P38A HEVAC adjustment?

kermit_rr · Feb 13, 2021

This is really getting to me now!! When the engine is fully up to temp, the heater only ever blows warm, even when both sides set to HI.
There's no book symbol and no errors, calibration has been done and nanocom shows 100% when set to hot, but it feels like I in reality the flaps are only at 90%.
When my driver's blend motors wasn't working, I took the motor off and pushed the flap to fully open which would burn my legs after a few minutes, so I know the heater doesn't have any airlock or other blockage.
Any ideas? I'm fresh out

kermit_rr · Feb 13, 2021

Just to add.. once up to temp, it does keep a steady temp in the cabin

pwood999 · Feb 13, 2021

Using Nanocom, check the temp sensor on the pipe is giving sensible readings. Also check the Aspirator & Evaporator temperature readings. All three are used for the L & R temp control flap settings.

kermit_rr · Feb 13, 2021

pwood999 said:
Using Nanocom, check the temp sensor on the pipe is giving sensible readings. Also check the Aspirator & Evaporator temperature readings. All three are used for the L & R temp control flap settings.

I don't know what aspirator and evaporator are but sound like AC related? Currently non functional, maybe that could be a problem?

Marshall8hp · Feb 13, 2021

The aspirator is the little fan arrangement under the clock. It reports what it sees as the cabin temp to the HEVAC. It fills up with fluff and crud over time which can stop it working or it can report a higher cabin temp than actual due to the fan slowing down and the sensor being insulated by fluff. Take it out and clean it. When you put it back, power it up so you can see if the little fan is working and not burnt out from being stalled by fluff and crud.

pete12345 · Feb 13, 2021

Not sure weather this would make any difference but could the antifreeze make a difference I’ve to week

Marshall8hp · Feb 14, 2021

kermit_rr · Feb 14, 2021

pete12345 said:
Not sure weather this would make any difference but could the antifreeze make a difference I’ve to week

The only change has been putting the blend motor back in place

pwood999 · Feb 14, 2021

Calibration uses motor stall points to find the end stops. Maybe the motor simply stalls just before the actual end of flap movement, so your calibration doesn't match what you can achieve moving the flaps by hand ?

P38A HEVAC adjustment?

kermit_rr

Very

kermit_rr

Very

pwood999

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kermit_rr

Very

Marshall8hp

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pete12345

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Marshall8hp

Well-Known Member

kermit_rr

Very

pwood999

Well-Known Member

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