A/C issues

[Ernie D]

Recently I took my 540 off of the road for a couple of months, and I just put tags back on it a couple of days ago, and noticed I have a couple of gremlins develop in the climate control.
The A/C works, but for some reason now, the heater valve is staying on, so the heater is trying to over power the AC, also the servo motors for the vent heat on driver and passenger side do not work anymore, they are on cool which is a good thing but, you cant switch them to heat if you wanted to, the center vent does change from cool to hot as normal, but as its on cold, the heater still is on trying to over power the cool.
Im suspecting maybe a ground issue may be happening, because my heated seats and reverse lights also became issues of not working.
The only thing Ive done to my car recently was a volvo electric fan mod, but I installed it on a completely seperate harness I made up, and used the volvo relay plus a seperate relay to switch it on via a manual switch that I installed on the center console.
The heated seats issue started before I installed the volvo fan, so I dont think its related, but the seat issue I believe its also a ground problem due to the fact, that besides the heaters not working, the backlighting on the switches for the heaters do not work now when the lights are switched on, on both driver and passenger seats.
The issues I have, as far as I can tell, I suspect a ground lug issue or a ground splice
Could someone chime in and advise if Im in the ballpark with this, one of the electrical gurus could give their opinion also.
Thanks

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[Sleepyhead97]

Heater valves fail open right?

[Ernie D]

Heater valves fail open right?

Yes they do, Ive narrowed it down to a ground issue, the heater valve connector, the terminal for the right side are corroded, Im currently waiting on some new terminal leads to arrive so I can redo the whole connector and go from there

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[ross1]

A bit of crud in the cooling system can also block the valve(s) open.

[Sleepyhead97]

Yes they do, Ive narrowed it down to a ground issue, the heater valve connector, the terminal for the right side are corroded, Im currently waiting on some new terminal leads to arrive so I can redo the whole connector and go from there

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awesome. Hope it works out for ya

[Ernie D]

Well, I repaired a bad pin on the heater valve connector for the passenger side valve, and it still isnt working through the heater control in the car. If I ground it independently, the valve is working, so I eliminated the chance of it not working.

I performed a continuity check between the heater valve plug to the heater control on the dash, the wire tested good, then performed the same test from the heater control on the dash to the IHKR and that wire test good also.
My next guess would be the IHKR not working that heater valve like it should, or could it be a bad temp sensor for the passenger side not completing the circuit?

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