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5th Gen Track Car

Posted: Sun May 16, 2021 5:30 pm
by sol-lude
ek9sid wrote:
Sun May 16, 2021 5:24 pm
What voltage are you getting whilst the car is running?
Drops constantly until the car dies
Ive got the battery at 12.58v just now but wont start without jumper pack

5th Gen Track Car

Posted: Sun May 16, 2021 6:51 pm
by ek9sid
Have you tried a different battery? I recently had a battery issue that was acting similar to how you're describing.

5th Gen Track Car

Posted: Mon May 17, 2021 9:42 am
by sol-lude
ek9sid wrote:
Sun May 16, 2021 6:51 pm
Have you tried a different battery? I recently had a battery issue that was acting similar to how you're describing.
Could well be mate I will check if I have a spare

A little more to the issue. Trickle charged overnight started 1st time this morning, whilst idling the volts read 11.57 and dropped much slower than yesterday. Turned car off and volts were 12.81.

5th Gen Track Car

Posted: Mon May 17, 2021 11:02 am
by Drax
check the connection from the loom to where it connects to the alternator, there's a green plug by the electrical connection on the side but it is one on the front that can easily snap off - Ive had this twice and your car wont keep voltage long before it dies.

5th Gen Track Car

Posted: Mon May 17, 2021 2:29 pm
by Vtecmec
Drax wrote:
Mon May 17, 2021 11:02 am
check the connection from the loom to where it connects to the alternator, there's a green plug by the electrical connection on the side but it is one on the front that can easily snap off - Ive had this twice and your car wont keep voltage long before it dies.
I've had that too, I only found it when fitting a new alternator to fix the problem. :lolno:

5th Gen Track Car

Posted: Tue May 18, 2021 10:08 am
by sol-lude
Sorry lads, what connection are we talking about? ive had a look and can only see the green one into the alternator.

had the Neg off the battery all day yesterday and used jumper cable on good earth and wouldn't start.

5th Gen Track Car

Posted: Tue May 18, 2021 10:44 am
by Scott560
sol-lude wrote:
Tue May 18, 2021 10:08 am
Sorry lads, what connection are we talking about? ive had a look and can only see the green one into the alternator.

had the Neg off the battery all day yesterday and used jumper cable on good earth and wouldn't start.
'well theres your problem'



First image on here, you can see the alternator - and the green connector for the multiplug. Just beneath that, on the front of the alt pointing towards the radiator is a threaded gold/brass stud, a nut , and then hopefully a big ring terminal with a fat wire coming out of it. This is the main charging feed to the battery. If its snapped off, that'll be why its not charging.

The multiplug alone is not enough for charging to commence (the wires are far to thin to carry 80+amps)

Be careful - the wire is permanently live, so make sure you disconnect the positive terminal from the battery unless you want to weld your tools together or blow the massive fuse which will probably be a pain to get hold of at short notice.

5th Gen Track Car

Posted: Tue May 18, 2021 11:20 am
by sol-lude
Right got ya, the gold/brass nut and wire are whole with no corrosion on it. cleaned up one of the earths and put additional earth on and she started first time but the running volts were around 11.58 but holding steady not dropping.

5th Gen Track Car

Posted: Tue May 18, 2021 12:30 pm
by Scott560
in any event, 11.58 is too low.

Check the voltage at the alternator terminal to rule out bad wiring, cracked fuse or nackered fusebox etc. If the big screw terminal at the alternator isnt at least 13v then its likely the alternator is at fault.

You can try a different battery, but i doubt it is the cause. If the battery was faulty and dragging the voltage down, the alternator wiring would be very hot or the battery would be very hot to the point of being obvious.

Does the voltage hold steady when the headlights are on? I suspect the alternator output is very weak and with some load on it, the battery voltage will most likely continue to drop.

5th Gen Track Car

Posted: Tue May 18, 2021 1:26 pm
by sol-lude
Alternator voltage same as battery so putting down to alternator, switching the lights on etc doesn't seem to change the voltage.

Ill try the 2nd hand one again and see how i get on.