Hi guys got a mk4.5 titanium x sport mondeo got a problem with the A\C not working. The clutch isn't engaging I've checked the fuse and relay no issues with either one except the power supply to the relay is 8.45 volts when off and only 10.5volts when it's turned on. I have manually engaged the clutch by making a wiring loom from the relay to an external power supply. Does anyone know if either the power distribution/ fuse box or the heater control panel gives trouble. Everything else is working as it should 

You need to get the gas checked first to eliminate that cause for air con clutch not engaging. While you arrange that check the evaporator temp sensor incase it's got unplugged through pollen filter fitment. Also common is the wiring from pcm to the cooling fan breaks in the harness where it routes on top of gearbox. 

What pins are you checking voltages at ?

The R3 relay under the bonnet, the power side of the relay. Got the gas checked that was OK that when I found out the clutch wasn't engaging I'll check the temp sensor tomorrow. Which fan dose the wire break effect

You should be getting battery voltage at the relay. Check the fuses that supply's the relay and see what voltage you get there. Fuse 13 and fuse 7. 

Hi lads after a couple of hours of tinkering and going through all the suggestions. I switched the relay from the horn to the a/c clutch. Clutch is engaging and the horn is working I'm thinking maybe a weak coil in the relay if the horn stops working that will be the cause but until then I'll be enjoying cold air🥶🥶

Just want to say thanks to iantt for all the support I really appreciate it

Hi guys just a quick question on A/C after getting it going a few days later I started hearing a hissing noise in the car when A/c is on gas levels have remained the same just wondering if the expansion valve give trouble in the mondeos

I've never changed one. But the last 5 yrs or so I haven't done much work on older stuff.