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[LC0112G]

Is there an easy way to test the main radiator fan is working?

I mean the big one inside the engine bay at the back of the rad, not the two infront of the rads. Got stuck in some traffic today and the temp guage shot way up over 100, and the red warning lamp came on. Turned the blowers up to full and "HI" and it came back down pretty sharpish, but never heard the fan come on. So one of tomorrows jobs is to make sure it works. Haynes circuit diagrams suggests there is a test socket in the engine bay fuse box. Anyone know how to use that? Or is it just a case of pulling the relay and shorting the pins?

Cheers
Malcolm

[05omegav6]

Unplugging the relay and shorting pins can work, but it can also release magic smoke

Unplug the fan and run two wires up to the battery

If the fan spins then you can rule it out, next likely culprit is the thermoswitch on the radiator

Obviously watch your fingers/hair/clothes/tie/assistant whilst doing this

[Andy B]

Is there an easy way to test the main radiator fan is working?

I mean the big one inside the engine bay at the back of the rad, not the two infront of the rads. Got stuck in some traffic today and the temp guage shot way up over 100, and the red warning lamp came on. Turned the blowers up to full and "HI" and it came back down pretty sharpish, but never heard the fan come on. So one of tomorrows jobs is to make sure it works. Haynes circuit diagrams suggests there is a test socket in the engine bay fuse box. Anyone know how to use that? Or is it just a case of pulling the relay and shorting the pins?

Cheers
Malcolm

The test point is the pink socket in the traingular fuse/relay box under the bonnet.

http://www.autobahnstormers.org.uk/forum/viewtopic.php?f=18&t=15375   

[LC0112G]

Is there an easy way to test the main radiator fan is working?

I mean the big one inside the engine bay at the back of the rad, not the two infront of the rads. Got stuck in some traffic today and the temp guage shot way up over 100, and the red warning lamp came on. Turned the blowers up to full and "HI" and it came back down pretty sharpish, but never heard the fan come on. So one of tomorrows jobs is to make sure it works. Haynes circuit diagrams suggests there is a test socket in the engine bay fuse box. Anyone know how to use that? Or is it just a case of pulling the relay and shorting the pins?

Cheers
Malcolm

The test point is the pink socket in the traingular fuse/relay box under the bonnet.

http://www.autobahnstormers.org.uk/forum/viewtopic.php?f=18&t=15375   

Thanks - that's exactly what I was looking for but couldn't remember where I'd seen it !

[LC0112G]

Ok, tests confirm summut's up. Short question - where is connector X5 (Haynes page 12.47 line 730 ish)

Long explanation..

The car is a Y reg facelift X30XE Elite with Aircon. The underbonnet relay layout is the same as the second layout in Mark DTM's thread here : http://www.omegaowners.com/forum/index.php?topic=90458.msg1155241#msg1155241

Namely this :


The fan test connector is the purple connector above relay position 17.

Shorting the Fan test connector pin FT1 (Haynes XP1 Pg 12.47 line 753) causes all fans to run slow. Correct
Shorting the Fan test connector pin FT2 (Haynes XP2 Pg 12.47 line 764) causes all fans to run slow. Correct
Shorting the Fan test connector pin FT4 (Haynes XP4 Pg 12.47 line 770) nothing happens. Duff
Shorting the Fan test connector pin FT5 (Haynes XP1 Pg 12.47 line 754) nothing happens. Duff

So I pulled Relay K67 (dark blue) and shorted the contact terminals in the connector (pins 4/30-8/87) - The main fan ran full speed (and my shorting link emmitted a proportion of it's latent smoke - note to self use thicker wire  )

Next I con-checked between Fan test connector pin FT4 (Haynes XP4 Pg 12.47 line 770) and Relay K64 coil contact 6/85. Con-checked Ok.

Next measure the voltage on Relay K64 coil contact 2/86. Should be +12V, but nothing.

According to Haynes, the same line also goes to Relays K28, K48 and K52. So pulled K52 (brown) and checked pin 4/86. No +12V there either.

It looks like the +12V feed to the coil of both relays is missing. Haynes suggests that this wire comes from Fuse F15 via connector X5.  I've checked Fuse F15 in the drivers footwell, and it's 20A and intact. So assuming that's the correct F15, and that Haynes is correct for facelifts, where is connector X5?

Cheers
Malcolm

[05omegav6]

According to Vauxhall, it's next to the battery so likely one of the 2/3 round plugs...

[LC0112G]

Ahhh - may be Fuse F29 : http://www.omegaowners.com/forum/index.php?topic=64914.msg925297#msg925297

[LC0112G]

Ahhh - may be Fuse F29 : http://www.omegaowners.com/forum/index.php?topic=64914.msg925297#msg925297

Or not. F29 is something to do with the tow bar lectricery. Plus the FT1 and FT2 wouldn't work if those circuits were also powered off F15/29.

[LC0112G]

Spent lunchtime drawing out the circuit diagram of the fan stuff into a more understandable format. Then the penny dropped. F15 isn't live unless the ignition switch is on, which means the description on the ABS site pdf is wrong - at least for my car. The circuit in Haynes appears to be correct - for a Face lift X30XE anyway. So..

Ignition Off
Fan test connector pin FT3 = Low/No connection
Fan test connector pin FT6 = Ground/Chassis/OV
Shorting the Fan test connector pin FT1 (Haynes XP1 Pg 12.47 line 753) causes all fans to run slow.
Shorting the Fan test connector pin FT2 (Haynes XP2 Pg 12.47 line 764) causes all fans to run slow.
Shorting the Fan test connector pin FT4 (Haynes XP4 Pg 12.47 line 770) nothing happens.
Shorting the Fan test connector pin FT5 (Haynes XP1 Pg 12.47 line 754) nothing happens.

Ignition On
Fan test connector pin FT3 = +12V (F15)
Fan test connector pin FT6 = Ground/Chassis/OV
Shorting the Fan test connector pin FT1 (Haynes XP1 Pg 12.47 line 753) NSF+OSF fans fast. Main Fan Slow
Shorting the Fan test connector pin FT2 (Haynes XP2 Pg 12.47 line 764) causes all fans to run Fast.
Shorting the Fan test connector pin FT4 (Haynes XP4 Pg 12.47 line 770) Main Fain Fast - other fans off.
Shorting the Fan test connector pin FT5 (Haynes XP1 Pg 12.47 line 754) OSF Fan On - other fans off

I think thats correct. Anyway, I believe my car behaves as the Haynes wiring suggests it should, so that means that all the relays, fans and fuses are Ok. Therefore, if there is a fault it's gotta be the radiator temperature sensor. 

[plym ian]

Would a faulty thermostat not cause similar problems?

[LC0112G]

Would a faulty thermostat not cause similar problems?

Yes, but I put in a brand new thermostat whilst swapping engines. Doesn't mean the new thermostat isn't faulty of course but easier to change the rad switch first before attempting to remove the thermostat and throwing it back at Vx.

[LC0112G]

Definatley something wrong. Just done a 4 hour round trip to get the B52's in Fairford, and the USAF C-130's in Brize, and I've had to have the heater on and windows down most of the way there and back. Worst seems to be when you're stuck behind some dithering old biddy doing 30MPH in an NSL, when the temp rises to between 95 and 100. Best seems to be steady cruising at 50MPH when the temp sits just below 90. My (admittedly alcohol addled) brain seems to remember the temp sitting at a rock steady 85 before the engine change.

Both top hoses are rock hard and red hot, but no fans running. Beginning to think blocked rad, or failed water pump - or worse.

I've got both new thermostats now, so tomorrow is rad out, flush, and fit the new stats.  Might stick a temp probe in the fins of the rad before and after to gather some info

Any one got any other bright ideas?

[Kevin Wood]

Sounds like it's just a failed fan to me. You wouldn't have got that far with a failed water pump.

I don't suppose there's been oil in the system? Thinking the face of the fan switch might be contaminated, preventing it from seeing the true coolant temperature.

[Bigron]

If the hoses are THAT pressured, could it be head gasket?

Ron.

[LC0112G]

If the hoses are THAT pressured, could it be head gasket?

Ron.

Thats what I meant by "or worse". Sniffy doo-daah test passed ok though.