1997 850 Strange One..?

Fogducker · Post by **Fogducker** » 01 Dec 2014, 15:47

Hi folks, I have a strange issue here, 1997 850AWD Turbo 5sp wagon.

Dash "check engine" light came on, scan showed code P0016 for a problem with the ECT coolant temp sending unit, noticed the radiator cooling fan was running after the engine was shut down as well, engine temps were normal.

Reading up on this issue it is common to have the cooling fan run if the sending unit is faulty it appears, I checked the plug connections and wiring for the sending unit and assumed the sending unit is faulty, ordered a new one.

Until the new sender arrives I unplugged the radiator cooling fan so it doesn't run on and drain the battery.

Today I got some information that if my A/C is having issues, which it is due to low refrigerant, ECC lights blinking, this could cause the rad cooling fan to run on as well? It is winter here so I have left the A/C turned off at the ECC unit and planned to recharge in the spring.

With all this info I thought I would check and see if the rad cooling fan would run on with the A/C turned on, plugged back in the rad cooling fan, it did not come on, but the battery totally died, this was almost immediate, I had just driven the car into the driveway...........so........my thoughts are perhaps the radiator cooling fan relay has issues???

Sorry for the ramble but I hope you get the basic idea of the issue, any input appreciated.

Jeremy

Post by **jreed** » 01 Dec 2014, 18:23

One option that might help would be to measure the resistance of the ECT and see if it is reading about right for the temperature.
There was a good post by cn90 here that lists the expected values:
https://www.matthewsvolvosite.com/forums ... hp?t=52203

Fogducker · Post by **Fogducker** » 01 Dec 2014, 18:25

jreed wrote:One option that might help would be to measure the resistance of the ECT and see if it is reading about right for the temperature.
There was a good post by cn90 here that lists the expected values:
https://www.matthewsvolvosite.com/forums ... hp?t=52203

Thanks, good idea, at least it would rule out the ECT...

Post by **jreed** » 01 Dec 2014, 19:24

Thanks! Let us know what you get for resistance.

tzanis · Post by **tzanis** » 02 Dec 2014, 19:19

The same thing was happening to me when I firstly bought my car. Maybe my suggestion does not fit your problem or error code, but check if your thermostat is broken and also the temp sensor is giving the correct reading. After replacing those my car was fine. hope it helps

Fogducker · Post by **Fogducker** » 03 Dec 2014, 07:26

New thermostat and temp sending unit have been ordered.....