Radiator fan diagnosis

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D.Slatford
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Radiator fan diagnosis

Post by D.Slatford »

Yet another problem with this bloody Xantia (1.9TD 1997). It recently came to my attention that the two radiator fans don't work. I've checked the fuses in the engine fusebox but all seems well. Any hints on where else I can direct my fault-finding?
PeterMann
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Post by PeterMann »

I was having doubts about the fans on my BX. I just ran the engine with the car stationary, and kept an eye on the temp gauge. After about 10 minutes the fans came on ... hadn't noticed them because they run so quiet.
tomsheppard
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Post by tomsheppard »

Xantiae don't work in the same way as BXs though.
Search this forum using Keyword bitron. That may help.
James.UK
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Post by James.UK »

Try bypassing the heat sensor in the radiator and see it the fans kick in. (this works on my car) I'm not sure what the voltage is but maybe you can run a wire directly (thus bypassing everything) to the fan motor to test it? If the fans work by doing that, then you will have to work back, bypassing each item involved untill you find the one thats failed..
Sorry I cant be more explicit but I know virtually nothing about electricity... [:I] [:o)]
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Post by oscarloco »

Try letting your car heat up. At around 90-97 Celsius both fans should come in at low speed. And around 100 - 107 Celsius they should run at full speed. If one is dead, they won't come on at low speed and only the healthy one should turn at high speed when temperature gets high enough.
D.Slatford
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Post by D.Slatford »

Trust me.. neither works at any temperature. I recently did Hardknot Pass in the Lake District, and it was the first time the Stop light came on from over-heating (and stop I did!)
alan s
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Post by alan s »

I see from another posting of yours that I've just answered that your car has air/con in which case the fans will have possibly done a lot more work than non air/con cars, as a result these fans do get a substantial amount of work.
Follow the clues already given but if it turns out that the problem is within the fan itself, then take a peek at this as it could save you some serious cash as I understand these fans are a bit pricey.
http://www.andyspares.com/discussionfor ... C_ID=10752
incidentally, I won't be volunteering to come over to remove and replace for you....sheesh; what a job that is.[:(!][:(!]
Alan S
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Post by RichardW »

Dan,
With aircon, both fans should start when you switch the air con on. If not, the STOP light and over temp lights will flash as the Bitron unit detects a fault. There are 2 (or maybe 3!) temp sensors in the thermostat housing: (IIRC) brown feeds the bitron, green feeds the gauge and blue (If fitted) feeds the ECU. Unplug the brown sensor and both fans should go flat out. I suspect that if you are not getting the warning about the fans not running, then the sensor will be at fault, and the bitron is not recognising the engine getting hot. Although, having though about it a bit more, why did the light come on, as this is controlled by the Bitron, so it must be seeing the high temp?? What temp did the gauge read when the light came on?
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Post by ActivaV6uk »

Hi richard, the info i gave you email me through work if you havent got it wokring all the AC info is in there i think it will give you some interesting reading (and you'll wonder why some things are dont the way they car).
Dan did you find Fuse F3 in the bay? as you rightly point out if that dosent work your fans will be dead.
Andy
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Post by RichardW »

Andy,
Wrong Richard? My aircon is working OK at the moment (ha famous last words!).
However if you've got some air-con info I'd be interested to read it: richard.west at jacobs.com
ActivaV6uk
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Activa, silver MK1 (221bhp stock) stripped out with twin sparcos Evo seats. 95
Activa, light met red MK1 98
Activa, dark met red MK1 98
Activa, dark met blue MK1 (202bhp stock) 96
Xantia exclusive V6 auto 3l 98
Xantia 2l 8v auto
BX 4x4 GTi dark met silver
BX 4x4 GTi white
BX GTi 16v white fibre bumpers
BX GTi 16v black fibre bumpers
BX GTi 16v hurricane (doa)
BX DTR estate

Post by ActivaV6uk »

you have mail :) both Dan and Richard
D.Slatford
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Post by D.Slatford »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by RichardW</i>

Although, having though about it a bit more, why did the light come on, as this is controlled by the Bitron, so it must be seeing the high temp?? What temp did the gauge read when the light came on?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Well, I pulled the brown plug - and nothing happened. No fans, no lights. I'm building up a picture here. A fuse had been missing when I bought the car, this was the first relay coil fuse. The clips missing off the bitron sensor plug too - clearly someone has been here before me and given up.
The temp gauge works ok. It's about 80 on average. Naturally it creeps up when driving slow / standstill. It's something around high 90s when the orange lamp comes on (then it's heater on, fan full, windows down!) The Stop light has come on once when the temp got really high. No fans ever.
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Post by tomsheppard »

Ok, just a flier, 'cos I haven't thought this through fully yet. Is there somewhere on the Xantia rad where a conventional fan switch could be mounted? Were such a thing to exist, copying the BX wiring would avoid the need for the Bitron box. People give up when they find out what a bitron box costs. If your Xantia was cheap, then it wouldn't be too much to pay to get it right.
Early Datsun Cherries had the fan switch in a separate housing in the two piece bottom hose.
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Post by alan s »

As I said previously; are you sure the fans themselves haven't failed, because they have both failed on my air/con equipped Xantia.
If the fans are stuffed, all the bitron boxes and fuese in the World won't make them spin.
Alan S
D.Slatford
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Post by D.Slatford »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tomsheppard</i>

Ok, just a flier, 'cos I haven't thought this through fully yet. Is there somewhere on the Xantia rad where a conventional fan switch could be mounted? Were such a thing to exist, copying the BX wiring would avoid the need for the Bitron box. People give up when they find out what a bitron box costs. If your Xantia was cheap, then it wouldn't be too much to pay to get it right.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I'm getting tired of little things costing prohibitive amounts :(
There's no rad switch on bitron models. The aircon system completely changes how it works - and at some time or other I do want working aircon.
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