded/loose ground. The ground behind the passenger side head is hard to access to clean.

IMHO, because of the cost of replacing a PCM, IDM, TCM, dash module, stereo, nav, engine monitor all the grounds for sensitive circuitry deserve a complete copper circuit. Sheet steel/frame bolted together with potentially rusting bolts does not deliver the long term proper operating voltage for these necessary components.

 

A little late to the show, but here's mine.