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Cossie0_4

Hi got a r32gtr and having voltage issues
I've tested alternator direct 14.5v
tested battery 12.6
battery has been relocated into boot but I do a voltage check engine running 13.2 at batttery
if I connect meter at connector in engine bay for battery live and earth to body 13.2 if earth to engine 14.5
if I connect a earth lead from body to engine car won't start but if I attach jump lead from another car with engine running my car will start perfectly any help apreciated as ran out of ideas thanks
 
Did it work OK before you moved the battery to the boot?

Have you extended the battery earth to the boot or is the battery earthed directly in the boot?

Did the battery earth connect directly to the engine?

What size cable have you used to extend the battery leads?

There must have already been an engine to body earth strap, so fitting another should make no difference let alone prevent it from starting.
 
Yes it was fine before as battery been in boot a while I think it's since we put engine back in it did used to start but cranked slowly
battery didn't earth to engine but it does now as we changed it
battery is earth from battery to boot hinge and doesn't come completely from engine to battery
earth I put in is 16m 170amps
hope this helps
 
Yes it was fine before as battery been in boot a while I think it's since we put engine back in it did used to start but cranked slowly
battery didn't earth to engine but it does now as we changed it
battery is earth from battery to boot hinge and doesn't come completely from engine to battery

earth I put in is 16m 170amps
hope this helps
You may well find this is the problem, you need good continuity,are you relying on boot hinge body work to bat terminal ; if so is it secure and corrosion free . boot flor too?
 
I have put new earth cable on now earth from body to engine and alternator body to strut top and it def cranks faster but still a volt drop cheers
 
I have since added a earth to engine and a earth to alternator bracket both of which earth to the strut top and still the same cheers
 
Yeah , especially the horse power of that car . I missed the 16 mm
 
No earth doesn't go from boot to engine and what size cable should I get to replace
also what is a excepted volt drop from alternator to battery with it being in the boot thanks
 
You said earlier that you have earthed battery direct to engine , but then through boot hinge body work . You do not say what size cable you have used from battery to starting circuit; that car could draw 250 + amps during starting, and could have already damaged the cables you have used . this could be why the starting is deteriorating.
If the chassis is in good condition and no corrosion ,there is no reason why you could not bolt the earth to the boot floor direct to the earth on the battery. Make sure the floor is back to bright steel though , then protect it from corrosion. Make sure that the earth is definitely sound to the engine or wires will burn trying to carry starter current ,or any other high load.
 
No earth doesn't go from boot to engine and what size cable should I get to replace
also what is a excepted volt drop from alternator to battery with it being in the boot thanks

Volt drop is dependant on length and current, and the acceptable voltage tolerance.

What is the minimum voltage that should be delivered from the battery to the engine for it to start properly? This will depend on your particular starter motor.

Just as a reference point a Landrover has the battery under the passenger seat and has a 50mm cable to the starter motor for the approx 4' run.
To go the full length of a car I wouldn't be at all surprised if you needed 95mm or larger
 
Add to that if you have moved the battery to allow you to put an even bigger engine in?
You need to think of the cold cranking and duration of high current draw.
 

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