Slow cranking and low voltage

[Rabster The Outlaw]

Help Question to the R32 GTR Gurus 

Lights flickering and voltage jumping around. Had the alternator reconditioned about 6 years ago. I noticed last year before putting the car away that the voltage on the USB charging adapter was fluctuating 14.2- 14.6 roughly when the car was idling in the garage. 

Since then I have moved the battery to the boot, fitted 
0gauge to the front of the car for 12v 
4guage from battery to chassis in the boot 
Grounding kit in the engine bay cleaned up the points in the bay with a wire brush and in the boot where it’s connected. 

Changed the dash lights to LED due to a number failing so now it’s more readable at night 

However still got the voltage fluctuating and lights flickering

Anyone got any further tips to try before replacing the alternator and possibly fitting a PDM to replace all fuses and relays (wire tuck at the same time)
 

took car out today and watched the voltage meter that was fitted with the USB out on it and on cranking it drops to 8.x Volts before starting so could be battery related but the battery was checked 2years ago and has lived on a Ctek battery charger / conditioner whilst stored

 

can anyone offer any pearls of wisdom 

[joshuaho96]

Start by load testing the battery. If the internal resistance is too high and the energy capacity too low it won't provide the amps needed to crank. From there start measuring voltage at the battery terminals vs at the engine bay where the power goes in. If the voltage drop is substantial especially when cranking you relocated it wrong somehow.

[niZmO_Man]

Do you notice any other noises in the car? I was going to suggest unplugging the small plug from your HICAS controller under the rear parcel shelf (if you still have it, that thing does weird shit to my car).

[Rabster The Outlaw]

Ok so just been out to check everything and have cleaned up the boot connection to the chassis and the starting seems a little less “laboured” but still pulls the voltage down to about 9v 

 

however when it’s connected and running now after cleaning everything up it’s sitting at 15.5v on the in built Chinese usb charger with voltage display. The in car one is also jumping around 

 

my voltmeter is with my work tools buried in the back of the pickup so will dig that out tomorrow and check it at the battery when cranking and running for more accurate readings but I think the alternator might be in its way out but that doesn’t answer the slow ish starting but if it’s been overcharging at 15v+ it has possibly fried part of the battery 

[Rabster The Outlaw]

5 hours ago, niZmO_Man said:

Do you notice any other noises in the car? I was going to suggest unplugging the small plug from your HICAS controller under the rear parcel shelf (if you still have it, that thing does weird shit to my car).

No other noises apart from the usual knocking noises where I need to refurb shocks and bushes lol

[Rabster The Outlaw]

The only thing I did notice was that my Hicas light on the dadhboard is on all the time now since swapping to LED warning lights as well 

 

probably not connected and need to get the hicas serviced or locked out 

[GTSBoy]

9 hours ago, Rabster The Outlaw said:

probably not connected and need to get the hicas serviced or locked out

Good luck finding anybody, especially in the US, who can "service" HICAS. Just do as Niz advised and pull the smaller of the 2 plugs form the HICAS CU. Will disable HICAS without any other negative effects, and will kill the light on the dash at the same time.

[TurboTapin]

On 4/5/2024 at 12:17 PM, Rabster The Outlaw said:

Ok so just been out to check everything and have cleaned up the boot connection to the chassis and the starting seems a little less “laboured” but still pulls the voltage down to about 9v 

 

however when it’s connected and running now after cleaning everything up it’s sitting at 15.5v on the in built Chinese usb charger with voltage display. The in car one is also jumping around 

 

my voltmeter is with my work tools buried in the back of the pickup so will dig that out tomorrow and check it at the battery when cranking and running for more accurate readings but I think the alternator might be in its way out but that doesn’t answer the slow ish starting but if it’s been overcharging at 15v+ it has possibly fried part of the battery 

Confirm voltage on your battery directly with a multimeter. If you are in fact at 15.5VDC+ then your voltage regulator on your alternator is shot, which also explain the voltage flicker. Charging your battery at those voltages will also lead to eventual damage. 

Edited April 9 by TurboTapin