Help please only 8 Volts and Ignition Vk Commodore

[Fingers]

Im Stumped, hopefully someone with far more knowledge can help

I have a VK running a 308 and all was well until last week i tried to start it but only getting clicking sound from the starter

I checked everything and left it. Came back next day and it started. turned it off straight away
and tried again but only clicks again.

When I turn ignition on i see its only reads around 7-8 volts

I charge the battery checked all the connections, check earth to engine all seem good
I swapped battery's but no difference

Still only reads 7-8 volts.
not enough juice to crank stater only make it click as it hits the flex plate teeth

 

[Trevor loves holden.]

Is that reading off the battery or down at the starter motor? What is the battery reading off the car? Maybe your Alternator is causing the issue or old cables off the battery ant passing the full current.. His the workshop book save it if you like, http://www.allcarmanuals.com/factory-service-manual-73-Holden-Commodore-Calais-VK.html

 

[Immortality]

It's common for the ignition switches to burn out in the early girl Commodores as the starter motor solenoid is powered directly via the ignition switch. I suggest upgrading the wiring and putting in a relay so the starter solenoid is powered directly from the battery via a relay which will ensure a good 12v supply to the starter solenoid and save the ignition switch just like all the later model Commodores (and all other modern makes and models) are wired.

I would also do the same for the headlights, it makes em brighter and stops the headlight switch burning out just like the ignition switch.

 

[Fingers]

Using a voltmeter the alternator is charging at 13.8 volts at the battery

If I test the the wire that goes to the starter where it comes out of the wiring loom (not the main battery feed) it only shows 7volts
so seems the voltage from ignition is the problem
I can "jump' start the starter solenoid straight from the battery no problems

I have looked under the dash and there is an exiting relay attached to the ignition wires.
Black to 85
Pink to 30
Brown to 86
Red to 87

Doesnt make any difference if the relay is connected or not

When the car is at idle the dash voltage gauge show 7-8 volts
when at 2000rpm is at 12 volts
if i turn on my headlights the voltage gauge drops to zero

Unfortunately previous owners have made a bit of a mess so it hard to find out what is going on

I appreciate all your help and suggestions

 

[Immortality]

Sounds like a wiring problem for sure. It is best to have the relay in the engine bay and wire the main feed directly from the battery so it takes the load of the main feed wire going into the car. My old VK had a burnt loom due to a short so I ended up having to replace parts of the main +12 feeds going to the fuse box.

Unfortunately you're going to have to clean up and fix what ever the previous person did.

 

[Skylarking]

Just remember that the wires on a VK are probably starting to get somewhat brittle which can cause all sorts of problems. The worst problem can be a short causing a fire which can consume your car.

Since the wiring seems like a bit of a mess from what you say, it may be worth looking into a new loom with upgrades for starter and headlights as immortality suggested.