Swapping HeVac Head Units

T

TCubed

Active Member

Posts

991

Location

Surrey

• Apr 19, 2012

• #1

Hi,

I've purchased a new head unit for my P38 climate system because my one has a completely screwed up display which has now irritated me beyond the point of no return. This one is faulty, so a clean change isn't what I'm doing; I'm going to amalgamate the working bits of each to make a functioning unit.
My question: can I freely lug in and swap them into the car without something freaking out?

Thanks!

 

T

TCubed

Active Member

Posts

991

Location

Surrey

• Apr 19, 2012

• #2

I'll add that it's come from a 1999 P38, mine is a 2001 P38. They look the same though.

 

Datatek

Well-Known Member

Posts

45,775

Location

Near Poitiers SW France

• Apr 19, 2012

• #3

There is a difference in the aircon compressor switching between early and late units, as you have a 99 and an 01 you should be OK.

 

T

TCubed

Active Member

Posts

991

Location

Surrey

• Apr 19, 2012

• #4

What about a 1996 one (which is what I've found it says on the back)? All I want to do is capitalise the display bit though, so would there be a difference there?

 

rasheed

Well-Known Member

Posts

1,815

Location

Bangladesh

• Apr 19, 2012

• #5

I'm guessing you'll let us know. :behindsofa:

 

T

TCubed

Active Member

Posts

991

Location

Surrey

• Apr 19, 2012

• #6

OK, things stand as follows, both units are in 3 parts; front, primary circuit board, and the back bit. I need to get the primary circuit board from the one with working display onto mine, but the bulb in the one with working display has gone so I need to change that. Thoughts?

 

Druim

Well-Known Member

Posts

1,734

Location

Denmark

• Apr 19, 2012

• #7

I've just changed my HEVAC unit as the book symbol wouldn't go away and the fan speed button didn't work + every second time car was started the outside temperature reading showed 0 degrees - or 20 degrees lower than actual if the out side temp was above 20 degrees.

Turned out the unit in my 1995 was actually a wrong unit from 1998 hence the temperature fault, someone have changed it to wrong one at some point.
Changed to unit from 1996 and now everything works and no more book symbol - had fault codes read/cleared and haven't returned.

Conclusion yes it really matters which year the unit was built - and that 1995 is compatible with 1996.

Also read about the relay issue mentioned, so check carefully or it may fail...