Twingo - electricity shorting

[lashie]

Terve kaikille

I just thought I'ld try a posting, my Finnish isn't up to it just yet - really sorry, I need a few more years!

My 1999-2000 Twingo has problems with electrics just now.

The symptoms are:
Blown front left seisontavalo. Power is ok. Replace bulb but blew instantly.
Blown front right seisontavalo. No power. Signs of burning to bulb holder.
Not working back right seisonvalo. No power.
Heater fan works on only top setting ,4, not on 1,2,3. (that's the weirdest thing)
Heater light not working (havn't checked for power)

All fuses have been checked inside the car, and are ok.

I have a Haynes book in French, but what I don't understand, before I go looking for an 'earthed' connection is why the fuses aren't blowing.

Any tips for tracking this would be really appreciated. The heater fan is the strangest thing, since it runs on a single circuit. It seems that all the settings that have a resistor no longer work. I wonder if they have blown too?

Any thoughts are hugely appreciated.

Terveisin
Dave

 

[Juha™]

Vs: Twingo - electricity shorting

Terve kaikille

I just thought I'ld try a posting, my Finnish isn't up to it just yet - really sorry, I need a few more years!

My 1999-2000 Twingo has problems with electrics just now.

The symptoms are:
Blown front left seisontavalo. Power is ok. Replace bulb but blew instantly.
Blown front right seisontavalo. No power. Signs of burning to bulb holder.
Not working back right seisonvalo. No power.

Terve Dave, and welcome to the forum!
Don't worry about the language, it'll come to you in 25-30 years! Being the easy to learn language that Finnish is...

So you checked the power/no power with a voltmeter, i.e. 12V reaching/not reaching the bulb holders?

The fuses not blowing is not so strange after all. If you get a really bad short (a wire-melting bad i.e.) then the fuse should blow, but if it's just "slight sparkling" then the current might not reach high enough levels for the fuse to blow. A single 5W light bulb actually has a much weaker filament in comparison to, say, a 10-15 Amps fuse, so the bulb probably blows first acting as a "fuse" instead.

From looking at the Haynes manual it seems the LHS and RHS side lights both have separate circuits and fuses:
LHS front + rear = 1 circuit
RHS front + rear = 1 circuit

Based on that, the problems on the left and right MIGHT not be directly related. So let's look at the LHS first:

Does the rear side light on the left work? If it does, are you sure its bulb isn't in the wrong way around? The rear bulb is a 5/21W double filament bulb, the 5 watt filament being for the side light and the 21 watt for the brake light. Now, if the bulb's in the wrong way, you get a side light working at 21W instead of the supposed 5W. If that's the case, then when you connect a lower wattage 5W front sidelight bulb parallel to this 21W bulb, the weaker 5W bulb is bound to blow. That's because the amperage the 21W bulb draws through the circuit (thus also through the 5W bulb located in the same circuit) is much greater than what the tiny front bulb can handle.

So first I'd check the LHS rear side light isn't shining too brightly, i.e. the light should become brighter when you step on the brakes. If it doesn't brighten up, then the bulb almost certainly is in the wrong way around and you're on 21W all the time.

As for both the left and right hand sides, I'd also check the + and - terminals in the bulb holders haven't been bent/dislocated and are not touching each other, causing a short. The burned bulb holder on the left front might indicate a short there. Also check the glass socket bulbs themselves, they also have fine wires for + and - that might bend out of shape.

I'd also remove all four of the side light bulbs and then test each corner first on its own without any of the other three bulbs, helps isolating the culprit.

If you have an ohmmeter you could also test for continuity between the bulb holders' + and - terminals. With the lights OFF, there should be NO continuity between + and -. If there is, then there's a short somewhere.

Heater light not working (havn't checked for power)

Interestingly, this is in the same circuit with the LHS side lights so might be a related problem...

Heater fan works on only top setting ,4, not on 1,2,3. (that's the weirdest thing)

Any tips for tracking this would be really appreciated. The heater fan is the strangest thing, since it runs on a single circuit. It seems that all the settings that have a resistor no longer work. I wonder if they have blown too?

I'd strongly tip on the speed-limiting resistor box being faulty. I haven't looked into its circuit more closely, but besides the resistor wires there is a diode: Maybe the diode has burned causing the "restricted" speeds not working.

A burned operating switch or its connector are also known to "lose speeds", but usually it's only one speed missing or then all of them. Only the highest speed working seems a bit too "convenient", so I'd still tip on the resistors/diode.


Can't think of anything else at the moment, hope this gave you come ideas.

 

[lashie]

Vs: Twingo - electricity shorting

Wow, great reply, thanks for the help!

I parked in a heated car park and went back after half-an-hour armed with new 5w bulbs. I then rechecked the fuses, the right side parking light circuit fuse was missing, as it had been the night before. I checked the footwell for it having dropped. I replaced it and replaced the front parking light bulbs.

So it worked. I have a suspicion that the wet weather before Christmas break, then the freezing over the last week caused a short somewhere on the left hand circuit. The right hand circuit, with no fuse is a mystery to me.

The heater motor, as you say, seems to be a resitance problem. It may be the motor dieing, meaning not enough air is passing over the resistors when they are all glowing red hot. I found a bunch of stuff on a french site:

http://www.forum-auto.com/pole-technique/section12/sujet265134.htm

So, I'll have a look today. I think it'll be fairly clear once I pull get the thing yanked out.

Thanks hugely for your help! ;D

 

[lashie]

Vs: Twingo - electricity shorting

Heres the resistor pack. I think it may be the thermal fuse. There is no current across the fuse, but maybe thats the way it should be ? There is a current across all the other resistors.

What do you guys think.

 

[lashie]

Vs: Twingo - electricity shorting

...got a new part from Autopaasi (sp), it was the thermal fuse that had blown. I got a second-hand part in from an Autopurkamo up north, but that also had a blown thermal fuse.

I'll install it today, I've got the airbag discharging at the moment.

Thanks immensly for your help Juha, great to know that you guys are around when things get tricky!!

I am thinking that the there may have been some kind of an electrical surge in the car that blew both these circuits at the same time. See what happens!!

By the way, if anyone needs to info from a Haynes for Twingo II or III, let me know!