06 rear blower won’t cut off with ignition

I’ve got a couple problems all of a sudden with my 06 expy limited with electronic front temp control

the front blower only works on high, which my Google fu tells me is the blower control module

but here’s the weird one:
the rear blower speed control works ok, but the blower will not shut off when you turn the ignition off

it has to be switched off at the control on the ceiling

I remember a few years ago, I had the same problem with the front blower speed control. It was a $78.00 relay that is behind the glove box. Didn't take long. If you need more info, I might be able to find it in the shop manual.

I'll pull the wiring diagram on the aux blower and see if I can find something.

I pulled the wiring diagram. It appears there is a rear blower motor relay similar to the front blower speed control. If the relay fails closed, it would create the problem. According to the wiring diagram, it is feed with a line that is "Hot all the time."

Here is the diagram.

thanks
i figured its gotta be a relay stuck in the "on" position which seems like a fire hazard to me.


any idea where this relay is located?

I got a used front blower module at a junkyard for $25 and cured that.

does the rear one have a module?

The Aux relay box is located behind the trim panel and just in front of the right rear tire hump. Forward of the rear HVAC box itself.

Hamfisted said:

The Aux relay box is located behind the trim panel and just in front of the right rear tire hump. Forward of the rear HVAC box itself.

Click to expand...

thanks for the pic!
I removed the panel so I can access the relays, but the relays are engaged all the time, even with the ignition switched off.
if I remove them , they click off, and if I plug them back in they click on again.

I pulled fuse 107 in the front passenger kickpanel to kill the power to the rear blower and keep it from draining the battery.

the DVD player is also making weird noises all the time.
Im guessing there is another larger relay up front or under the hood that powers the three relays in the back for the AC?

anyone know where that relay is?

The rear blower relay gets it's power from fuse #107 there in the fusebox at the passenger kick panel. Fuse 107 is HOT all the time. It is the only one in that segment that is HOT all the time. If voltage is getting past that rear blower relay, it is the relay itself that is sticking. Try another relay in that spot.

Hamfisted said:

The rear blower relay gets it's power from fuse #107 there in the fusebox at the passenger kick panel. Fuse 107 is HOT all the time. It is the only one in that segment that is HOT all the time. If voltage is getting past that rear blower relay, it is the relay itself that is sticking. Try another relay in that spot.

Click to expand...

none of the three relays in the rear are sticking.
ive swapped them around, and I can hear them clicking when they are plugged/unplugged.

in the rear, the three relays are arranged with two next to each other and the third in another row by itself.
this single one apparently controls the other two, if i unplug the single relay the other two no longer click. but the relay in the row by itself is on all the time even with the ignition off.
and that relay is engaged even with fuse 107 pulled.
where does this relay get its power?

I can hillbilly engineer around this, by installing an additional relay controlled by the ign switch, but somethings wrong, this relay should not be getting a signal to engage all the time.

the control on the roof and on the rear of the console work, and will turn the blower off, but it should go off when the ign is off

Yeah, should only run with the key in the RUN position. I'll dig into it further and see what I can find.


Can you post pics of what you're seeing ?

Hamfisted said:

Yeah, should only run with the key in the RUN position. I'll dig into it further and see what I can find.


Can you post pics of what you're seeing ?

Click to expand...

lemme try with the pic.

the relays in the rear, the one that is powered by fuse 107, its trigger is a yellow wire with a red stripe , that wire is always hot.

i tracked the wire and it comes up front and bypassses the fuse box and goes tward the center of the dash. thats as far as Ive gotten so far.

and ive not had any sucess in finding a wiring diagram online.