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Po840 code is shown both fans are working and relays are working

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The description I get for code 840 is a problem with the transmission pressure sensor.
You might want to check with GM on that.

Posted on Jan 10, 2013


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Cooling fans not coming on in 2007 chevy equinox

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I have only looked at a couple of schematics (circuit drawings) but each one has shown a relay (actually 2) being operated by the temperature sensor(s)...

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or not... but you always wanted a spare to carry with you... Yes?

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Dodge Stratus R/T fan doesn't come on while car is running and car is getting hot.


It can be issue with faulty motor or its faulty fan control relay.

Bother are to be inspected.

Test volt at fan relay and fan motor.


For more help, I suggest you to go through the troubleshooting links mentioned below:-----

Click the link below: ------

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My car turns off after i turn it on ,or when stoping ,chrysler lhs 99

the code 1490 is for the low speed fan. does it over heat. the other code is for battery being disconnected. has the battery be disconnected if it has not check the battery post to see if they are tight

Nov 26, 2012 | 1999 Chrysler LHS

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The code reader says i need a fan relay but when i checked under the hood it was a big 30A fuse,i changed it but the fan still doesnt turn on, also i took out one of the fans before i used the code reader,...

you do need both fans in order for the system to work the other fan relay is on the firewall behind the glovebox check that but usually the computer says its a relay but in all reality its usually the fans I would certainly check the relay but would also try running a jumper wire from the battery to the positive wire to the fans if they power up its not the relay but the switch

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1996 corrvette cooling fans do not come on unless u put on ac. Scanner reads same temp as analog reads[ 0 ] Car will overheat other wise. thank you

sounds like the cooling fan isn`t coming on when its suppose to.if you have 2 fans on the car then the one that comes with the a/c only works with the a/c.the other one works with the engine temperature sensor that sends a signal to the computer that turns on the cooling fan.cooling fans are a common problem with gm`s.with jumper wires you can feed the fan directly from the battery if it won`t work then the fan needs could also be the fan relay in the relay box.have you checked the fuses.with it having been on a scanner it should have shown a code for the circuit,as such if there was a problem with the relay,fuse or computer it should have shown i would say its probably the cooling fan motor.

May 09, 2011 | 1996 Chevrolet Corvette

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