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trying to trace parasitic current draw

A993LAD

Well-known member
Joined
20 Mar 2007
Messages
721
I'm still trying to track down a parasitic current draw which is causing starter problems if the car sits for more than a few days.

It looks like the current draw when the car is parked is around 60 mA. Would that be enough to drain the battery below a level that will turn the starter motor after 2 - 3 days.

I read somewhere that the current draw for a 993 should be less than 20mA but I also just watched a Youtube video where somebody was saying most modern cars regularly draw 60 - 100 mA.

The battery reads about 12.7 V after a run but is down to 12.1 after a few days. The battery is expensive and pretty new - about 1 year old.

I've tried pulling each of the 40 fuses in the main fuse box whilst the meter is connected but the current draw remains at 60mA. Are there other fuses or circuits I need to check if none of these fuses seem to affect the current draw?
 
I'll start what will be a long list of possibilities with two that happened to my C4...

Alarm siren battery was worn out and no longer retained charge, meaning that it constantly needed to be topped up. (It's now on eBay)

My Climate Control Unit failed in some convoluted way, meaning that it would sporadically fire various parts of the system even when the ignition was off.

Good luck - it's a right Julian Clary trying to locate these sort of faults.
 
two very likely options:

Old tracker, often the old ones were mounted close to where the first aid kit was screwed onto the metal panel work then covered in foil tape. often wired into the relays in the front compartment next to the spare wheel.

modern units are much smaller and easier to install better hidden.

or has been suggested your alarm siren battery is dead, try disconnection the siren and see if that helps.

Neither of the above cause would be found by pulling fuses, the CCU draw should be found by pulling the right fuse.

Have a look on Tore b's sight, he has good fault finding info on it for the CCU.


Good luck
 
Thanks guys

I'm pretty confident there is no tracker on my car .

The ccu was sent off to Torre and refurbished and sent back with a clean bill of health so hopefully that should be okay

There is an alarm siren in the engine compartment and I had no idea he had its own battery so I'll try disconnecting that
 
Alarm Siren

Is this the alarm siren mentioned? located in rear near side wing area (approx 100mm square box) It was not connected in my car but the wiring is still present, two push-in connectors. I have since removed the unit, no idea if it actually works!
 

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Battery draw

A993LAD said:
Thanks guys

I'm pretty confident there is no tracker on my car .

The ccu was sent off to Torre and refurbished and sent back with a clean bill of health so hopefully that should be okay

There is an alarm siren in the engine compartment and I had no idea he had its own battery so I'll try disconnecting that

Consider a battery immobiser, bit of a pain having to reset the clock but if it saves the starting hassle job done.
 
Does your car have an obc? A duff resistor in my lcd display left it permanently lit and was the cause of my problem.
 
Thanks for the additional tips

My car doesn't have an OBC

And I've just ripped the siren out of the Engine bay and disconnected the wires that went to it

The car is still drawing 60 mA from the battery though

What next guys ?

And does anybody have a view on whether 60 mA is too much .
 
Same prob. was traced to a faulty door swtich contact.
 
60 milliamps = 0.06 of an amp .. thats not a drain .. thats pretty much normal for a car with a clock , radio and an alarm system .

You could try unplugging the radio if you want .

I would check the charge rate , the battery condition and is the car used on short journeys as the drain seems far to low to me to flatten a battery in 2 days .

You may well have a starter motor issue or lead which is over drawing current and so giving the syptoms of a flat battery .. but you dont have a drain .
 
How old is your battery? ........ might be worth changing it ........ my car at one point was "eating" batteries ....... but after I had a defunct tracker ripped out ....... also it had two alarm systems fitted ........ one factory and the other after market ..... all ripped out and started again which made life one helluva lot more easy.

Good luck ....... I daresay it will be a "duh" moment when you find the problem ...... :)
 
Odd time of the year for the battery to struggle but I would start there.

Second we all use our cars regularly but we sometimes forget how infrequent those regular drives are and I would agree with Allen E and fit a battery isolator.

I use the £3 ones on eBay and all other outlets that take 3 mins to fit on the neg baterry terminal and can then isolate or connect the battery by a quarter turn. They are great 👍
 

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