Should there be a grounding strap from the engine to the body?

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gilberttitan08 said:
No, it's all bonded from the battery to the engine from engine to body, nothing wrong with adding a ground strap.
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RustyRatRod said:
Say WHAT?!?!
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pishta said:
Yes, batt negative to block, then block-head to chassis. It didnt look right at first but i think he was trying to say this. Mines off pass head rear to blower bolt with star washer under both, other one is rear intake bolt To same firewall area.
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I think what Rusty was saying, LOL is the way this is worded it implies no extra ground is needed.

The engine is NOT grounded to the body / chassis unless you make it so.

I guess you could "claim" that on auto cars the two original trans cooler tubes ground the engine / trans, but THAT is a STRETCH

You need the engine, the body, and the battery NEG all same

If you have a car with a chassis (Dodge pickups and a few Mopar cars) you need to bond the frame as well.

Those rusty bolts in the K member are NOT grounds!!!
 
Get one of these wire bonding brushes from Yardstore.com. It will clean to bare metal in a nice round circle and look much nicer than an area scratched bald. Spray the connection with LPS-3 and the ground path may outlive you.
 

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On anything that isn't a show car, I also like to add a ground from the engine to one of the ECU bolts, just because I once had intermittent grounding issues with an ECU that drove me insane for weeks.
 
crackedback said:
I always run multiple grounds to the engine, battery and chassis.

I've seen cars use the speedo cable as a ground path, melting the casing from end to end.

Good grounds are essential to electrical component performance. Slow cranking cars are lots of times a grounding issue.
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Absolutely! I was just thinking the same thing as I was reading the posts. I've seen throttle cables catch fire & burn a nice car into a charred shell because that was the only ground the electricity could find.
 
Lonewolf3165 said:
Absolutely! I was just thinking the same thing as I was reading the posts. I've seen throttle cables catch fire & burn a nice car into a charred shell because that was the only ground the electricity could find.
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My first Honda smoked its speedo cable, wonder why> ;-)

every trailer queen Mopar pic from the 70's had a ground strap/cable off the passenger intake bolt to firewall right above it or very close..
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pishta said:
Yes, batt negative to block, then block-head to chassis. It didnt look right at first but i think he was trying to say this. Mines off pass head rear to blower bolt with star washer under both, other one is rear intake bolt To same firewall area.
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Much the same here. Dart Custom /6, batt to block, then back of head to firewall. Demon was originally a /6 car, batt to drvr side head, then pax side head to firewall.
 
you can never have too many grounds.
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When you run into the issues that a Ground Loop (<-wiki link) creates you'll think differently. Those can make you crazy! BT, DT; they didn't have the t-shirt!

Route the grounds sequentially only, never create a looped ground path.
So: battery to engine, engine to body. Do not add battery to body.
Or: battery to engine, battery to body. Do not add engine to body.

The flat braided straps make better grounds than does cable. If they are big enough they will conduct high current DC (starting current), but any of them will also conduct RFI better than a cable will. Don't really know why, I think that I understand it minimally, but not well enough to explain it. I do know that when I worked at the R&D dyno facility that the MSEE in charge of all of the electronics insisted on flat braid for the grounding straps.
 
Lonewolf3165 said:
Absolutely! I was just thinking the same thing as I was reading the posts. I've seen throttle cables catch fire & burn a nice car into a charred shell because that was the only ground the electricity could find.
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I don't have a grounding strap but after reading all these posts I am definitely getting one before my next drive. Sounds like no reason not to have one and lots to.
 
Route the grounds sequentially only, never create a looped ground path.
So: battery to engine, engine to body. Do not add battery to body.
Or: battery to engine, battery to body. Do not add engine to body.
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That's interesting. My late 72 built 73 Challenger uses a negative cable with two wires on it. One wire goes to the DS head, the other goes to the rad support. Later on in 73, the factory added an additional ground wire from the back of the PS head to the firewall. The two ground wires coming off the battery stayed the same. Your quote says not to do that.
 
A TON of cars came from the factory with grounds right off the negative terminal straight to the fender well, radiator support or inside the fender, plus the main ground going to the body. Isn't that what you describe? They worked just fine.


ntsqd said:
When you run into the issues that a Ground Loop (<-wiki link) creates you'll think differently. Those can make you crazy! BT, DT; they didn't have the t-shirt!

Route the grounds sequentially only, never create a looped ground path.
So: battery to engine, engine to body. Do not add battery to body.
Or: battery to engine, battery to body. Do not add engine to body.

The flat braided straps make better grounds than does cable. If they are big enough they will conduct high current DC (starting current), but any of them will also conduct RFI better than a cable will. Don't really know why, I think that I understand it minimally, but not well enough to explain it. I do know that when I worked at the R&D dyno facility that the MSEE in charge of all of the electronics insisted on flat braid for the grounding straps.
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If you have noise in the stereo that you can't make go away or if some of the electronics that you've added to the car (that weren't there OE) misbehave or flat don't work on occasion it's likely the fault of a ground loop. Have to keep in mind that how it was built back then did not include modern electronics, and those are susceptible to noise from ground loops. Instead of looking how it was done back then, look at how it is done now on modern vehicles.

If it's a true restoration, then how it was done then is absolutely how it needs to be done.

If not, then how it's done now is more relevant.
 
RustyRatRod said:
A TON of cars came from the factory with grounds right off the negative terminal straight to the fender well, radiator support or inside the fender, plus the main ground going to the body. Isn't that what you describe? They worked just fine.
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Yeh. And you'll find that NONE of those came with any EFI or any other critical electronics. What he speaks of is a REAL issue. Audio guys (working with line levels and microphone mixers) run into this, as does anybody who works with instrumentation.

This is getting to be an issue "for us." I run Holley EFI, so it obviously lacks the years of time and millions of dollars that the OEMs spent doing R & D.

"Back when" I was in auto parts there was a "rage" to put pyrometers on diesel trucks. I can think of no worse example of poor grounding, than a logging truck.........dirty, rusty, everything moves whether it's supposed to or not, and back in those days, some of them ran starting relays which started on 24V and ran on 12. Pyrometers are essentially "self powered" by the thermocouple. Was it any surprize 'we' had trouble?

When I worked for Motorola, we had a big issue with an old surplus truck "brush rig." This is a short wheelbase, military fire truck all wheel drive, built to "get out" into the brush. It was so noisy, it had aircraft style "ear muff" headsets so people could hear the radio. A ground loop problem caused noise, static, and alternator whine in the radio.
 
IIRC, a lot of the ground wires to the rad core area were for grounding things like the turn signals, horn and relay, etc.
If I am not mistaken, in a DC current set up, power typically flows from NEGATIVE to POSITIVE, not the other way round. So your ground wires actually are the ones that supply juice to your components and the positive leads return it to the battery.
How many guys have left out that little jumper wire between the steering column stud and the side of the column, and then wondered why their turn signals or key switch did not work? Ever wondered why those small self tapping bolts that hold down the starter relay or the voltage regulator or horns have little teeth that seem to cut into the metal? Or the nuts that hold the column up on those studs? All to make grounds for those components.
 
Let me see if I can make things confusing by giving bad information.
I think there is a difference in terminology, and hence purpose.
There are bonding straps and ground(ing) cables/wires.
(We will ignore neutral conductors as NA here)
The way I understand things, one the purposes of a bonding strap is to prevent ground loops.
In other words to ensure all the big parts of the car are at the same potential.
If the negative parts of a circuit are not at the same potential with other items that are "grounded" to same place (Ideally R=0) then there is a problem.
A bonding strap is there to ensure that does not happen.
Otherwise one could and probably does have little ground loops everywhere on a car.
PANIC NOW! YOUR KICK DOWN IS CONDUCTING SOME JUICTRICTY!
 
airgrabber said:
in a DC current set up, power typically flows from NEGATIVE to POSITIVE, not the other way round. .
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The direction "current" flows is irrelevant. It could go in either direction, hell it could be an AC system and the grounding, which is simply "the other conductor" would work the same

adriver said:
There are bonding straps and ground(ing) cables/wires.

The way I understand things, one the purposes of a bonding strap is to prevent ground loops.
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It really cannot be separated from some "magic" bonding strap to do one thing, and another conductor to do another. In an ideal situation, you would have ONE ground point........in this case the battery NEG terminal.

Maybe a better example is wooden boats?

The fact is, that many earlier cars were "damn poor." There is almost NO ground connection between the [ engine block / battery / battery neg cable ] as a "group" and the body / frame in many earlier cars.

This became instantly evident when guys started putting electric "wenches" on their vehicles...and burned up the no12 ground wire from the body to the battery.
 
I run a common spliced & soldered ground wire from my neg battery post to the firewall, passenger side head, voltage regulator mounting screw and ECM box mounting screw. The neg battery terminal main is grounded to the block. I also run a seperate ground wire from my alternator to my block. Never any issues.
 
desmo900 said:
So what is the proper grounding sequence if we are running aftermarket EFI?
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I would start by reading, reading, and then CAREFULLY reading the EFI kit destructions. Holley has a tech forum if it happens to e one of those
 
Bonding and ground loops are distinctly different things that are inter-related. Bonding isn't to prevent ground loops, can create them if done wrong. Grounding/bonding needs to be done like how a tree branches. A ground loop is exactly that, a loop. If you can trace two or more unique paths to ground from ANY place on the car (that isn't insulated conductor) you have a ground loop. Think about the tree, start anywhere on it and head towards the roots. There is only one unique path possible. There are many turns possible, but only one direction, one path to the roots is possible. That is how the grounding/bonding has to be done.

Parts of the car that should be at zero potential and are not is a problem, but that doesn't mean that you automatically have a ground loop. It just means that there is too much resistance in that part's grounding/bonding.

"Bonding" is the term usually used for 'grounding' stuff when it is RF power being discussed or used. "Grounding" is the term used when talking about (mostly) DC though it pops up in AC too. (AC people are weird, they don't like to discuss that their 'neutral' and their 'ground' are connected together at the breaker box. It's like what ever happens in that box is magic or something.)
 
"ground loops" should not be an issue if the only ground your stereo system uses is the chassis of the radio/amp/etc to the vehicle ground. speaker wires "common" should not be grounded. I.E. every speaker has 2 wires going to it a +/- red/black DO NOT hook the "-" speaker wire into the vehicle ground anywhere at all.

as far as most any A body i've owned or seen, there is a ground strap from the back of the engine block to the firewall. and the neg batt cable goes to the engine.

if your stereo is still noisy you can put a filter on the power wire.

http://www.ebay.com/itm/Car-Stereo-...oise-Filter-Suppressor-Isolator-/160950412528

also called "noise supressors" they regulate excess noise from other devices on your auto's power grid.
 
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