Hi,

Because of some alternator problem of my car, the battery was left disconnected for weeks. The alternator has been changed recently.

After reconnecting the battery, I noted:

- an unsteady idling (the revs drop until the motor almost extincts itself but then the ECU kicks in and makes the motor rev again, only for it to slow down again shortly after...)

- for some minutes during initial driving, the motor idled for some times making some intermittent knocking noises

- some kind of "sudden loss of power holes" appeared which means that the motor has sudden misses - as if somebody turned the ignition of for a fraction of a second - this happens only in the partial-load operational range. I never yet experienced these "sudden holes of power loss" when driving with the accelerator at the floor...

- I cleaned the injection system with some additive - to no avail. However, during the time the additive was in the fuel tank, the above effects occured rarely.

- fuel consumption dropped to a magnificent 43.58 MPG (UK Gallons) which is 6,48 l/ 100 km (corresponding to a theoretical range of 489 miles not too bad for a Fiat bravo 55 kw 1,4 litres 12V which normaly needs 20 percent more fuel.

those sudden power losses are quite annoying on the autobahn. It only happends for a fraction of a second, but it happends repeatedly and seems to happen more often now...

before the old (faulty) alternator gave up, there was some problem with voltage which triggered the airbag light and let the battery sputter out acid with a fast rate.

The motor had been running too rich during about half a year before because of a defectuous thermostat (which was open all the time cooling way beyond the need).

by the way, on the first drive after the new alternator was fitted, I smelled something burning and some minutes afterwards, the 20 A wiper fuse blowed, it keeps blowing since - I have to wipe the car by hand...

Any ideas what's going on now?

have you checked the voltage at the battery is correct, so you know the alternator is working ok? is your new battery the correct rating for the car?

i think your wiper circuit may have been damaged when the alternator was previously faulty and overcharing the battery. fingers crossed replacing the electrics on the motor will fix it and the burning smell wasnt a damaged wire frying itself.

I did not replace the battery. Voltage at the battery is about 12,2 Volts with the motor off. With the motor on, it's 14,2 Volts... it stays at 14,2 Volts even with headlights etc on.

The very next thing I'll do is dismantling the cover of the passenger air intake to get access to the wiper motor, so I can measure resistance and inspect the cable, starting from it's connection with the wiper motor... With some luck, I will at least find the fault for the wipers not working. Maybe this is connected with the motor problem...

if the battery was losing acid it means it was overcharging, which seriously reduces the capacity even though the voltage is fine. replace it.

Jug, I do not think it's the battery... the car starts fine. I tested the battery, and there was no need to fill her up with water. I mean, there was some acid spilled out, but apparently only when I tested the car. I did stop the motor immediately. This was before I disconnected the alternator. The car started and worked well with the old alternator disconnected, I even did go to town with it and buy some lunch... Now there is an (almost new) alternator fitted, which works fine. I did some charging voltage tests, too...

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Update: There a two problems left: Randomly, the car would die while idling. I did not experience "lean holes" recently. The other problem is, the 20 A fuse of the wiper motor circuit burned out. So today, I tested the wiper motor.

There is a plastic case next to the wiper motor which electronic circuitry in it and three contacts going to some circular metal disc (which, by the way, was full of protecting grease). I did clean it a bit.

The circuit board has 4 connectors as input and 3 connectors as output going to the wiper motor, which connects with 3 wires.

With ignition off, and the wiper motor still connected, I tested the resistances of the 4 connections of the plastic wiper case. From left to right, I numbered the wires as 1,2,3,4:

from 4 to 1 or 2 or 3: no conductance
from 3 to 2: 2,3 Ohms, from 3 to 1: 1,1 Ohms, from 3 to 4: no conductance
from 2 to 1 or 3: each 2,4 Ohms. from 2 to 4: about 40 Gigaohms (this means no conductance)
from 1 to 4: 40 Gigaohms (no conductance)
from 1 to 3: 1 Ohm
from 1 to 2: 2,4 Ohms

I disconnected the wiper motor to measure the voltages of the 4 wires leading to the white plastic case of the wiper motor unit with ignition on, the voltages are:

Wiper stalk in the upper position (interval mode) : 0 V - 0 V - 12 V - 12 V
Wiper stalk in the off position: 0 V - 0 V - 0 V - 12 V
Wiper stalk in the first lower position (continuous mode): 0 V - 0 V - 12 V- 0 V
Wiper stalk in the second lower position (fast continuous mode): 0 V- 12 V - 0 V - 0 V

Motor wires: there a three wires, green, red, brown.
Measured while the motor was disconnected:
Between green and red: 6 Ohms
Between red and brown: 6 Ohms
Between green and brown: 0,85 Ohms

Voltages of the output of the circuit board (connection for the motor) : left(brown) - middle(red) - right(green), MEASURED WHILE THE MOTOR WAS DISCONNECTED:

stalk in upper position: between brown and red: about 0,3 Volts
between brown and green: about 0,3 Volts
between red and green: 0 Volts

stalk in off position: between brown and red: unsteady 6 Volts
between brown and green: 12 Volts
between red and green: unsteady 6 Volts

stalk in first lower position: between brown and red: unsteady 6 Volts
between brown and green: 12 Volts
between red and green: unsteady 6 Volts

stalk in second lower position: between brown and red: 12 Volts
between brown and green: about 0,3 Volts
between red and green: negative 3 Volts

Maybe the motor is not entirely in its resting position. Wipers were about 2-3 cm higher than normal.

Measuring the motor current:

I disconnected the red (middle) wire. The green wire was connected to its corresponding output of the circuit board, the multimeter connected the brown wire to its corresponding output of the circuit board. So the motor was going red + brown. With the stalk in first lower position, the motor took 14 Amperes of current, the casing did very slightly budge (about 2 mm) but the motor did not make any sound nor did it move the wipers. This was with the engine off, battery voltage under load was about 12,0 Volts.

With 0,85 Ohms of resistance between brown and green, the 14 Ampere were to be expected. With 14,5 Volts (engine running, alternator charging) the motor would take 17 Amperes in normal mode! Ok maybe it takes such a high current because something inside blocks it from moving. I dont know. I'm just wondering that if the wiper motor takes 17 A in normal mode, how much will it take in fast mode? It is secured by a 20 A fuse, and there is the electric pump for the window washer liquid in parallel. So does the motor take too much current? Is it broken? Is the 0,85 Ohms of resistance too low? Or was this already the "Fast mode" wiring?

It's a Magnetti Marelli wiper motor, TGE 134 A 12V, 17368 0333

So now I have disconnected the motor and put a new 20 A fuse back in.

By the way, I discovered that this motor is water cooled on demand This must be a very special fiat model. Actually, I was wondering why there was some loss of pressure for the windows washers. But look for yourself, I took some short mpeg video of it which I have put on my webserver. Right-Click on the link and save the destination of the link, then open the downloaded file with power DVD or an other mpeg player. The download should take about 20 seconds, its a 28 MB file. If you click directly on it, the computer may display "page not found", this is a standard response of my web server since there si no html document associated with it... the mpeg file will nevertheless be loaded in the background. Just be patient...

replace the motor's electrics, its that "plastic case next to the wiper motor which electronic circuitry in it". its a common problem.

water cooling isnt a good thing

Hm, it's difficult to find only the electrics. Most of the time, they come with the motor attached.

The original motor is Magneti Marelli TGE 134A.

However, when looking up scrap yard data on the internet, it seems other Bravos do feature an other type.

I've seen a Bravo 1.8 16V GT 1996 which features a TGE484A.

Even more confusing is that the official Magneti Marelli document states that there are two motor types for all Bravas/Bravos, TGE 208 L and TGE 434 Q. Please have a look at the pdf here.

My car is a 12V 1,4 l bravo.... 1996 I believe. Unfortunatly, the TGE 134A does not show up in the replacement lists.

As far as I understand the document, all front wiper systems can be replaced by TGE 208L, so this would mean they are all the same?

@ jug: you think the wiper motor is alright? Shouldn't it run then, when I apply current (ok current went through the circuit board, I didn't apply it directly) Is it a DC motor, or is it AC? Because if it's DC, it should run if connected directly to battery, shouldn't it?

yeah motor is DC and should run continuously at full speed if connected directly to 12v.

i would expect the TGE 208 L to be suitable for fitting to your car.

I got the same wiper motor today (electrics included) a TGE 134A out of a scraped 2 l HGT from, I believe, 1995. It was about 66 Euros. Unfortunately, the car they took it from had already 122 000 km on the clock. Even if it's exactly the same model, this wiper motor has different resistance to mine: from contacts 1-3 its 2,2 Ohms instead of 0,85 Ohms. I believe my motor has a short inside, that's why it has such low resistance and high current but won't budge. I'll change it tomorrow.

The meager holes have almost entirely disappeared, consumption is back to normal again with about 7,1 l/100 km. In summer, she always needs between 7,1 and 7,2 l /100 km. The car still cuts out on idling sometimes, but will start immediately afterwards. Maybe it's some loose connection somewhere...

cutting out at idle on the 1.4 is often spark plugs or HT leads or a dirty throttle case.