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1999 S70 Radiator fan not turning on.

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

fresco
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fresco

1999 S70 Radiator fan not turning on.

Post by fresco » Tue Oct 15, 2019 11:39 pm

Replaced:
New thermostat
New ECT sensor

Water temperature gauge needle at 1/2 position (although suppose to be on red - new ECT and thermostat) since coolant is boiling, however fan does not go on. Turning AC on or off does not make any difference.

Unplugging ECT sensor turns the fan on. Plugging ETC sensor back on shuts down the fan.

Grounding yellow and yellow/white wire at the relay switch turns fan and low fan on.



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abscate
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abscate

Re: 1999 S70 Radiator fan not turning on.

Post by abscate » Wed Oct 16, 2019 2:40 am

Did you use a Volvo OEM sensor?

Known to be good: fan wiring, Ecm to fan relay wiring

Need more information on Conditions of coolant boiling over, the dash gauge isn’t a precision instrument. Think of it as a three led lamp; cold, correct, overheat


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A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW
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fresco
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Re: 1999 S70 Radiator fan not turning on.

Post by fresco » Wed Oct 16, 2019 8:50 am

I got the sensor from auto supply store, need to ask them what brand that was.

Not sure how to answer the last question it is boiling over because fan will not go on at all, unless ECT is unplugged.



fresco
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Year and Model: 1999 s70
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fresco

Re: 1999 S70 Radiator fan not turning on.

Post by fresco » Sun Nov 03, 2019 4:02 pm

that was temperature sensor:

I have replaced it 3 times (all aftermarket $18.99, $26.99 and $7.99).
the ironic is that the one that finally worked was purchased on amazon for $7.95...
sold by Dade-US

https://www.amazon.com/gp/product/B01FU ... UTF8&psc=1



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