Overheating help - No Cooling fan

Hi All,

I have an issue,
Went for a drive today, got home, all seemed ok.

Parked it up, went in, then realised there was steam billowing out from under the bonnet.

I've left it to cool down and been out and had a look over, all seems to be ok.

The cooling fans do not appear to be working. They did, as I tested it, but now nothing at all. it is the dual fan version with a/c. The resistor is knackered on the radiator however I thought that wouldn't effect the high speed running of the fans etc.

Any thoughts? the gauge is reading ok, and the mixture gauge seems to be working ok. I think it did read that it was running rich as I approached home.

Whether I should have not, I removed the resistor on the cooling fan and shorted the blue wire to earth, this powered both fans to full speed, proving:

1. Power supply to fans OK
2. Fans work
3. Somethings not right!

Any thoughts on where to look first?

Thanks.

If the slow speed fan is broken (i.e. the resistor open circuit; have you checked that yet?) then nothing happens until about 102C. That shouldn't be boiling point - the water is pressurised by its own steam and controlled by the pressure relief cap on the expansion tap - but once the engine is turned off, at that sort of temperature, there will still be excess heat which will continue to heat the water. If there's any dodginess on that relief cap - a well-known fault point - then you could both get a steam burst after stopping, and perhaps also when you are driving.

If it happens when you're driving, you probably won't see the steam, and the pressure release will also drop the temperature a little. Though at speed, the system will cool with airflow anyway; the fan doesn't do a lot over thirty mph.

First check though, is the pressure cap - and fix the dropper resistor. If you can't find the right one, you can use something like this: http://www.ebay.co.uk/itm/Aluminium-Clad-Power-Resistors-10W-25W-50W-Full-Range-of-Values-/152059759347?var=&hash=item236777caf3:m:mmh3PY-HrzXEkCbkwwIS0Ug - 0.47 ohms, 50W from memory.

Hi Barnacle,

I have confirmed the slow speed resistor is dead, I have ordered:-
http://www.ebay.co.uk/itm/FOR-FIAT-BRAVO-BRAVA-COUPE-PUNTO-STILO-MAREA-STENA-HEATER-MOTOR-FAN-RESISTOR/172001958403?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I will also order a new pressure cap for the sake of it.

The steam is due to a split water pipe from the turbo.
Any idea where i'll find a part number or a replacement hose?

Thanks

Not sure, James, but you might have a word with Joe (countrycruising) or Nigel (Nigel) who should be able to sort you out. If they're still available as new, then Automotive Autos may have them.

Sorted!

I got a brand new fiat hose and fitted last night, also fitted new resistor and all is great.

In fact, I have a feeling barnacle, I may be emailing you! my next comment will confirm if thats the case.

I have downloaded some software so as I can plug into the OBD port on the car and I cannot get it to work at all,

I have the OBD to OBDII convertor and I have an old OBDII cable i used to use on an Alfa 156 and an old Passat, I also have an ELM327 USB cable that I know works. No matter how hard I try it doesn't connect.

I see talk of the "3 Pin" diagnostic connector, which I have but it only has 2 pin/2 wires, is this correct? it is located by the washer bottle, just next to the AC pump pulley.

Yeah, on a 20vt it's a three pin AMP/TYCO connector, but only two pins are in place.

The ELM327 won't talk to the coupe; wrong protocols. http://nailed-barnacle.co.uk/coupe/startrek/startrek.html will talk (in most cases; there have been occasional failures that I haven't been able to resolve) using an FTDI-based usb-OBD adaptor and an OBD-AMP adaptor. These are still available on ebay, and the software is free.

Note: the software has not been tested by me on W8 or W10; I've used linux for years and don't have the later windows versions available.