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  #1  
Old 29-04-2017, 04:26 PM
mrzed mrzed is offline
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Hot positive battery lead on 74 260 z

Is there any common reason the positive battery lead gets hot whilst cranking to start?
It gets that hot it's almost melting the plastic coating coating .
I have been having starting issues and when pounding the battery for a few minutes the cable and the terminal on the positive too hot to touch
Would replacing the battery cables solve this or could something else be causing this?
They are old original ones.
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Old 29-04-2017, 04:35 PM
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yellowz yellowz is offline
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I just know someone is going to say this better. I'd get a stronger cable that is big enough to take the current running through it safely.
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Old 29-04-2017, 05:04 PM
mrzed mrzed is offline
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Yeah I think the best bet is start with fresh cables ,
This could be the reason when it was running before the starting problems I'm having ,
It would be running fine then it would start to miss like as if I was switching the ignition on and off quickly then some backfiring and then eventually cut out .
I thought it was fuel related but fuel is getting through
Could be a dodgy coil too I'm thinking because there is not a really good spark at the plugs
I'm running the old points system at the moment but I have a 12-80 280zx dizzy I'm wanting to fit but need a 280zx base clamp and timing plate .
I have a new 280zx coil and rotor arm also
Maybe best to try and get the new leads and try to get a dizzy clamp then start from there
Instead of wasting time with old tech.
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Old 29-04-2017, 05:43 PM
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I'd say its a poor earth.
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Old 29-04-2017, 05:56 PM
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Are you talking about the +ve to the starter? I think it is too thin for sustained cranking.
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Old 29-04-2017, 06:00 PM
mrzed mrzed is offline
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I'm talking about the black positive cable that goes on the battery jon
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Old 29-04-2017, 06:25 PM
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Quote:
Originally Posted by mrzed View Post
I'm talking about the black positive cable that goes on the battery jon


I'd agree with Franky then
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Old 30-04-2017, 12:42 AM
mrzed mrzed is offline
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Any suggestions on where to start looking for a bad earth?
Is that like the terminals on the starter motor ?
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Old 30-04-2017, 09:20 AM
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The battery terminals, the starter terminals and the big earth strap on the top bolt connecting the block and bellhousing.
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Old 30-04-2017, 02:00 PM
mrzed mrzed is offline
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The big earth strap could be be the culprit, I will investigate,cheers Jon
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Old 30-04-2017, 10:53 PM
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Quote:
Originally Posted by franky View Post
I'd say its a poor earth.
What I was thinking.
You could always add another fresh earth from the block to the chassis somewhere, as that isn't going to hurt either
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Old 01-05-2017, 01:28 PM
mrzed mrzed is offline
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Sorry franky, I never thanked you too .
Right been in the garage to check connections on the starter , cleaned them up, took the - terminal off cleaned that too .
Where the - terminal is bolted to the starter motor bolt ,should there be a braided wire strap going to the bodywork or chassis too ?
There isn't one
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Old 01-05-2017, 10:56 PM
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No earth strap from starter should be from the battery to the bulkhead, i suspect your starter motor may be drawing too much current unless your cranking it over for minutes at a time
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  #14  
Old 02-05-2017, 03:45 PM
mrzed mrzed is offline
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Smile

Put a new earring strap on today from battery to bulkhead and a new condenser and seems to have solved my starting and running issues ,also the positive terminal is cool,
I would like to thank you all again for your help.
Now got to put it in for an mot and hopefully I will be enjoying my car again sometime soon
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