Technical Battery Drain when using climate controls.

[Cailin Rua]

Good afternoon all,

64 plate Fiat 500 Cult here. I'm hoping you can help because I'm really struggling to get to the bottom of my issue...and funds are slowly drying up

I noticed a month or so ago that whilst driving, my battery light would appear on the dash, this would effect my power steering and the steering becomes very heavy. It was always fine when when I first turned the engine on, but would appear a couple of minutes into my journey.

I replaced the battery as I had no history on when the last battery was installed (I've had the car since July 2022) but the new battery did not fix the issue.

I booked it into a garage who charged me a silly amount of money for diagnostics (which showed 'dtc set for short circuit to ground on alternator' but they said they didn't have the light on the dash whilst it was in the garage and had checked the wiring and couldn't see an obvious fault. They checked my alternator and said it was running at 13.7v so wasn't concerned re that.

I drove home, and indeed the light wasn't present. They said they had tightened the battery housing and this may have fixed the problem. It did not, and the light came back on the next day. 2 days later every warning light flashes on my dashboard 'ABS unavailable, Stop start unavailable, Check Airbag, Hill Assist unavailable, ESC' then my climate controls went off, my radio went off and ultimately the battery died completely. I was recovered by my brother, who jumped it and drove it home at higher than normal revs.

Running out of money, I did some research online and it came up with the suggestion of replacing the Earth strap, which we did (and the wire was very oxidised) The problem is still persisting.

I have now noticed a correlation between the climate controls/heating air con etc and the battery light. As soon as I put it on to clear my misty windscreen the battery light flashes up and affects the steering. It's almost as though the heating is draining my battery.

Can anyone suggest what may be going on, and suggest any potential fixes. My brother is very handy with cars and replaced the earth strap easily, but admits he does feel out of his depth with potential electrical issues but it happy to explore any reasonable options.

Any help would be massively appreciated!

 

[steveras57]

Do you know if the garage checked the alternator under full load conditions? its a "smart " alternator and adjusts the charge rate according to load!- the AIR con is a heavy drain system so the alternator may not be working properly and raising the charge rate enough to cope, do you drive at night as the headlights are also a heavy drain system!- does the warning come up if you have the main lights on?!.
Not doubting you but if you have the stop/start system did you fit a stop start specific battery ?as an ordinary one wont have enough capacity to maintain all the systems properly!.

 

[jrkitching]

Hello and welcome to the forum

My first thought is that this could be the very common Blue&Me issue where an internal fault inside the Blue&Me module leads to a permanent current drain which flattens the battery in short order. However, this is usually accompanied by the flashing mileage issue, and that's not been reported in this case.

It's worth doing the following checks:

1) Confirm the car has Blue&Me (IIRC it was standard on the Cult at that time)

2) Check that the Blue&Me is still working properly (play some music from a memory stick, for example)

If it does turn out to be the Blue&Me module, there's a cheap and simple fix - particularly if it's something you're not using and don't need.

 

[A3jeroen]

Rear heated screen in combination with rearhatchwiring shorting out.

gr J

 

[Cailin Rua]

Hi, thank you for your replies.

I have never been able to successfully connect the Blue&Me system, I generally listen to CDs or the radio so this has never been an issue. I've found a YouTube video online on how to remove it, so this is definitely an avenue that I will be exploring this weekend (and really hope that is the culprit) I noticed a lot of people are mentioning the proxy alignment that is needed after the module is removed. Is this absolutely necessary if I'm not replacing it?

I'm unsure if the garage checked the alternator under full load. To be honest, it was a new garage that I chose specifically because they advertised they also dealt in auto electrics and after some research I wondered whether it was a wiring issue between the ECU and the Alternator. Initially I did fit the car with a Stop Start battery, yes

There were a lot of attempts to upsell work that didn't need doing urgently (brakes and discs, oil change etc) by the garage, a few scare tactics and I got a bad vibe in general. I got the feeling they saw a woman in a Fiat 500 and rubbed their hands together. I may be wrong, but I often trust my instincts. The flashing milage hasn't been a feature at all.

I use the headlights a lot (probably too much - I've made a point to stop this) I tend to use them even on grey days. I did switch them on today and it didn't have an impact on the car, but as soon as I switched the heater on - there was the battery light/ restricted steering. There have never been any warning lights relating to the headlights.

I did have an engine management light come on recently, my brother's own diagnostic machine came back with a MAF sensor issue. Not sure if this is connected in any way?

@A3jeroean is the heated screen/hatch wiring shorting out something that has an easy fix? Or would I need to take it to an auto electrician?

Many thanks again, all.

 

[steveras57]

Sorry i wasn't completely clear regarding the headlights by which i meant the additional load might trigger the battery(alternator ) warning light!. the fact that increasing load of headlights + heater might imply that as A3jeroean said the hatch wiring is shorting out the steering issue also points in this direction! you have to be fairly competent at electrics and soldering to consider doing it yourself!as there a bunch (about 15 ) of wires to sort through and repair as needed + the rear wash wipe water tube goes through the same area, repair kits to splice in are available ( about £40) i would think about 2 hours labour at a local garage (about £100 an hour) so about £250 all in!.
The engine management light is another issue separate to this! not expensive to change but you have to be sure its that as other things can cause similar symptoms and the light to come on!

 

[A3jeroen]

Yes. Check the hatchwiring. Info in my Topolino Grigio topic, or in the topic by baglady. It might cause a short circuit when you switch on the rearscreenheater.
I have my dipped headlights on all the time and this has'nt been a problem in the past 33 years of Fiat motoring for me.

gr J

 

[Cailin Rua]

Thank you for your responses. I'm going to investigate these suggestions further and hope and pray that this resolves the issue. I'll report back with a hopeful positive update

 

[Cailin Rua]

Sorry i wasn't completely clear regarding the headlights by which i meant the additional load might trigger the battery(alternator ) warning light!. the fact that increasing load of headlights + heater might imply that as A3jeroean said the hatch wiring is shorting out the steering issue also points in this direction! you have to be fairly competent at electrics and soldering to consider doing it yourself!as there a bunch (about 15 ) of wires to sort through and repair as needed + the rear wash wipe water tube goes through the same area, repair kits to splice in are available ( about £40) i would think about 2 hours labour at a local garage (about £100 an hour) so about £250 all in!.
The engine management light is another issue separate to this! not expensive to change but you have to be sure its that as other things can cause similar symptoms and the light to come on!

Thank you, that's been very informative!

 

[Cailin Rua]

Yes. Check the hatchwiring. Info in my Topolino Grigio topic, or in the topic by baglady. It might cause a short circuit when you switch on the rearscreenheater.
I have my dipped headlights on all the time and this has'nt been a problem in the past 33 years of Fiat motoring for me.

gr J

Thank you for your suggestion. I'll investigate this further

 

[John202020]

Try a jump lead between the battery NEGATIVE and the engine itself and repeat the test even though the earth lead has been done?
Christmas tree of lights suggests rear hatch wiring, does everything on the boot lid work as expected?

 

[GettinBetter]

Try a jump lead between the battery NEGATIVE and the engine itself and repeat the test even though the earth lead has been done?...

This...
Do this first, it costs nothing. A bad earth path will play havock with ALL systems depending on severity of path restriction. The jump lead provides an alternative path. Put the jump lead on and try the aircon again.

 

[Cailin Rua]

Hi. Thanks for your replies. We removed the Blue&Me today. The problem is still present.

I have been driving around with my radio, lights and heater off...and the battery light is still appearing after a minute or so of driving, the power steering becomes heavy when idle.

There have been no issues with the boot hatch opening, rear wiper or parking sensors. Will try the jump lead thing definitely!

The hatch wiring is tidy and secure under the rubber tubing...I'm not gonna lie I am a bit scared to cut the rubber if the wires are all fine underneath, can anyone suggest a replacement if that is the case? Would electrical tape be sufficient?

Many thanks .

 

[John202020]

It's not charging or there's a earth path fault have a auto electrician look at it, not a garage, look up mobile auto electrician?

 

[Derbyfella]

I’ve just scanned this thread….but a couple of simple points from me….if you have rectified the fault previously but the battery is low, then you would potentially still have an issue but be seeing that as the original issue, do you have a charger you could just top up the battery with?

Can you say what the voltage on the battery is, when it’s disconnected? and what the battery voltage is in the car when some load is applied ie the heating system?

 

[Cailin Rua]

I only used the garage I went to initially, because they also advertised themselves as auto electricians, and most feeds I'd read seemed to lead back to potential wiring/ECU issue. My brother admitted he was out of his depth with electrical issues.

The garage weren't able to diagnose my problem, and were keen to upsell me mechanical work that wasn't crucial. They advised me the alternator was running at 13.7v and that the battery light wasn't on (it had literally been on for every solitary journey I'd made in the car before and after that appointment) oddly though, the light didn't come on for my short journey back home from the garage that day.

My brother replaced the earth strap, removed the Blue & Me and after further investigations elsewhere, all electrical tests were coming back fine, I was beginning to run out of options.

I decided to buy a multimeter online.... and the alternator seemed to be the problem after all. My brother managed to replace the alternator and the belt, bit of an awkward job apparently, but the battery light/power steering issue seems to have been fixed.

Unsure why the garage didn't diagnose the problem straight away as the same issue had been getting progressively worse for about 2 weeks before I took it in (even after i'd replaced the battery)

Thank you all for your advice. Thought I'd post an update in case anyone else is having a similar problem.

 

[steveras57]

I only know two things about electricity, Its invisible! and it hurts!

 

[Cailin Rua]

I only know two things about electricity, Its invisible! and it hurts!