• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Ground strap on head to firewall

x91evo

NAXJA Forum User
Location
naxja sucks dick
Do you need this ground strap?
Would this prevent the ignition from working properly?
I am asking because there is also grounding wires on the side of the block that go to the battery and chassis.

E43AD83B-E866-4CF9-9082-19E1A7D80B34-6558-0000042FF09E40D1_zpse8ed91f2.jpg


thanks Kingkong0192 for the pic Kingkong0192
user_online.gif

NAXJA Forum User
 
Yeah, that one's important, especially during cranking, when a ton of current is being drawn by the starter, grounded through the block, that strap, and a few other wires. If you have crummy grounds it can throw off various sensor readings due to the voltage difference between the chassis and the block.

I have had jeeps run decently without it, but grounding is marginal in XJs even without removing some. For reliability I would put it back on, or preferably replace it with heavy gauge welding cable. It's routed to the rear most head stud on the driver side from the factory but if you want to put it back on another one that's more accessible there is no reason not to, just clean the rust off first.
 
Yes, that was apparently undersized at the time of production. Ground wires a a HUGE source of intermittent gremlins.

Search users: 5-90 and Cruiser for tons of info and guides on refreshing and upgrading electrical issues.
 
The question is more "what does a bad ground NOT cause to go haywire?"


Replace it with a standard battery cable of appropriate size. You COULD get a replacement braided strap at the parts store, should be right next to the battery cables.

That thing is toast.
 
I replaced mine with a custom 2 gauge one from the local battery shop with copper ends.
 
It originally went to the rearmost head bolt/stud on the driver's side. Remove it from the firewall and scrape the firewall to bare metal along with cleaning up the eyelet. Re-fasten securely.

At teh other end, clean it up and attach it under a fuel rail bolt on the intake manifold.
 
Well so I guess its a good idea to replace it reguardless,
But I cant help but think the flimsy sheetmetal firewall isnt really a good ground to begin with.

So I think I will route it from the head to the battery directly
 
Route it to the firewall. It's a pretty damn wide piece of flimsy sheetmetal. If you want to route it elsewhere, go to a frame rail.

There's already a ground to the battery IIRC - and one from the battery to the fender. It really does need them all to keep sensor readings and gauge indications accurate, especially while cranking, and losing any one of them will put you in danger of going absolutely nowhere if you happen to lose another, with screwy odd issues happening in between.
 
Route it to the firewall. It's a pretty damn wide piece of flimsy sheetmetal. If you want to route it elsewhere, go to a frame rail.

There's already a ground to the battery IIRC - and one from the battery to the fender. It really does need them all to keep sensor readings and gauge indications accurate, especially while cranking, and losing any one of them will put you in danger of going absolutely nowhere if you happen to lose another, with screwy odd issues happening in between.

Yea its probably a good idea not sure what else it would affect.

As long as you understand all the metal in the car is basiclly the - Terminal lol
 
Re: Re: Ground strap on head to firewall

Well so I guess its a good idea to replace it reguardless,
But I cant help but think the flimsy sheetmetal firewall isnt really a good ground to begin with.

So I think I will route it from the head to the battery directly

Your whole jeep is flimsy sheet metal! Lol. Good grounding is very important, especially on efi engines.
 
Your whole jeep is flimsy sheet metal! Lol. Good grounding is very important, especially on efi engines.

Valid point! haha

Yes I think thats where I made the mistake. Been having a "no spark" issue for the past couple of days.
Makes sense that the head would need a ground itself.
Hope I just fried my ign coils
 
Don't run it straight to the battery. Run it to the firewall, just make sure your connection at the firewall is good and clean (scrape rust/paint off where the ground wire makes contact). The block itself is grounded to the body and then the body to the battery via a stud in the passenger side inner fender. The reason for the ground strap at the head is that the head needs a little extra grounding due to it's contact surface with the block being isolated by the head gasket.
 
Not sure I agree with that, since there are around a dozen highly tensioned head bolts with metal to metal contact from the bolt to both sides of that junction, but I do agree the block needs to be grounded to the chassis.
 
If you lose a ground, things stop working ... that generally won't fry anything.

Well I was thinking possibly fried the ignition coils since power couldnt ground well enough.

x91evo,

What year is this XJ?
2000 with 172,000 Miles

You need a ground to the chassis/firewall.
Yea I ended up replacing the ground strap with a pre made ground

Don't run it straight to the battery. Run it to the firewall, just make sure your connection at the firewall is good and clean (scrape rust/paint off where the ground wire makes contact). The block itself is grounded to the body and then the body to the battery via a stud in the passenger side inner fender. The reason for the ground strap at the head is that the head needs a little extra grounding due to it's contact surface with the block being isolated by the head gasket.
Yes I understand how to get a good ground lol
I grounded the block to the chassis by the motor mount on the passanger side of the car, then to the battery. All 0AWG wire. Quality connectors. Electric is my stuff

Not sure I agree with that, since there are around a dozen highly tensioned head bolts with metal to metal contact from the bolt to both sides of that junction, but I do agree the block needs to be grounded to the chassis.
Yes I didnt realize at first it was the head stud itself that it was grounded to
 
Back
Top