Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regagain!

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ecohouse1
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Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regagain!

Post by ecohouse1 »

Hi
I posted back in November about my Rad fans coming on when the car was cold, and got great advice that the wiring connector on the brown sensor on the thermostat housing was the likely culprit, as the bad contact there raises the resistance which then sends a signal to the bitron that the engine is hot & runs the fan. Anyways, wiggled the connector, and removed and refitted in November and bingo - fans stopped running when cold and normal operation was restored.

Its just started again so immediately assumed that it was due to the same thing. Removed connector, gave everything a clean- it all looked clean & shiny anyway- and the fans are still running when cold.

What happens is - cold start - even when glow plug lights are on, one fan starts slow speed then second or two later - both fans on full blast. Start engine, fans still run a while then shut off after variable time periods. Always off when in normal operating temp range- come on when too hot.

When the fans are running on cold engine - and I take off the brown sensor pug they keep running. I then push the plug back on - they stop - then come back on - accompanied by a click which seems to be coming from the dark recess of the LH side of the engine behind the fusebox/LHM area?

I have ordered a sensor from fleabay, although I don't think its really the issue but maybe the contacts will be better - it was only £14. On the existing sensor, Resistance was 1440 ohm on cold - when testing on a warm engine (90 mins after a fast run) it was around 2500 ohms - so seems to be reading within parameters.

Before I start yanking the front bumper off to access the bitron as I am assuming its a dirty contact somewhere in one of the wiring plugs that's the issue, is there anything else I could try that has easier access. It happened after driving on a wet sleety night then parking up a few days. On starting the fans started again and now its pretty much every cold start.

Any advice greatly received.
Cheers
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Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by Stickyfinger »

It could also be a fault in the wire loom.....they get rotten down there because the loom is poorly protected and quite exposed.

IF you do have to go in, the bumper is not a bad job to remove, after fixing the problem/wires, CHECK and clean out the lower parts of you rad before you replace the plastic....you will more than likely find lots of crud in there.
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Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by MikeT »

I would still suspect the connector is making poor contact which improves when metals expand due to heat of engine or when you assert reconnection by fiddling with it.

I base this on the fact that without any sensor input or a wiring fault (ie, remove the plug) it goes into "failsafe mode" which sensibly puts the fans on at high speed just in case.
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Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by Stewart(oily) »

Is your aircon switched on ?
Is one of the relays on the front of the radiator stack stuck ?
Stewart
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
ecohouse1
Posts: 283
Joined: 29 Aug 2011, 12:44
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Deceased
Xantia TD Estate 1999 (now with Chris Morewood)
Xsara 1.9D Saloon
BXTZD Break
BXTGD Hatch
Peugeot 309 1.9D
Various 2CVs
Porsche 924 lux
Porsche 924S
Renault Clio 1.4 Auto
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Triumph Herald 1200
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Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by ecohouse1 »

Air con definitely off. Will check the other wiring connectors including the thermistor one. Have ordered electrical contact cleaner. Hopefully that will help. Many thanks
ecohouse1
Posts: 283
Joined: 29 Aug 2011, 12:44
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My Cars: Rover 75 CDT TourerAuto , , Mercedes 190E 1.8 1993, 2CV6 Special 1987, Peugeot 206 1.1 2001. Repairs and maintenance of two Hyundai i10s
Deceased
Xantia TD Estate 1999 (now with Chris Morewood)
Xsara 1.9D Saloon
BXTZD Break
BXTGD Hatch
Peugeot 309 1.9D
Various 2CVs
Porsche 924 lux
Porsche 924S
Renault Clio 1.4 Auto
GSA Pallas
Triumph Herald 1200
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More Bitron/Rad Fan issues!TD T regagain!

Post by ecohouse1 »

Update on my Rad fans. New thermistor arrived - installed it and absolutely no difference so put the old one back on! Also used contact cleaner on the connection. Next morning fans stayed off - great. But after work (after car sitting 9 hours) on again!

Just thinking I had the N/S wing off to weld the lower front door hinge. I didn't disconnect the battery. Is there any chance that you can "spike" and upset the bitron unit by doing this? Has anyone experienced this after welding. Admittedly it didnt happen immediately after welding. Also is there anything in the area under the wing that I could have disturbed that impacts the bitron?

On another note, just out of interest, I notice a free connector in the area under the wing that is not connected to anything behind the indicator ( but not the indicator connection!) I notice also that there is a 3 prong male connector on the n/s upper part of the radiator. Its all corroded so had never been connected to anything. What is that for?

Many thanks
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Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by Xantidote »

ecohouse1 wrote:a free connector in the area under the wing that is not connected to anything behind the indicator

this might be for front fog lamp (unless you already have them :) )
Martin

1995 Xantia TDLX (deceased :( )
ecohouse1
Posts: 283
Joined: 29 Aug 2011, 12:44
Location: Aberdeen
My Cars: Rover 75 CDT TourerAuto , , Mercedes 190E 1.8 1993, 2CV6 Special 1987, Peugeot 206 1.1 2001. Repairs and maintenance of two Hyundai i10s
Deceased
Xantia TD Estate 1999 (now with Chris Morewood)
Xsara 1.9D Saloon
BXTZD Break
BXTGD Hatch
Peugeot 309 1.9D
Various 2CVs
Porsche 924 lux
Porsche 924S
Renault Clio 1.4 Auto
GSA Pallas
Triumph Herald 1200
x 3

Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by ecohouse1 »

OK - removed N/S headlight, drilled a couple of holes in the bumper support panels to get access to the Bitron mount bolts. Wiggled the Bitron out and removed sliding catch and plug. Cleaned it all up with electrical contact cleaner and reassembled.Was supprised how much dried mud etc was on it. Fitted rubber gromits into the holes. Now the fans don't come on when cold, but do randomly come on when warm (ie run then off an hour or so) less fan action than before but not back to normal. Will see how things go for the next week or two. Not sure if I have a dodgy contact somewhere or the Bitron is playing up? Not really sure where to go from here. All the relays seem to be working normally :?
ecohouse1
Posts: 283
Joined: 29 Aug 2011, 12:44
Location: Aberdeen
My Cars: Rover 75 CDT TourerAuto , , Mercedes 190E 1.8 1993, 2CV6 Special 1987, Peugeot 206 1.1 2001. Repairs and maintenance of two Hyundai i10s
Deceased
Xantia TD Estate 1999 (now with Chris Morewood)
Xsara 1.9D Saloon
BXTZD Break
BXTGD Hatch
Peugeot 309 1.9D
Various 2CVs
Porsche 924 lux
Porsche 924S
Renault Clio 1.4 Auto
GSA Pallas
Triumph Herald 1200
x 3

Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by ecohouse1 »

Had a really good look at this at the weekend and stripped off the n/s wing as I had been working on the front door hinges in the vicinity back in April and shortly after the wierd fan operation started again. Any way all looks fine. No wire damage etc evident. Have noticed that if I pull out the changover 5 pin relay the fans go off as expected but do not come back on again for a while. The problem sort of goes away for a few starts, then comes back and am beginning to wonder if it could be an internal fault on one or other or the fan relays. There is no sign of overheating, but it mostly comes on in cold start scenarios then stops after as little as 10 seconds or run for many minutes while driving. Fiddling with the relays in the fan area seems to change the symptoms, so ordered a 5 pin relay to try that out (I tried to open the old one but no luck it seems solidly build!) Hot fans run as normal. Although the 206 1.9D Bitron made the engine run hotter at standstill (up o almost 100) which I didn't like. Switched back to my original bitron unit & fans cutting in at 90 on my temp guage.

Driving me mad. Good old French electrics. You got to love them.
Stewart(oily)
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Joined: 07 Oct 2005, 16:31
Location: North Wales
My Cars: Citroens since 1990, BX Diesel, GTI, TZD with 1.9 TD running extra boost before it was fashionable!, ZX Volcane TD, S2 Xantia break 1.9TD, Xantia HDI 110, currently zipping about in a C2 Diesel. C2 died from the dreaded worm, C3 Picasso HDI Exclusive, the adventure continues.
x 31

Re: Help! Bitron/Radiator Fan issue on Xantia 1.9TD T regaga

Post by Stewart(oily) »

I think the fans on Xantias do switch at 95 degrees, whilst older models did so at a lower temperature, I managed for a good few years with the bitron unit sitting loose behind the headlamp (I left the original one where it was and connected the new one)
BXs since 1993 built 1.9 TZD turbo, got a S2 Xantia estate, brilliant car! 2013, Xantia HDI LX 110 2000 new car with 122,000, l C2 HDI Rusty rocket, C3 Picasso HDI new to me.
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