View Full Version : HEVAC
banarcus
31st May 2016, 04:56 AM
Finally plunged in and ripped out my dash so that I can see what's going on with my HEVAC.
I plugged in my EAS Unlock V4 and my left blend door servo isn't moving. Not getting 12v or something.
I ripped out the blend servo. Opened it up and tested the motor inside. I could stall it with my fingers very easily. I had some left over motors from my disco 2 door lock project and used a spare to replace the dead servo motor.
After replacing the motor and lining up the arrows on the wheels, I powered up the HEVAC but it seems the little pot is erratic. I replaced it with one I bought from a company in Germany.
Now the bugger works but it appears to me that the pot that I bought is confusing the HEVAC unit. I'm going to have another play today to see if I can get it to work properly otherwise I'm going to replace the dud one or bite the bullet and buy a new set and be done with it! :mad::mad:
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mtb_gary
31st May 2016, 07:48 AM
The blend flap should also move freely. A fairy common problem due to warpage and dirt ingress.
p38arover
31st May 2016, 07:49 AM
Sorry but you can't place wanted ads in the main forum. You must use the Markets.
TheTree
31st May 2016, 09:41 PM
I found the problem was old grease in the flap pivots, the flaps themselves are soft rubber and can't really warp
Cleanup by scraping off as much as you can and then Inox seems to have done the trick
Steve
Keithy P38
1st June 2016, 01:14 AM
Don't forget to check the relays and fuses for these. Sometimes a dud relay will throw a code on the hevac when there's nothing wrong with the parts themselves.
Cheers
Keithy
banarcus
2nd June 2016, 03:06 PM
It's definitely a dud servo. The motor inside could be stalled by hand. I'm going to try and put back the original motor but with new brushes from one of my new motors.
I'll post up my progress.
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TheTree
3rd June 2016, 06:46 AM
I replaced several motors before I finally took the dash out and did the airbox.
It seems the motors burn out from the extra load when the flaps get stiff
Steve
banarcus
4th June 2016, 10:42 AM
I had a another look at the airbox. The flaps move quite easily but there was plenty of dirt/dust. I'll put that down to the crusty old filters I replaced late last year. They were bent all out of shape and obviously lost their filtering ability.
At the moment, I'm driving around without a dash until I source a second hand single servo or I'll bite that bullet and buy a set of new Britpart ones.
banarcus
6th June 2016, 02:23 PM
Ok. I got scared off by the price of the replacement servos. One mob wanted an extra $28 on top of postage just to ship them to the Hunter Valley. If I were in Sydney I wouldn't have been charged that premium. Anyway...
The troublesome LH blend servo has been fixed. I cleaned up the original motor inside with emery paper. There was still plenty of meat on the brushes. I soldered the motor back in and then tuned the replacement pot that I soldered in.
For added durability, I greased up the servo gears and the rubber o ring that moves on the outer case.
The servo now operates as commanded via the HEVAC controls.
Now to do the other two while I have the dash off..
banarcus
9th June 2016, 03:42 PM
Job done. No more error book. In fact, this is the first time I've had a error free HEVAC screen in 12 months.
https://www.aulro.com/afvb/images/imported/2017/01/786.jpg (http://s469.photobucket.com/user/banarcus/media/Land%20Rover/DSC_0090.jpg.html)
TheTree
9th June 2016, 04:01 PM
Great work mate!
That dash setup looks good, I presume you crafted the plastic bit to mount the HEVAC unit under the switches?
Steve
banarcus
9th June 2016, 06:43 PM
Yep. I build an alloy frame of sorts to support the stereo which my phone mounts on. I use an OBD2 app and have all my music on it. The phone also has a radio tuner plus Garmin navigation.
I chopped out the small cubby hole and clock and carved a bezel of sorts out of bog. You can see the missing switch cover which has the cabin sniffer for the HEVAC. Downside is I miss having a clock.
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