The great radiator fan mystery...

[TuscanHunty]

Hi all,

I'm after a bit of advice although I'm pretty sure it's now beyond my ability and needs to go to the specialists!

I have a 2000 Tuscan with neither cooling fan working.

So here are the facts..

Neither cooling fan comes on at all no matter what the temp so traffic is very dangerous and things need to be sorted quick!
I've checked the fuses, they're ok.
I've checked the spade connectors next to the fans, these have been cleaned and reconnected.
I've run the diagnostics software, when the engine gets to temperature, the laptop says both fans are on. But they arent!

And..

I get an EFI fault quite often on the pod.
I get interference on the radio at anything over 1500 revs suggesting an earth problem?
Could this all be linked??


So the question is. What should I try next?! Or.. Should I admit defeat?? (my inner man pride depends on it)

Thanks in advance.

Jon

[Targarama]

Fan Relay?

[nrick]

Fan relay +1

Have you tried putting power directly to the fans to see if they run, be unusual for both to be down. On mine the cable wasn't fastened down and the cable got chewed a little, but again unusual for both. I would still say the fuse board/fuses/connectors

So in no particular order (Except cost)

I) change the fuses/relays again
ii) check the connectors
iii) check to see if there is a voltage at the connector when the ecu says there should be
iv) put power on the fans to see if they run (BTW you could manually run the fans this way on a relay and switch)
v) Check the cables for fraying/earth faults

Hope that helps

Neill

[nrick]

oh one other thing, if the temp sender is unplugged the ecu gets a signal to fire the fans to protect the engine, so I would do that first.

[TuscanHunty]

Thanks for the advice guys, time to buy a multimeter and check power out of the fuse board then. Could be the relays. Tried swapping them and cleaning connections but of course if they're both out it wouldn't make any difference. I don't think it's a temp sensor problem as the pod and the diagnostics software gives good readings, I.e. Not 95 deg constant as I understand it would with a faulty sensor.

Watch this space.. Any more ideas are welcome!

[TuscanHunty]

Thanks for the advice guys, time to buy a multimeter and check power out of the fuse board then. Could be the relays. Tried swapping them and cleaning connections but of course if they're both out it wouldn't make any difference. I don't think it's a temp sensor problem as the pod and the diagnostics software gives good readings, I.e. Not 95 deg constant as I understand it would with a faulty sensor.

Watch this space.. Any more ideas are welcome!

[TuscanHunty]

How would you hard wire the fans to check them? Directly onto a slave battery with a switch??

Thanks. Really appreciate the help!

[ninetynine]

carefully remove the yellow covers on the relays and you can push the contacts to make fans come on
this will prove fans and fuse ok and weather problem is relay or sensors can also be poor connection to ecu

[dvs_dave]

TuscanHunty said:

Thanks for the advice guys, time to buy a multimeter and check power out of the fuse board then. Could be the relays. Tried swapping them and cleaning connections but of course if they're both out it wouldn't make any difference. I don't think it's a temp sensor problem as the pod and the diagnostics software gives good readings, I.e. Not 95 deg constant as I understand it would with a faulty sensor.

Watch this space.. Any more ideas are welcome!

FYI, the ECU uses a separate temp sensor from the POD (it's below the airbox), so temp display on the pod is no indication that the ECU temp sensor is working ok.

[TuscanHunty]

Thanks Dave, good knowledge! thought that might be the case. Diagnostics software shows similar (but not the same) temp readings as the pod so I'm guessing the temp sensor isn't an issue? Unless theres yet another sensor!

[WhyTwo]

If you disconnect the sensor under the airbox do the fans come on? I had a problem (documented on here back in June/July 2009) which meant running the fans permanently all the way back from Le Mans, this is how I did it.

If your's don't come on after this then you can eliminate the sensor as the issue

Edited by WhyTwo on Friday 15th April 13:18

[Basil Brush]

dvs_dave said:

TuscanHunty said:

Thanks for the advice guys, time to buy a multimeter and check power out of the fuse board then. Could be the relays. Tried swapping them and cleaning connections but of course if they're both out it wouldn't make any difference. I don't think it's a temp sensor problem as the pod and the diagnostics software gives good readings, I.e. Not 95 deg constant as I understand it would with a faulty sensor.

Watch this space.. Any more ideas are welcome!

FYI, the ECU uses a separate temp sensor from the POD (it's below the airbox), so temp display on the pod is no indication that the ECU temp sensor is working ok.

The diagnostic software shows the reading from the ecu sensor though so, as OP said they give similar values, it looks as though both sensors are ok.

[nrick]

I was only suggesting that disconnecting the sensor should cause the fan to come on as the ecu defaults to a safe setting if out of range.

[drivingfroggy]

When mine played up, it was corrosion on the spades of the sensor under the airbox, a quick clean up with emery paper and it all worked.

[TuscanHunty]

Well the mystery has been solved tonight! After checking the relays by prising off the covers and holding the connections together with elastic bands I took the multimeter to see what voltage if any was at the spade connectors. As soon as I moved the connectors, the fans spun to life and I damn near s41t myself. So the problem was the spade connectors. not the actual connections themselves but the wires crimped into each side had corroded. So it was the first thing i looked at and after a few hours poking around was also the last!

Does anyone know if there's a better replacement? Perhaps something a little more weather proof?!

Thanks again all, there's no way I could have done this alone!

[nrick]

Glad you got it sorted. There are other connectors around, I used to work for a waterproof connector company, you pays your money and takes your choice. I might do it as well, RS is your friend (or Maplin).

[nrick]

http://uk.rs-online.com/web/search/searchBrowseAct...

Might be a bit bulky, but IP67 sealed.

[nrick]

or these

http://uk.rs-online.com/web/search/searchBrowseAct...

[dvs_dave]

Each fan circuit is rated at 30A and those two connectors above are only rated at 8A and 10A respectively!! Each fan pulls about 20A (more on startup) when running so will melt (or worse!) those connectors in no time.
Click here to see Tuscan radiator fan data sheet

I replaced my connectors with the same as the originals which have the correct current rating. I got them from here, and they are the "MC2" connectors which are the two terminal versions:

www.vehicle-wiring-products.eu

Unfortunately I couldn't find any weatherproof connectors that could safely handle the amperage, and I guess TVR probably had the same problem? What I did to weather-proof them was to liberally spray the connectors in lithium grease, finished off by a generous dousing in silicon spray. Whenever I take the bonnet off, I also give the connectors a quick squirt with silicon spray (along with all other electrical connectors) to keep things nice, dry and corrosion free.

[nrick]

Hi

Just giving the general idea, the bulgin 900 range will handle upto 32a. We had the ones up there on the test bench at higher amperage than 12a but safety first. 20a at running is very high the cable doesn't look like it would take 30a?