JRo

Member
Hi all,

As the title suggests, Earth and electricity newbie here.

Question: does temperature affect earthing?

Context: Been having some issues recently. I’ve cleaned up some of the earth connections and relays (previous owner installed loads), most of the problems with lights etc are better but the starter still needs a jump first thing. After that she’ll start first time all day.

Any advice/ideas very welcome.

Thanks
 
Or maybe the starter is faulty.
The 2a had the same issue, starter would be very slow or nothing first try. Once it was going it would be fine for rest of the day, new one fixed it.
 
Thanks for jumping in everyone. I’ve tested the battery, seems in good shape. Sounds like it’s probably the starter - I’ll clean up the connections and go from there.
 
It’s worth cleaning up all the connections on/ near the starter motor you will be surprised the difference it makes, warm engines start easier , is the battery good
Will try that, thanks. Would a warmer engine be more forgiving to earthing issues?
 
voltage drop during cranking can be an indication of health
Tested how and for what? Voltage isn't necessarily an indication of a good battery.
The nice man at Halfords got his testing kit out and assured me it’s not the battery. This was a month or so ago and I’ve since installed an isolator switch thinking something was drawing pre ignition. Pretty sure it’s the starter or earth.
 
bad connections/bad earths can mean higher resistance in circuits, which mean less amps to do the required job.
a hot engine will need less power (amps) to the starter
a bad connection has higher resistance, which is why it will heat up, sapping more of the available power
 
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The nice man at Halfords got his testing kit out and assured me it’s not the battery. This was a month or so ago and I’ve since installed an isolator switch thinking something was drawing pre ignition. Pretty sure it’s the starter or earth.
in my experience, the average halford man is lucky to get kit connected to the right car, never mind tell you a battery is good or not.. their threshold is rather low
 
A further question - the earth from the battery, to the trans has a 2inch exposed section. Guessing that’s meant to be clamped to the chasis? It’s currently hanging free, collecting road juice.
 
in my experience, the average halford man is lucky to get kit connected to the right car, never mind tell you a battery is good or not.. their threshold is rather low
The average worker in halfords probably couldnt work out how to open the bonnet on a series - he'd spend half an hour looking for the bonnet release under the dash
 
bad connections/bad earths can mean higher resistance in circuits, which mean less amps to do the required job.
a hot engine will need less power (amps) to the starter
a bad connection has higher resistance, which is why it will heat up, sapping more of the available power
Makes a lot of sense. Thanks Kermit!
 
bad connections/bad earths can mean higher resistance in circuits, which mean less amps to do the required job.
a hot engine will need less power (amps) to the starter
a bad connection has higher resistance, which is why it will heat up, sapping more of the available power
A curious side effect of a loose connection heating up is that it can sometimes improve the conductivity by closing the gap. That's what may be going on here.
 
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A further question - the earth from the battery, to the trans has a 2inch exposed section. Guessing that’s meant to be clamped to the chasis? It’s currently hanging free, collecting road juice.
I don't think so, I can't remember how the chassis gets earthed, it's five years since I did my Lightweight and ten since I had these problems on an SIII, but I'm pretty certain that each earth strap only does one job.
 
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Ours had an earth strap going to the chassis near the starter motor, might have been on the starter mount bolt.
Why is you battery in the back, what Series have you got?
 
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