2008 VNL780 adding manual fan switch

Also I was thinking to upgrade to a air operated fan clutch.
IS A GOOD THINK TO DO???
Thanks

 

Air operated in my opinion much better and easier to fix, make sure you check your control in the cab as that will cause a lot of problems to, volvo can hook up with scanner and be able to tell if you have ac requesting fan or not, not very likely broken wire if that was the case fan would stay on all the time

 

Thanks Nasriza and KB3MMX, for the quick replay.
I toke the truck to Volvo already and they told me the fan is engaging at what ever % required at the time. But they didn’t do what I ask for .
To see is was commander by the a/c module .
Is anything I can do at pressure switch to activate the fan ( I’m afraid to mess my VCM). Just to make wiring is ok? Before I retrofit it to air.
I appreciate you guys help.

 

nothing you can do since ac timer is programmed in the ecm if you put air need to reprogram and change all parameters, just need to see if module is asking for fan could do with scan tool very simple to do.

 

Thanks Nariza. Do you any reputable shop or somebody who work good in electronics.
If is possible in Jacksonville FL area.

 

i do not i'm out of chicago

 

Thanks for your time and help.
Keep you posted when I able to hook it up to a scanner.

 

Wire from the switch is connected to the AC module. The switch is binary type. If wire is broke it will not work at all. AC module does send request to the VECU to fan ON. You can check is AC module does it if you know how to use digital multi meter. If AC module initiate signal FAN ON check wire to VECU. If not check is AC charged properly freon to tripp switch from low to high.
Circuit diagram is in attachment.

 

Thank you Snailexpress, My a/c is fully charge to specs by a recovery unit. A/C blow cold while I’m in motion or in rain even colder.
But I’m not happy with viscous fan clutch, before I retrofit it with air operated clutch I want to make sure is getting the signal.
Can’t open the attachment low signal right now. Soonest I go home will work on it.
Thanks to all you guys help keep all posted.