MG-Rover.org Forums banner

21 - 34 of 34 Posts

·
Registered
'06 MG ZR +120 (HQM) '04 MG ZR 105 (IAB)
Joined
·
9,366 Posts
...slightly bigger electrical changes than connectors used..... (YWC001541(?))...
Interesting list of differences, I was aware of some of them, but not all.

The 'Chinese' engine ECU was manufactured by Continental (the MGR one was a Motorola IIRC). Did the TF not get a battery-backed-up alarm sounder when the ZR/ZS did in 2003?? (at the same time that the Pektron SCU was first fitted).

Glad we seem to be getting closer to the source of the drain - I would certainly check the operation of the door/boot switches for the lights as these are linked to the locking system, and the way the interior lights operate means there is a possibility of a light remaining powered, even though it may not be sufficient for it to glow.
 

·
Registered
mg_tf
Joined
·
414 Posts
Very interesting.
‘....After 18minutes. ...to go to ‘sleep’....’
I would never have expected it to take that long.
 

·
Registered
'10 TF135
Joined
·
338 Posts
The 'Chinese' engine ECU was manufactured by Continental (the MGR one was a Motorola IIRC). Did the TF not get a battery-backed-up alarm sounder when the ZR/ZS did in 2003?? (at the same time that the Pektron SCU was first fitted).

Hi Man in the Car.

No I don't think it was a Pektron initiative because it was not on the 2005 TF I used to own. On that car I was able to use the car battery isolator to turn it off (and it was made in March just before prod was stopped...)

Yes SAIC (NNN000830) is Continental and yes MGR (NNN100743) was Motorola - but currently-offered-brand-new TF ecus are now Continental (part no.NNN100743), too, from Rimmers.

And back on topic I agree with suspecting switches but also think the dreaded hinge wiring loom problem might feature somewhere too?
 

·
Rover Lifestyle
Rover 200 Rover 600
Joined
·
12,819 Posts
In accordance to wiring diagrams MG TF 2004-2005 have batery backed up sounder for alarm. Why your car did not have it is someth8ng to see, but it might be taken out at some point.
 

·
Registered
Joined
·
1,128 Posts
Thank you all, gentlemen;



Mark,

Interesting info from MGR Tech Tip, the car with fuse F5 removed is well within limit at 17mA.

We have three 12v to USB adaptors for various purposes and I only checked one of them previously. The other two are now checked and showing no continuity internally. As from next Tuesday we will only have two, once the bin men have been. Sorry for potentially misleading you.



Austin,

The car is, or was, my wife’s 16-mile e/w daily commute to work before lockdown started last year, since when she has been working from home so the car gets little use. The battery drain was first noticed about three weeks into lockdown. A return to the office might be announced any time soon so that has concentrated my mind to sort the problem.

Thank you for prompting a long overdue sanity check.

With bonnet up, bonnet switch disconnected, car shut but not locked there was a draw of 70mA

Withdrew fuses one by one, F5 was the only one to have any significant effect, draw reduced to 17mA

This led me to fuse 23 which when pulled had no effect on the draw, still 70mA

Conclusion, there is a fault within the central locking system. Never having had any involvement with C/L I’ll take a stroll through the posts on this forum for clues as to what to look for next.



Julian,

I would thoroughly recommend that you get your hands on a ‘cheap and cheerful’ multimeter so that you can go through the fuses in a logical manner and quickly identify the defective circuit without waiting a week between checking each one. (Please forgive me for sounding a bit like the Pot calling the kettle black).



Adam
Hi Adam. No problem. You are right in your observation. I do have a multimeter but I am taking the lazy route.. (which probably takes more time than if I did the job properly).
 

·
Registered
Joined
·
26 Posts
I too have been following this with interest as I thought I had a parasitic drain on my TF last autumn. I ended up buying a battery isolator and have had no problems since. The current drain with everything shut down but car unlocked was 27mA so looks to be near the official figure.

Jon
 

·
Registered
mg_tf
Joined
·
414 Posts
Hello Jon,
If you thought you had a parasitic drain because your serviceable battery was draining in an unreasonable period time, then you had/have got, a parasitic drain. Obviously, that’s all the isolator is doing is ‘disconnecting’ the battery, so that parasitic drain cannot occur. It isn’t a fix, but only a dodge around an issue.
You say you have a within-limits drain of 27mA so all is well? But you say this is when the car isn’t fully locked down, so that reading obviously isn’t meaningful.
Kind regards,
Austin.
 

·
Registered
Joined
·
26 Posts
Hello Jon,
If you thought you had a parasitic drain because your serviceable battery was draining in an unreasonable period time, then you had/have got, a parasitic drain. Obviously, that’s all the isolator is doing is ‘disconnecting’ the battery, so that parasitic drain cannot occur. It isn’t a fix, but only a dodge around an issue.
You say you have a within-limits drain of 27mA so all is well? But you say this is when the car isn’t fully locked down, so that reading obviously isn’t meaningful.
Kind regards,
Austin.
Hi Austin
Appreciate that the battery isolator is a dodge, however was at the time out of ideas! When you talk about the car being locked down, how is it possible to measure the current drain on a locked car as when you open the bonnet surely the alarm would go off?

Jon
 

·
Rover Lifestyle
Rover 200 Rover 600
Joined
·
12,819 Posts
When you talk about the car being locked down, how is it possible to measure the current drain on a locked car as when you open the bonnet surely the alarm would go off?

Jon
Only thing you need to do is to press the switch and keep it pressed in order for car to thinks the bonnet is closed.
 

·
Registered
1995 MGF Mpi
Joined
·
842 Posts
Both of our early Fs' batteries will go flat if left unstarted in about 3 weeks time and this is with the alarm not activated. I have not gone through pulling fuses but it is the next thing that I should do.
 

·
Registered
mg_tf
Joined
·
33 Posts
Discussion Starter #32
Jon & Jon,
Open the bonnet and prop it before locking the car and disconnect the single wire to the wee switch, or ease the switch up and wiggle it out of the hole in which it lives. It is a 'switch to earth' arrangement so by removing the switch from its mounting the car will think the bonnet is shut and the light (if fitted) will not come on so you can lock the car and carry out tests with the bonnet open and propped..

I have checked the dreaded hinge wiring loom problem, stripped back loom insulation and did visual inspection of all wires, there was no problem in that area,. The alarm 'siren' is also removed because of corrosion of internal components, battery drain persists.

I have applied a more logical approach and have found the following:
with all fuses in place, after about 10 minutes of locking the car, drain was sometimes 50mA, but most times 70mA
with under bonnet fuse F5 (CDL/Alarm) removed drain was 17mA
re-fitted fuse F5
F5 feeds CentralDoorLocking directly and Alarm through in cab fuse 23.
with fuse 23 (alarm) removed the drain was 70mA

This leads me to believe that the fault lies within the component, or connection to the component that receives the signal from the blipper. I have absolutely no idea what that component is, what it looks like, or where in the car it is located.

Any clues would be thankfully received.

Adam
 

·
Registered
'10 TF135
Joined
·
338 Posts
Silversloth, the security control (scu) unit is what the remote talks to, and it's this little black box in the (passenger side) pic - with wires leading into it - actually behind the heater knobs.
You take off the sides, where the footlights are, to extract it from its cradle (I found two 'tamper-proof screws, tho', with five-point hollow fitting...)
Inside it there are electrics + 5 relays, a couple (I think) of which control locking.
They're poor quality and may need upgrading - (google 'Technozen' for info; he's upgraded mine...) - and he can check the rest of the scu.
 

Attachments

21 - 34 of 34 Posts
Top