Lotus Elan and Lotus Elan Plus 2 Forums

What's the best place to connect the Main Battery Earth to, in the rear / boot area?

There seems to be at least two options - the LHS Turret Mounting Screw or the rear chassis bolt in the well of the boot, seem the most likely candidates?

Does anyone prefer the one over the other, and does either point foul any of the trim finishes, etc?

Your thoughts would be appreciated - or have I found another question that can't be answered? (like the last one regards Handbrake cable inner!)

Thanks,

Phil.

Sometimes my Lotus makes me cry.

My S4 is earthed on the rear chassis bolt. These days, when the car leads a pampered life, the connection stays clean and dry but back when it was my daily driver and left out in all weathers it was frequently a ball of corroding mud so I could understand why you'd move it to the turret screw

Mine is the rear chassis bolt but originally was problematic until I figured out what was going on.
The chassis bolt comes up from underneath and tightens on the bobbin. The extra thread that protrudes up into the boot is what you tighten the earth cable onto.
The problem with this is that if the bolt is slightly loose, and not making a good contact with the chassis, you can tighten the earth strap down onto the bobbin as much as you like and still not have a good connection.

My answer was to run a drill through the bobbin taking the threads out so the whole lot, ( cable, bobbin, and chassis), all clamp up solid.

Cheers
Ralph.

My Sprint is earthed on the rear chassis bolt as well and this works well as long as the connection is clean and tight. As the bolt comes out in a little 'groove' it does seem to get quite dirty (water seems to collect here if any get's into the boot) and I have had to clean the connection on occasions to get a good contact. It's the first place I check if I have starting issues. Like 69S4 my car lives a more 'pampered' life so it's less of a problem than it used to be. At least it's nice and easy to see. An occasional spray with WD40 helps.

Carl.

Phil,
It seems that a bad earth manifests itself in a variety of ways, especially anything involving a high current draw. On my Elan, the normal earthing point for the battery is the L/H rearmost body mounting bolt at the bottom of the boot. To try and avoid earthing problems, I have made a few modifications.
Firstly, I use serrated, lock washers that bite into the metal, both under the bolt head and nut. This ensures a good contact betwen the bolt and chassis and double locks the nut (self locking nut).
Secondly, I had a short cable, same gauge as battery earth cable, made up to jump from the L/H bolt to the R/H bolt to double the earthing path. I used the serrated washers between all contact points.
Thirdly, I had another cable made up (same gauge again) to connect the L/H radiator mount bracket (where most of the earthing under the bonnet is done) to the chassis. Again using the serrated lock washers.
I did all this to ensure an uninterupted earthing path from the battery, to the chassis and then on to all the earthing points on the chassis, of which there is several.
Regards,
Colin. '68 S4.

l10tus wrote:What's the best place to connect the Main Battery Earth to, in the rear / boot area?

There seems to be at least two options - the LHS Turret Mounting Screw or the rear chassis bolt in the well of the boot, seem the most likely candidates?

Does anyone prefer the one over the other, and does either point foul any of the trim finishes, etc?

Your thoughts would be appreciated - or have I found another question that can't be answered? (like the last one regards Handbrake cable inner!)

Thanks,

Phil.

Sometimes my Lotus makes me cry.

Down in the boot.

Whenever you are making such connections cover ALL surfaces of spade and stud in a goodly dollop of Vaseline.
When you tighten up the it migrates away from the mating surfaces but fills in all the gaps so preventing corrosion inside and out.

Especially good for car batteries just don't be shy with the Vaseline.

Simon

l10tus wrote:Sometimes my Lotus makes me cry.

My cousin has a theory that technology only behaves with people that are unafraid to break it.
You don't even need to really know what your doing just keep the kit scared.
So man up Phil, make sure it knows that it is you that holds the hammer!

Hi

The battery earth in the bottom of the boot has always caused problems - which can be solved. I recall a virtually new Plus 2 not starting due to poor battery earth. I'm planning to earth my S4 to the chassis upright when I get round to that stage.

Regards Gray

Gents,

Thanks for the replies, most helpfull.

Did anyone have problems with the cable fouling any trim in the Turret location, as I'm about to re- trim the car out and at present there's no carpets, etc fitted - so I wouldn't know if anything gets in the cable's way ?

Many thanks,

Phil.

'72 DHC Sprint.

Sometimes my Lotus makes me cry.

Hi Phil

I long ago gave up on the original boot earth and rigged up one to the top of the tower- that was 20 odd years ago and never a problem since. I also got rid of the engine to chassis earth (the one at the engine mount) and rigged one from one of the tapped holes in the block under/near number one plug. The hole is in a small flat section above the ex manifold. I ran this to the front chassis/body mounting bolt.

John

I would agree with John _ always found the original earth in the boot unreliable.

Had no problems routing a good chunky earth cable to the rear turret - in fact for good measure I ran an earth from the other turret ac well!

I also ran earths from both front uprights to a couple of junction boxes in the engine bay and then earthed anything that needed earthing via the junction boxes. No more slowing of the indicators when it rains.

Richard

An old thread, I know, but a bit of advice, please.

I removed the chassis tower bolt so that I could do the earth thing. New cable sorted out, but now the bolt is proving difficult to replace as the body/chassis alignment has moved by a couple of mm.

Should I just jack up the body until it all aligns again?

Thanks in advance!

Zlinster wrote:An old thread, I know, but a bit of advice, please.

I removed the chassis tower bolt so that I could do the earth thing. New cable sorted out, but now the bolt is proving difficult to replace as the body/chassis alignment has moved by a couple of mm.

Should I just jack up the body until it all aligns again?

Thanks in advance!

I would imagine that perhaps the chassis felt has compressed so much over time that when you sat inside the car your weight allowed the body to sink a little - I assume you removed just the one bolt?
I had my body on and off its new chassis a few times and each time I would have to insert a pointed pry-bar through a bobbin and into the chassis and give it a little wiggle to get it to line up for the bolt again.

Regarding the earth, my S4 has a Spyder chassis with the integral seat belt mounts. These are threaded all the way through so I have run my earth cable to the back of that mount.

Mike

Thanks Mike. I'll try that.

Zlinster wrote:Thanks Mike. I'll try that.

I see you also have an S4 so you should have the brace that goes between the two turrets. You might want to just loosen the bolt in the opposite turret just enough for the brace to become loose. The holes in the brace are elongated slots so loosening the other side might make it easier to get the bolt through the brace, and then through the bobbin into the thread.

Mike