Cooling Fan - to work or not to work

[Shant Fabricatorian]

Having trouble with an intermittently-working cooling fan. Sometimes it will come on normally, other times it lets the engine run very hot, near the red before I switch it off/get moving again. Before I go underneath it tomorrow morning (bye-bye Saturday) does anyone have any ideas about what to look for specifically? I'm thinking maybe it's just gunk in the connections, or perhaps the thermal switch is on its way out? Or, more expensively, maybe the thermostat is in need of a replacement?

[Will]

First, check that it GROUNDS when hot. Then work your way back thorugh the system. I don't know what it is with coolant temp switches, but occasionally they just start acvting up. Other times, it's the relay spade connections, or even the fan connector or fan itself. I would most likely replace the coolant sensor for good measure if in doubt, and also add an override switch, which I have done in all my Lancias.
Of course, that didn't help the last time I had a problem because I blew the fuse for the circuit my override switch was on, so I made a quick jumper between the fan and headlight, and thus could turn the fan on or off with the headlight switch.
PITA that whole cooling system- worse I think on the Coupes than the Monte, if I recall correctly the coupes use a ground to that ^#^^& connector up behind the headlights, that "starfish" shaped thing- whose contacts always corrode so horribly.
-Will

[Hamish]

I have to concur with Will on this one - the essential modification that I think every Beta owner should make is an overide switch for the cooling fan, it's a real must do and takes twenty minutes. Mine was set up quite simply by cutting into the supply and earth feeding an auxiliary switch on the dash. There was an in line fuse fitted to save anything getting a tad too hot :!: Those twenty minutes fitting could save your engine.
The thermostats are generally reliable, but easy enough to pick up if you're in the least bit concerned. It's worth checking it out. Have you actually flushed out the whole system :?: It's a worthwhile exercise, make sure you disconnect and flush out the pipes that provide for the heater matrix at the back of the engine.
If anything in the rest of the system is suspect, it's the waterpump. Put simply they provide marginal dispersion at best :roll:
Another worthwhile conversion is the 'in head' thermostat conversion Guy Croft mentions in his book. I did it on a Spyder many moons ago and there are benefits but it takes time and patience to do.
Hope this helps :wink:

[Shant Fabricatorian]

Thanks for the tips. Here's a progress report:

Tried cleaning the grounds on the thermoswitch and the earthings just behind the headlamps - no luck. Checked the relays by substituting them with the horn relay - all fine. Ran the fan directly through the battery - it worked. Good news. Connected the two wires from the thermoswitch together and switched on the ignition - no result, which says it's not the thermoswitch which is the problem. In other words, the problem lies with an interruption of the current between the battery and the fan. I was pretty hot, tired, dirty and frustrated by this stage, so I said I'd try again tomorrow.

What I have managed to narrow it down to is a loss of current somewhere between the blue and black wires leading to the fan itself, and the thermoswitch. Part of the problem is that the wiring diagram which I have doesn't correspond exactly with what happens to be in the car, coupled with the fact that a whole load of wires are just lumped together with electrical tape (therefore making it impossible to determine exactly what goes where without unwrapping it). That's the next step - I was rather hoping I wouldn't have to do that, but it looks inevitable - I just have to find the time. I bet it's either a loose connection or an earthing buried somewhere deep in there. I think I'll take your advice and add an override switch when I get a chance as well.

The good news (!) is that it's stopped working intermittently and now doesn't work at all, which makes it easier to trace and therefore fix.

The Beta's been dauntingly reliable over these past few months, so I suppose it was only a matter of time before something new broke. Anyway, I suppose it's better it happens now than when I head down to Canberra for AutoItalia in 3 weeks or so...

[Shant Fabricatorian]

Further to last progress report, I decided, after seven unproductive hours over two days, to have one more look at the fusebox, just in case I'd missed something (actually the real reason was because I didn't fancy getting involved in aforementioned mass of black tape and wire, at least not yet). And sure enough, I found the culprit - not a blown fuse, but one with a hairline crack. It also explains why it was earlier failing intermittently - occasionally the crack was being covered up, but then a bump in the road probably put it out of business for good.

I don't trust my own electrical skills enough yet to put in an override switch (and risk the whole lot going up in flames) - even though they are getting better, the Beta forces you to improve - so it was packed off to my mechanic. In exchange for the really quite reasonable sum of A$120 (about fifty quid) he junked the existing fan wiring system and replaced it with new wiring, in addition to adding the override switch. I can now sit in traffic jams with confidence...