Mid vent giving a mix of cold and warm air

I’ve got another issue with my heating / outside cold air…

In a previous post i mentioned that no air is coming trough the center vents.
After physically making them be stuck in the open position a good amount of air is coming trough them now. So far so good…

However, today i noticed that the left vent of the middle vents gives cold outside air, but the right middle vent blows hot one. Outside it was 15c and the left vent gave about 15c cold air and the right one gave about 30c.

This frustrates me quite a bit. The previous owner deleted the entire AC system for some reason. I could have lived with that, if at least i would get some cold outside air (non air conditioned air) But now I’m getting a mix of cold and hot air… sigh

If anyone knows what my issue is, I’d appreciate the help…

Cheers
Marco

Update: I really think the left Blower Motor is broken somehow.

First i thought it was working since i felt lots of air when sticking my fingers into the Blower motor trough the accessible flap.

But today i took the fuses out while the System was on ‘high’ fan speed. after taking the left side fuse out there was no change in sound. After taking the right blower fuse out it went completely silent.

Seems like my left blower is out then? Can it be rebuilt? and is there a tutorial on getting it out?

There is a wealth of information on the old Jag-lovers (jag-lovers.org) site:

https://www.jag-lovers.org/ebooks/view.php?Vbook=xj40&Vsection=9.1

Thanks Mike.

It seems like my blower doesnt need to be rebuilt.
I managed to get it out (yes i my back almost died)

And i hooked 12v battery directly onto the Fan electrodes. It immediately spun up with great speed.

Now i wonder why it didnt work while being in the car…

I opened up the relays and they on the clicking part they look really black. On the internet i cant find any new or used Hella 003 510 34 Relays.

But i managed to find this:

4 Pin 12 Volt 40 Amp DIODE protected relay ALT/RY20-1-02 (altecautomotive.co.uk)

would they also work? (maybe i can remove the middle pin somehow…)

Sounds like it could be the fairly common fuse box issue. Check if you have power on the brown w/blue tracer at the blower. It should be 12v even with ign off. No power = fusebox cracked solder joint

Hi Larry. Ty for your answer

Wouldnt i get a fuse error light in the dash if a solder joint was cracked?

And do you know if that relay i postet is compatible?

Cheers

No you wouldn’t get a fuse error. A fuse box in the footwell comprises two circuit boards, the front board has the fuse holders and if tested can show good across the fuse terminals but the output at the rear can still be defective. Test the brown with blue tracer wire at the blower to see if you have power. As I mentioned earlier, you should have constant 12v on that line even with ign off. Start there and report back.

If the problem is a relay, you can solder an external diode to the pins of a non-diode relay and that will work too. First check if you have power coming in. If you don’t, pull the fuse box and examine the joints with a loupe. The blower joint is near the middle.
If the fuse box has a cracked joint, (very common) you don’t necessarily have to replace it, just reflow the joints. Even replacements could have the same issue, it is a design/manufacturing fault.

Hi Larry

thank you for your answer.
I will check if i have 12v on the brown with blue tracer wire with ignition off. Then i will report back :slight_smile:
Cheers

I’ve replaced the relays with these. They work fine.

Hi Gary

thanks for your post. Cool, I ordered the relay I’ve linked. 4 pieces in case the other blower dies as well… Seems to be the same specs. Same diode direction.

Im already dreading reinstalling the blower into the driver side footwell…
But if i get good airflow it might be worth the hassle

Hey Larry

I checked the power wires for the blower unit you mentioned (2 wires in a round-ish plug)
with igniton on i got 11.9v.

I assume my relays must have been the issue then. I ordered those i linked and hope the unit works afterwards…

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After replacing the 2 relays inside the Blower motor and attaching it, the Blower is working again!

Now i just need to install it back, but I will do that a other day because it will probably break my spirit and back…