Poxhall Zafira, fan running on/battery drain

[uk_senator]

Went to try to sort out one of my mates wives motors this afternoon, had a dead battery. Went & jumped it & she mentioned the fan was on when she left it yesterday which she doesnt recall it doing before.. Think it would do it when I was there? 

No warning lights, nothing on the diag, cleaned as many connectors as I could reach (none seemed corroded though). let it warm up, fan was cutting in & out fine, went off every time I restarted it (about 15 times). Only thing was, the AC fan wasnt coming on with the A/C at all, but both were coming on with the cooling fan.

I`ve since googled it & there seems to be a multitude of issues & muchos compexitios in the fans circuitry.. 

Why? Why is there 2 fuses, 6 relays, 2 sensors, a cooling fan ECU AND the circuit runs through the main ECU.. Why?!? What an absolute arse of a system...

She called me 10 mins ago, its dead again.. I told her to buy a new one & throw the Zafira in the nearest skip. 

[SiC]

I don't know the Zafira, but I know the Astra G which are the same platform and nearly identical electronically. The older ones had a Cooling ECU that was removed in later models with the fan control function done by the engine ECU.

 

The ones with it, if the Cooling ECU detects a major fault, it will leave the fan's on. The only real two major faults are loosing Coolant Temp sensor (either dodgy sensor or damaged wiring - there is a replacement wiring harness from Vauxhall for this) or alternatively if the Cooling ECU looses communication with the engine ECU.

 

In the last case, it's also possible that's happened as Vauxhall put the cooling ECU behind the bumper, where it can get the connector wet and corrode. Disconnecting and spraying with electrical contact cleaner should help.

 

Ideally get the codes scanned by a Vauxhall specific code reader. A knock-off op-com should do it, or if you have a ELM327 adapter, the app "Scan My Opel" for a couple of quid from the Android App store will do it too.

[uk_senator]

I don't know the Zafira, but I know the Astra G which are the same platform and nearly identical electronically. The older ones had a Cooling ECU that was removed in later models with the fan control function done by the engine ECU.

 

The ones with it, if the Cooling ECU detects a major fault, it will leave the fan's on. The only real two major faults are loosing Coolant Temp sensor (either dodgy sensor or damaged wiring - there is a replacement wiring harness from Vauxhall for this) or alternatively if the Cooling ECU looses communication with the engine ECU.

 

In the last case, it's also possible that's happened as Vauxhall put the cooling ECU behind the bumper, where it can get the connector wet and corrode. Disconnecting and spraying with electrical contact cleaner should help.

 

Ideally get the codes scanned by a Vauxhall specific code reader. A knock-off op-com should do it, or if you have a ELM327 adapter, the app "Scan My Opel" for a couple of quid from the Android App store will do it too.

Cheers for that, I think all Vauxhalls from the late 90`s to mid 2000`s had a similar system. 

 

I cleaned up as many related connectors as I could find yesterday, including the coolant ECU ones behind the bumper, not easy thanks to its position & the fact I didnt take enough tools with me, plus the female plug section has loads of tiny pins, so almost impossible to clean.

 

The fan warning did come up on the dash while I had it disconnected (no warnings before), so at least that part of the circuit is functioning.

 

Weirdly, the petrol gauge jumped from almost empty to a quarter of a tank after I did all that.. So was that under-reading before, or is it now over-reading.. I guess we wont know till she runs out of fuel..

 

Also cleaned the fan contacts, removed & refitted the fuses & relays (not easy in the Zafira as the fuse box is literally under the screen & is virtually unreachable.. Terrible positioning).

 

The AC fan still isnt coming on with the AC, both fans come on when engine reaches temp instead.. 

 

After I did all that, I followed her to the supermarket about 5 miles away, waited outside for an hour while she was getting her shopping.. I parked next to it, the fan didnt come on while she was in there. She came out, it started fine.

 

Have I solved it? God knows... I`m waiting to hear from her this morning. If its dead again, I`m gonna go & put another battery on it, & if that doesnt solve it I`m telling her to get rid.

 

Thing is, a tatty 13yo, 140,000 mile, 2.2 auto its worth tupence ha-penny, unsurprisingly she doesnt want to spend money on it, when I was underneath I noticed its got a fairly substantial oil leak & a split inner driveshaft gator that`ll need doing for its next MOT as well.

[SiC]

Iirc the fans doesnt come on our Astra with AC on, until it gets up to temperature. I think that's the coolant ECU job where it knows there is AC demand and will kick the fans in earlier. Unlike older systems where AC switch was hard wired to turn on the fans. If the aircon still works, should be seen as a bonus anyway! Most have killed their thermal fuses in the aircon compressor clutch.

 

2.2l petrol? Isnt that the one with dodgy fuel pumps, timing chains that stretch and a whole manor of foebils? If so, def don't spend any money on it! Tbh, given what they go for second hand (especially a big engine petrol), they're not worth selling. Just run it till it goes pop.

[SiC]

Oh if the fuel gauge is anything like the Astra (it probably is), then don't trust it too much! When you turn off the ignition and back on, it takes a direct measurement and then while the ignition is on it starts averaging it from that point.

 

So if you park on a kerb or similar, the gauge will read very different after turning the ignition off and on. So much so, we've had it where you turn it off without the fuel warning light on. Turn back on and it's flashing the empty light, but carry on driving for a few miles and it then averages back up and slowly goes from OMGempty, to need to refuel, to all is fine...

 

Not a fault with that particular car, just a quirk of Vauxhall of that era. The same with the coolant gauge. As long it's not near the red it's fine. Yet it'll wiggle above half way, rad opens, wiggle below. Looks like a thermostat is sticking and/or getting too hot. It's not, just another quirk. A bit disconcerting, especially when you're used to modern cars getting temp gauges get to half way and stick there all the time.

[Rocket88]

 

 when I was underneath I noticed its got a fairly substantial oil leak & a split inner driveshaft gator that`ll need doing for its next MOT as well.

 The car, or the owner?

[uk_senator]

Iirc the fans doesnt come on our Astra with AC on, until it gets up to temperature. I think that's the coolant ECU job where it knows there is AC demand and will kick the fans in earlier. Unlike older systems where AC switch was hard wired to turn on the fans. If the aircon still works, should be seen as a bonus anyway! Most have killed their thermal fuses in the aircon compressor clutch.

 

2.2l petrol? Isnt that the one with dodgy fuel pumps, timing chains that stretch and a whole manor of foebils? If so, def don't spend any money on it! Tbh, given what they go for second hand (especially a big engine petrol), they're not worth selling. Just run it till it goes pop.

The AC fan doesnt kick in on its own at all, whether the AC is on or off, hot or cold, it just seems to be running in parallel with the rad fan. The AC doesnt work, but it points to a triggering problem to me.. 

 

It actually runs amazingly smoothly for a car thats not been serviced (or even washed) for about 5 years, I`d imagine it`d take a good few more years of abuse to make it go pop, but its other assorted electrical issues & financially non-viable MOT bills are likely to kill it well before then..

 

Oh if the fuel gauge is anything like the Astra (it probably is), then don't trust it too much! When you turn off the ignition and back on, it takes a direct measurement and then while the ignition is on it starts averaging it from that point.

 

So if you park on a kerb or similar, the gauge will read very different after turning the ignition off and on. So much so, we've had it where you turn it off without the fuel warning light on. Turn back on and it's flashing the empty light, but carry on driving for a few miles and it then averages back up and slowly goes from OMGempty, to need to refuel, to all is fine...

 

Not a fault with that particular car, just a quirk of Vauxhall of that era. The same with the coolant gauge. As long it's not near the red it's fine. Yet it'll wiggle above half way, rad opens, wiggle below. Looks like a thermostat is sticking and/or getting too hot. It's not, just another quirk. A bit disconcerting, especially when you're used to modern cars getting temp gauges get to half way and stick there all the time.

It was odd, I was under it with the engine running to get it up to temp, the day before & when I started it, it was on the second red line, when I got out & checked the dash when the fans kicked in, the gauge had gone up to a quarter all on its own, without me moving it at all.

 

 The car, or the owner?

She was wearing a fairly short skirt while I was laying under the car, but yes, I meant the car.. 

[uk_senator]

Just had a call from her..

Last night she got home fine after I left her, that was about 5:30.. Then about 8, she went out & it started fine..

This morning, it started fine.. She`s gone to do more shopping, 20 minutes later, she`s come out of Asda, & yes, not enough power to turn it over.. At that point there were no fans.

She`s then said she`ll ask if anyone can give her a jump start & will call me back in a bit..

2 minutes later, while I`m typing this, she`s called back saying the fans have come on on their own without her touching the key again (remember, this is 30 minutes after it was turned off). 

She`s currently getting a jump start from someone..

[SiC]

Remove the fan controller and then mod the fan (with a relay) so it always comes on at a slow speed (in series) when the ignition is on?

 

I suspect it's the fan controller at fault. I assume it's not chocked full of water? Iirc, they're swappable without needing coding.

 

Really need to get the error codes read tbh.