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Hippy

Help needed - electrical problem when refitting battery

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On 21/10/2019 at 20:54, ttrw2 said:

Good news that you've located 0.7A of the 1.2A drain and that it's not the new FSU or the aux fan.

 

I'd resist simply throwing more parts at this stage and try to determine why the heater valves are sinking that much current when they're off (strip and inspect electrical side of them). If you have no appetite for this then replace as Dan suggests, but you may find it is the HVAC panel (the controller) sending the current there rather than the heater valves demanding it and you need to repair/replace HVAC panel next. i.e. it becomes a process of elimination via part substitution instead of getting to the root cause.

 

Still ~0.4A drain from somewhere yet to be determined - this is enough to drain a fully charged battery below a cold start threshold in 10days or so. Did you try the rear screen demister?

 

Yes, hopefully slowly getting there!

 

Unfortunately I'd already ordered a replacement part before I read your message - hopefully be with me for the weekend.

 

Yes, I did check the rear demister, ( fuse 20 if I'm correct ), which read 1.18A  as per the majority of the others. Only fuses 4 and 9 affected the reading.

 

Does anyone know if the HVAC unit can be checked / repaired, or is it a throw away item?

 

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There's a fuse in the boot for the rear demister too (at least, on the saloon there is). Fuse 66.  May be worth checking the other fuses in there too (CD changer, nav, radio, etc) in the search for the remaining ~0.4A drain.

 

 

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On 23/10/2019 at 12:32, ttrw2 said:

There's a fuse in the boot for the rear demister too (at least, on the saloon there is). Fuse 66.  May be worth checking the other fuses in there too (CD changer, nav, radio, etc) in the search for the remaining ~0.4A drain.

 

 

 

Good idea - I'd forgotten those - they are out of sight behind a flap on the Touring. Just had a quick peek and I can't see any clear indication of which fuse governs what - I'll have a proper look at the weekend when I fit the heater valves.

 

Ref the valves - is there much water loss when changing them? I've read somewhere to swap one hose at a time. Does that mean that the valves are closed until power up ? @d_a_n1979 what was your experience when you did yours?

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Why would the heater valves be the actual cause of a drain? If current is flowing through those while it is asleep then it is because the module that drives them is making that happen. I believe they are just solenoid valves without active electronics. The wiring diagram shows the live supply is switched by the module so they can only draw current if the module applies a voltage.1952073563_heatervalves.JPG.ea82f74a648fd15404cf7c80cb6e2785.JPG

 

Can you confirm you are doing all these checks once it is fully asleep? If it hasn't gone to sleep then there may well be a small residual current in many circuits that is normally there. You are looking to reduce the 0.74A it is drawing in sleep mode to around 0.04A, not reduce the 1.18A it is drawing while 'idle but not yet asleep' or have I missed something in your description?

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1 hour ago, Hippy said:

 

Good idea - I'd forgotten those - they are out of sight behind a flap on the Touring. Just had a quick peek and I can't see any clear indication of which fuse governs what - I'll have a proper look at the weekend when I fit the heater valves.

 

Ref the valves - is there much water loss when changing them? I've read somewhere to swap one hose at a time. Does that mean that the valves are closed until power up ? @d_a_n1979 what was your experience when you did yours?

 

Took me 10 mins pal and hardly any water loss. I just ran the car after and topped it up with maybe 200ml if that!

 

Easier to do it when the engines cold FYI

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32 minutes ago, THe39M5 said:

Why would the heater valves be the actual cause of a drain? If current is flowing through those while it is asleep then it is because the module that drives them is making that happen. I believe they are just solenoid valves without active electronics. The wiring diagram shows the live supply is switched by the module so they can only draw current if the module applies a voltage.1952073563_heatervalves.JPG.ea82f74a648fd15404cf7c80cb6e2785.JPG

 

Can you confirm you are doing all these checks once it is fully asleep? If it hasn't gone to sleep then there may well be a small residual current in many circuits that is normally there. You are looking to reduce the 0.74A it is drawing in sleep mode to around 0.04A, not reduce the 1.18A it is drawing while 'idle but not yet asleep' or have I missed something in your description?

 

No idea; I discussed this with Clavurion; but the heater valve is what cause the battery drain in my touring. Swapped it out for a new one, no drain, at all!

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38 minutes ago, d_a_n1979 said:

No idea; I discussed this with Clavurion; but the heater valve is what cause the battery drain in my touring. Swapped it out for a new one, no drain, at all!

 

This still puzzles me with the same logic that THe39M5 just told.

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49 minutes ago, Clavurion said:

 

This still puzzles me with the same logic that THe39M5 just told.

 

Could it have just been the HVAC panel then? I replaced both, but the unplugging of the heater valve stopped my battery drain dead in its tracks!

 

I replaced that and the HVAC panel as a 'just in case'

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49 minutes ago, d_a_n1979 said:

 

Could it have just been the HVAC panel then? I replaced both, but the unplugging of the heater valve stopped my battery drain dead in its tracks!

 

I replaced that and the HVAC panel as a 'just in case'

 

If there's no voltage there's no current and the water valves should not have voltage from IHKA after vehicle goes to sleep mode.


 

Quote

 

The control module contains a fault memory in a non volatile RAM and incorporates a sleep
mode when the ignition is switched off. The control module will switch to the sleep mode
16 minutes after the ignition is switched off.

 

SERVICE STATION FEATURE
This feature prevents hot coolant from entering the heater cores after the engine is switched
OFF. It is designed to prevent a blast of hot air, on a restart, that would arise from coolant
bleeding into the heater cores (heat surge) when the engine is switched OFF.
If the coolant temperature is above 15 C, the water valves are powered closed for 3
minutes when the vehicle is switched OFF.

 

 

Edited by Clavurion

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Unplugging the valves would indeed stop the current draw but that doesn’t mean they are definitely faulty. They could be but the HVAC has to provide the current in the first place so if that isn’t switching off or getting powered down then it’s possible it’s the HVAC but also the control module. Now you’ve already proven that the car sleep mode works so that only leaves the HVAC. And I’ve not heard of anyone able to repair them so need to find a working replacement. 

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To clarify, I only let the car go into sleep mode once. As I only had limited time and a whole heap of fuses to work through, I didn't have the time to allow the car to go to sleep each time I pulled a fuse - 25 ish fuses x 16 mins each!!

 

As stated I'm not great with electrics, so my thought process was to use the 1.18A reading as a bench mark figure to see how pulling fuses altered this . The only time this figure dropped were when fuses 4 and 9 were removed. 

 

The heater valves will hopefully be with me for the weekend, so I might as well replace these anyway. Maybe I'll get lucky!!

However, how can I prove one way or t'other that the the HVAC  unit is functioning correctly? And if the problem does turn out to be the HVAC unit, I'm not sure how to proceed. How can  a used item be guaranteed fit for purpose? I should imagine a new item is big bucks:sad:

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37 minutes ago, Hippy said:

To clarify, I only let the car go into sleep mode once. As I only had limited time and a whole heap of fuses to work through, I didn't have the time to allow the car to go to sleep each time I pulled a fuse - 25 ish fuses x 16 mins each!!

 

As stated I'm not great with electrics, so my thought process was to use the 1.18A reading as a bench mark figure to see how pulling fuses altered this . The only time this figure dropped were when fuses 4 and 9 were removed. 

 

The heater valves will hopefully be with me for the weekend, so I might as well replace these anyway. Maybe I'll get lucky!!

However, how can I prove one way or t'other that the the HVAC  unit is functioning correctly? And if the problem does turn out to be the HVAC unit, I'm not sure how to proceed. How can  a used item be guaranteed fit for purpose? I should imagine a new item is big bucks:sad:


Source one from @Tims on here, it’ll come out of a fully working car I’d say

 

Or if you’re on Facebook, see if you can get one from one of the trusted breakers; Simon Garland

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So, nice dry day and went to fit the heater valves only to find........

 

20191027_132639.thumb.jpg.acf235c3a9031dacffbd4b6496ed55e7.jpg

 

....broken during transit:angry::angry:

 

Are we now thinking it would be worth replacing the HVAC unit as well?

On 24/10/2019 at 22:46, d_a_n1979 said:


Source one from @Tims on here, it’ll come out of a fully working car I’d say

 

Or if you’re on Facebook, see if you can get one from one of the trusted breakers; Simon Garland

 

Is this where you sourced yours from  Dan, or did you dig deep and go for a new item?

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10 minutes ago, Hippy said:

So, nice dry day and went to fit the heater valves only to find........

 

20191027_132639.thumb.jpg.acf235c3a9031dacffbd4b6496ed55e7.jpg

 

....broken during transit:angry::angry:

 

Are we now thinking it would be worth replacing the HVAC unit as well?

 

Is this where you sourced yours from  Dan, or did you dig deep and go for a new item?

 

Oh balls :( It is only that bit though, a cable tie will easily secure it in place as will the heater pipes, personally I'd use it, but ask for some £££ back from the seller due to it being damaged

 

I got my HVAC panel from Alex off these forums, but see if @Timshas one, if not, see if Simon Garland on the E39 groups on Facebook has one for you, he's breaking a few E39s currently FYI, just needs to make sure that the numbers match :) 

Edited by d_a_n1979

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55 minutes ago, d_a_n1979 said:

 

Oh balls :( It is only that bit though, a cable tie will easily secure it in place as will the heater pipes, personally I'd use it, but ask for some £££ back from the seller due to it being damaged

 

I got my HVAC panel from Alex off these forums, but see if @Timshas one, if not, see if Simon Garland on the E39 groups on Facebook has one for you, he's breaking a few E39s currently FYI, just needs to make sure that the numbers match :) 

 

As daft as it sounds, lifting the bonnet to see a cable tie holding the valves in place would drive me nuts  - OCD??!!:huh:

 

I've sent the seller a message to see if he has an exchange item.

 

I will try @Tims to see if he can help - sadly don't have a Facebook account.

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Morning gents!

 

Contacted various people on here and Evilbay to see if they had a suitable climate control unit for me. Wasted nigh on a week waiting for answers  - no replies. Seriously, if you want to sell stuff then at least respond to enquiries:angry:. Rant over!!

 

Called a BMW specialist breaker mid week and a second hand unit arrived on my doorstep two days later ( yesterday ). Despite the pouring rain I've just fitted it and hooked up the multimeter to see what the current draw is. With the car in sleep mode I'm now getting a reading of 0.02A, which I believe is acceptable:D. Can someone confirm this?

 

Hopefully not premature and a little early I know , but I think a celebration is called for.........

 

IMG_1420.thumb.JPG.ac619f87581bfe3ce4460464aa9b1f43.JPG

 

:rolleyes:

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Sounds spot on and cheers... 

 

Bought 12 of those the other day whilst in Aldi.

£1.25 a bottle, full strength too... Perfic :mrgreen:

 

Still embarrassed that I sent you a duff HVAC control panel :rolleyes: :lol:

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4 hours ago, d_a_n1979 said:

Sounds spot on and cheers... 

 

Bought 12 of those the other day whilst in Aldi.

£1.25 a bottle, full strength too... Perfic :mrgreen:

 

Still embarrassed that I sent you a duff HVAC control panel :rolleyes: :lol:

 

 That's good value - I'll have to scurry down to our local store and see if they're doing the same:D

 

No worries re the HVAC panel. If it eases your pain give me a shout next time your'e down Lyme Regis way ( about an hour from me), and I'll trundle down and let you buy me an ice cream:P

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