131mirafiori forum

Hello, I have managed to locate the clockwatch and the radio wiring to cut them and so avoid battery discharge, as the watch is broken and I suspect it's the cause of battery leak, and because the radio is modern and has memories fitted and maybe it absorbs too much current. I know that I can remove the instrument panel and disconnect the watch, but I don't want to proceed like this because to remove the radio fuse too I should take off the gearbox trim and a seat and this is too much work for such a little issue (the radio is bolted backwards to the dashboard steel panel). I just want to cut the two wires in the fuse box that feed the clock and the radio and to do so I need the colour scheme of the wiring. Does anybody of you have this scheme for a supermirafiori MKIII?
Thank you for your time....

I had this problem with a series 2 131r.  The battery used to go flat in about a week.  I realised there must be a drain & checked out Google as to how to check this with a multimeter.  It was the radio.  Because there is no accessory position on the ignition switch you are tempted to connect both positive (usually yellow & red) to permanent +.  This creates a pulse which is is constantly discharging the battery.  The easy way round this is to trace the ignition + wire at the ignition switch when the ignition is ON & connect your accessory wire into that using suitable amperage new wire as your radio wire will not be long enough. Your permanent + remains as before.  As the ignition circuit is not fused it is advisible to put in an inline 5amp fuse in your new wire.
 Problem solved and the radio turns off on the key.

My radio has memories that would shout down when I turn off the key and above all Is bolted at the backside so I can't gain easy access to the fuse. In any case what I need is a way to identify the radio and clock wires on the fuse box, so I can cut them without dismantling anything.

If you wire it this way you have one wire that is permanently connected to positive so the memories remain.
If somebody bolted it in then you must have room to unbolt it. There are only 7 bolts that hold the dash in so to loosen it enough to gain plenty of access should take no more than half an hour, about the same time as the new wire will take you.  If you cannot spare the time reach under the dash & carefully feel the wires and pull them down, identify the positive & cut it . No need to cut the wires near the fusebox. The next owner may wish to reverse your 'modifications'.

Hi there, from what I can see the clock is powered through fuse number 10 so that would straight forward hopefully....

The only down side is that this also powers the cigarette lighter and some courtesy lights (and possibly the radio if they have used the original "permanent live")

I'll attach some diagrams...

you may want to isolate the clock only which means disconnecting it from the back of the Instrument Panel, it's connection number 11 as below.  That shouldn't be difficult hopefully.

The second diagram shows which other things are on the same fuse so you can trace it through if you want....

and lastly the key for the wiring diagram  ;)  Best of luck

Yesssss! This is exactly what I need, thank you very much. To longhamrob and 131steve: I know how to disconnect the watch and I was the person that placed the radio 18 years ago so I know how hard it was but now I don't want to stay behind the car too much, I have just loosed lots of time a month ago to locate spares and repair the car after a car accident, I need to cope with this without annoying myself further.

If your battery is going flat, don't blame the clock or radio, find the problem. I haven't had a flat battery in 6 years, and my clock and radio work fine. Measure current draw from the battery with the ignition off, if it's excessive, pull fuses until you find which circuit is the issue.

I dont think the owner may be as enthusiastic about his car as others.  As Mick says, it is a very very easy job with a multimeter to find a parasitic electrical drain. Quicker than changing a wheel.  When i tried other (modern) radios before i found my problem, they all created a draining pulse.  When the 131 was new they did not expect to have a permanent memory supply to the radio as they were push button tune so far as i can remember. 

I'm not blaming radio or clock blindly, I have a 25 year experience with this car, so I inmediately found checking fuses where the leak was and kept away the fuse number 10. As my clock is broken it's probably here the issue. Also the radio is just 18 years old and has electronic memories, so here we have another candidate. The rest is internal lighting (it's ok) and cigarette lighter, and electric antenna which is ok too. I could measure current draw using a multimeter but it was not necessary: just removing and reputting in place the single fuse I could see the spark and detect electricity leak. Now, the car stayed a week without the fuse and with battery on and it's perfectly functional, so I think I was right.

Thats a very long time you have had the car.  Apart from that 1 owner U.S.A  Fiat brava you could be one of the oldest.  Have you not got a radio now?

great info contained in these posts
the battery in my 131 sport was draining after 4 or 5 days,had to disconnect the battery every time
a real pain hopefully now i might get to the bottom of it
what a great site
 :) :) :)

Radios with station memory take very little current so not likely to be the cause of battery drain. But modern radios with Bluetooth take a lot of current! I fitted such radios in both my Lancias and they would drain the battery in a matter of days.

I confirm that the leak was from fuse 10, the battery is still good after ten days without this fuse. the radio has been fitted in 1994, but has almost not been in use because of the removable front that I never take with me. I just feel the need of a radio when I drive alone which is not usual. The car is still in daily use as ever, so I need it to be pain free. I could remove and replace the watch but really not interested in it. The radio has some issues, as cassette player only sounds in left loudspeaker, AM switch is not running and tuning is not easy, so maybe it leaks current too. If it was not so painful remove the radio I'd have yet it done.

Just add that I checked all users with a multimeter and these were the results: watch no leaks, lighter no leaks, inner lights no leaks, radio just leaking 36mA, which seems to be ok to keep memories on. Now, how can a 36mA leak drain a 45Ah battery in 10 days?

It just does.  Good job finding the leak.  Excuse my correction but a watch is a timepiece worn on the wrist (mostly).  I think you mean clock.
Should you change your radio & you still have the correct size aperture (which even to this day remains the same size), your new radio will come with a sleeve that locks your radio in place. Thats it. There is no further fitting required. Since all radios seem to adopt the same wiring loom these days you could upgrade or change radios in the future within 60 seconds.
In my own car, in view of the increased weight of modern cd players, i have put a matchbox sized 3mm piece of rubber directly under the radio that rests on the bottom of the dashboard to stop any chance of it rattling or making the cd jump.

My english is spotty so don't take it too seriously. The radio has a custom rubber seal all round to avoid rattle and give good finish. In these days radios were retractile and had an iron drawer to go into. Now there are aluminium cases that are smaller and have not the same fitting. Anyway, it seems normal to leak 36mA to keep memories, so maybe I should shift to an old radio with no current drain when tuned off.

36mA is a bit much just for memory storage in a radio but not by much. I would expect 10mA to 20mA.
36mA will drain a 45Ah battery in about 50 days but if your battery is not new it may drain in about 10 days?
Have you done a battery drain test at the battery to see if anything else is drawing current or do you have just 36mA drain at the battery terminal?

The 131 radio aperture (with all the original radio fittings removed) is not DIN-E standard. DIN-E or DIN 75490 (later ISO 7736) was not adopted as an international standard until 1984. The 131 radio apertures are considerably bigger so the modern aluminium frames for radios don't fit very well and don't hold the radio units in place well.  

Thats interesting and very specific but the radio aperture on my 1979 series 2 is good as damm it the same as standard 'din' apertures of today. My other 1981 car is the same. My cd player sits perfectly on both cars.
Regarding the current loss it is common knowledge in the car hi-fi world that modern radios have a noticeable current draw but when wired up with a permanent AND accessory positive i.e 2 sources you will not have a problem. This was not an option on a new 131.

I'll check the fuse number 9, the third from the left, that's the only one with number 10 that remains permanently wired to positive, and electric window and central locking fuses that are apart.

No leaks from radiator electric fan nor from horn. I think I need a radio without electric memories. Does anybody know if there are such radios with simple an classical aesthetics i.e. no coloured digit screen and with no blue led face?

I'm sure with a bit of homework you'll find something closer to home.
http://www.vintagecarradio.com/store/index.php?cPath=20_54&osCsid=2270a0e2765ad311bb1d83a7ee245759
These probably still use power for memory. You need an old push button radio for your station preset channels.

Fiat did an oe push button radio did they not?

But most cars have radios with memory without a problem. You need to check current drain at the battery so you know the total current been drawn when the car is sitting unused. If it's just 36mA and your battery goes flat in 10 days then change your battery and not the radio.

It is not the radio memory that is causing the problem. It is the accessory wire being constant live. It is not expected to have a continuous supply.

What do you mean by it's the accessory wire being alive? Radio has no separate wire for memory and power, so if connected will ever leak 36mA. I measured the leak at fuse num. 10 and this was the only leak, fuse num. 9 shows no leak and others are not feeded when key is off. I can check directly the battery, but I think I'll find 36mA again.

In effect, 45Ah divided by 36mA is just of the order of 50 hours as stated in the previous page. So I'm doubting the battery is not good, although it's just six months old.

Most modern radio units have two "power" connections. One is meant to be live all the time and provides power for the memory functions. That's radio stations, CD track and position, mp3 list track postion etc depending on the functions. The second "power" wire is the one that actually makes the unit work and that's normally connected to the accessory position of the ignition switch so that if you want to listed to the unit without the ignition being on you switch the ignition key to "Accessory". When wiring such a radio with two power wires in a 131 which doesn't have an "Accessory" position on the ignition, the common practice is to connect the two power wires together and connect them to the single power wire for the radio provided in the 131. But I don't think that's your problem unless you have a very modern unit with Bluetooth that will draw about 200mA.


I think you meant 50 days and not hours?
That's what I think too. If your only drain is 36mA and your battery goes flat in 10 days then it must be the battery. Even if it's only 6 months old it may have been faulty by the time you bought it (was there a manufacturing date on the battery?). It's also possible that the battery has been damaged by being let to drain and leaving it flat for several days or weeks before recharging it. I 'killed' the battery in my Gamma that way due to the Bluetooth radio. The battery would go flat in a matter of days and over the winter because I didn't use the car I let the battery flat without recharging it so in 9 months it was dead. But I managed to get a free replacement under warranty  :D. I've now re-wired that radio so the "accessory" wire is switched by the ignition which means I can't listen to anything unless the ignition is on. I've also taken wise advice from Simon's book and disconnect the battery when I put the car in the garage and don't expect to use it the next day.
But before you go out and buy a new battery, check the current drain at the battery to be sure. There are circuits which are not fused and there may be other wiring faults which would draw current not detected when checking at the fuses. If you just have 36mA at the battery then it must be the battery that's at fault.

Yes 50 days I ment. Maybe it's the battery, I'll check directly at the poles and if it gives 36mA again I'll sentence it to death  ;D (I have already checked the alternator and it works and charges the battery).

if replacing your battery, look for one with something called "glass mat technology" they are fitted as standard in BMWs. i can leave my cars for 6months over winter, never had a problem,   i have a collection of mk3 dash binnacles if you want another clock, as for radio wiring, on r.h.d. mk3's follow the reversing light wiring from the trans mission tunnel under the carpet accross the floor to the pedals. you will find two unconnected wires (no idea what they are for but not used on uk spec car) connect in to the orange&white  one and use this to power the radio, use the red pemanent live wire to power just the memory as has already been posted.

Thank you for your helpfullness but I'll just let the watch as is.. the wiring you refer is in case an automatic gearbox is fitted, which is not your case as I can see.
Regards  ;)