No heat when the vehicle in idle. (2006 m35x)

[szh]

The challenge is how to defrost your car when the blower will not engage for 15 minutes?

Ah, but the defrost portion of it works (at least in my car, it does ) - the fan will start blowing air onto the glass immediately, but not through the vents. This gets the windshield clear ... in a bit of time, but it does not freeze me in the process.

Z

[mcalvino45]

No, thats to say i can manually turn it up to high and it will show its on high but it not going to blow any air out cold or hot until about 15-20 minutes or so.

Did you ever get the problem solved, i have an '06 M45 with the same problem.

[PJS3]

I just checked and the my coolant level is pretty low, I will top it up and see if that helps.

I am experiencing the exact same symptoms as you were. Idle = no heat. In motion = heat.

Took it to the dealer this morning. They said it was a low coolant, dirty coolant, and air bubbles in the coolant issue. Quoted me $170 to flush and fill the coolant....

I passed.

I figure I'll add coolant for now and see if that fixes the immediate issue, and then find a shop to do a coolant flush for a little less than an arm and leg.

Car is 300 miles from being out of warranty, so....

[movado750]

No, thats to say i can manually turn it up to high and it will show its on high but it not going to blow any air out cold or hot until about 15-20 minutes or so.

Did you ever get a diagnosis on this problem I have the exact same thing happening with my 06 M35.

Miles

[mcalvino45]

I fixed mine it was the relay.

[seldomseen]

My M wont blow until the engine is heated up. I was assuming it was designed that was to prevent from just blowing icecold air on us. No heat until its actually heated air. Are you sure its just a cold engine block and as you drive its heating up then out comes the heat? or are you stopping warmed up at idle and its shutting down.

This is exactly how the F50 Q45 heater works as well. It's simply how the system was designed in order to allow the engine to achieve safe operating temperature during cold weather.

[NIK_2021]

I had the same problem. It would take like 15-20 minutes in order for me to get heat. Took the car to the dealer and got it taken care off. Don't remember what it was of the top of my head but I can look through my receipts if you'se want. I know they had to replace a few things because they have to do a step-by-step troubleshoot. They even replaced the instrument cluster which I can't think of why they would need to but good thing I have warranty. Total bill was close to $2000. But I only had to pay a $100 deductible.

[movado750]

Well I just replaced the T stat and now it blows hot air good but now it starts blowing cold air at stop lights with in a minute of sitting there.

Now not only does it not turn on for 25 minutes it start blowing cold air at stop lights when not moving. Moving blows hot air.

Nik 2021 could you look on your reciept to see what they replaced?

Thanks...

[movado750]

I fixed mine it was the relay.

Which one did you replace i just went and looked and could not find anything that had anything to do with the blower motor?

[movado750]

I just down loaded the service manual and came to the conclusion that it may be the Ambient Temperature Sensor.

What do you think?

[movado750]

If know one is reading this post that is fine but I hope someone will appreciate this in the future. It gave me a couple of cheap ways to get away from the dealership.

You can read form my earlier posts.

Its all in the coolant!!!! nothing else . I did all the self diagnostic stuff from the service manual all sensors came back good. All motors running good. Everything came back with ok proceed to next step press temp up once.

Came back started reading the service manual more one suggestion under "Insufficient Heat" was flush coolant system. Just got back and it is blowing hot air right from the engine start up and i will be checking it in about 1.5 hours to see if my problem of the blower motor not turning on until 45 minutes.

The service manual is pretty in depth as to check all sensors and it works. These cars have four sensors that are all connected to the Unified meter and A/C amplifier. One of these sensors is a coolant temp sensor the if it does not like the temp of the coolant it will not talk to the Amplifier. Hence, the amplifier will not tell the blower motor to engage if one sensors is not responding or shorted.

I will update in one hours after she has cooled for 1.5 hours.

[mcalvino45]

Not sure if this is related to this post but my blower was only working after I drove for 15-20 miniutes then it worked fine. I found a fan relay "behind" the fuse box next to the emergency brake. let me know if you cant find I will send you pictures. It worked like a charm...

[movado750]

Not sure if this is related to this post but my blower was only working after I drove for 15-20 miniutes then it worked fine. I found a fan relay "behind" the fuse box next to the emergency brake. let me know if you cant find I will send you pictures. It worked like a charm...

If you have pictures that would be great.
I have done all other options. Thanks.

[mcalvino45]

If that sounds like your problem, get part #25230-79942 (dont worry about the vehicle description) and you can sleep good tonight your problem is solved...if you can tell me how to attach a photo I will send you a couple or just send me your email address.

[movado750]

Wowo that would be awesome if that was the easy fix. I started it this morning and let if warm up for 15 minutes and still nothing, no blower running.

I had to take my summer vehicle out in the snow, as it was way to cold to drive 30 miles with no heat.

Thanks a bunch calvin.

[kfk256]

If that sounds like your problem, get part #25230-79942 (dont worry about the vehicle description) and you can sleep good tonight your problem is solved...if you can tell me how to attach a photo I will send you a couple or just send me your email address.

What is the part description and tips to replace......please.

[PNO2NR]

Had the same problem."BLOWER RELAY."Located on back side of fuse block J/B, left of parking brake. Dealer couldn't diagnose! Thanks to this forum, it pointed me in the right direction. To be fair, all diagnostics came up clear, but let's use our brains too. $30 part.

[kfk256]

Hello all,
Can someone please tell me where the blower relay is located (pictures will help) in a 2006 m35x. I looked at the panel next to the foot parking brake, but i only see fuses not any relay. Thanks.

[Ilya]

Relay's are usually in the engine. I believe near the battery is where the relay box is. Take off your covers in the engine bay and it should be clear as day.

[MikesWhiteM]

You might not wish to hear this, but...I just had the exact same issue with my 2007 M45S and tried everything from flushing the coolant, all the way up to replacing the Heater Core. Did the Thermostat, and EVERY other component to the heating system, and wound up replacing the most expensive. Its not a common issue (The Heater Core) I was told, but after it was replaced, the heat is working at all times.