98 V70XC - A/C blowing hot air, P0116 code

mindshadow · Post by **mindshadow** » 11 Aug 2014, 12:46

Hey guys. A while back I replaced the coolant sensor thingy (and the thermostat) and had some issues with the wires, so I ended up soldering them back together higher up the wire (they were old and corroded together). I've been throwing a P0116 code with the coolant light on for a while now. My temp gauge stays right where it should at nearly horizontal. The problem is that my A/C isn't coming on, and I'm wondering if it's related. I've looked at the compressor and poked the clutch with a broomstick to see if it would engage, but it's a no-go. If the P0116 code isn't related, what could I look at to get it working? The compressor was working fine (with the breadclip mod) previously. It's hot as balls out and I'd really love some cold air.

Thanks!

Post by **jblackburn** » 11 Aug 2014, 13:52

I can't remember if it was 1998 or just 1999+ models, but the A/C is disabled and cooling fan put into a fail-safe mode if the car can't properly read the coolant temp sensor. By that logic, that P0116 code for the coolant temp sensor circuit would keep the ECU from allowing the A/C clutch to be energized.

mindshadow · Post by **mindshadow** » 11 Aug 2014, 14:00

Word. I'll pull the wiring back apart and see what happens.

mindshadow · Post by **mindshadow** » 15 Aug 2014, 08:23

So, I think it might be the A/C cooling fan relay. I re-wired the ECT sensor, and it was still a no-go. I whacked the cooling fan relay with my multitool and it turned on, and then the fan would not turn off when I turned the car off so I had to unplug the battery. After that the fan would either stay on the entire time, only to be turned off by disconnecting the battery, or it would turn on for a moment when I whacked it.

Does that sound like a bad relay, and if so, could that be the root of my problem?

Post by **Ozark Lee** » 15 Aug 2014, 08:49

That is exactly how the bad cooling fan relays I have had behaved.

...Lee

mindshadow · Post by **mindshadow** » 15 Aug 2014, 12:10

Ok, well, it's on order from IPD. May Mercury (AKA USPS) deliver it swiftly.

mindshadow · Post by **mindshadow** » 18 Aug 2014, 13:49

That didn't fix it.

Coolant light is still on and no A/C. No codes yet, but I just reconnected the battery a few ago. Any other ideas?

Post by **jblackburn** » 18 Aug 2014, 13:53

Could a coolant level sensor or stuck float (reason coolant light is on) disable the AC as well?

Post by **Ozark Lee** » 18 Aug 2014, 13:59

How are the wires to the relay sockets? I have had some trouble with the connectors to electrical items on the fan shroud but, for some reason, the master fuel system relay wiring and connectors have the problems more often than the cooling fan relay. Try using a piece of wire to individually bring the relay pins associated with yellow and yellow/white wires on the center connector to chassis ground. One should trigger the fan at high speed and the other should trigger the fan at low speed. If that works it shows that the relay and the wiring to the fan is OK. The yellow and yellow and white wires come directly from the ECU.

...Lee

mindshadow · Post by **mindshadow** » 18 Aug 2014, 14:05

So pull the middle harness from the relay, connect some wire to each pin, and then touch it to the wire to the exposed pins in the middle of the relay?