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-   Diesel Discussion (http://www.peachparts.com/shopforum/diesel-discussion/)
-   -   Does manual climate control use any vacuum? (http://www.peachparts.com/shopforum/diesel-discussion/328921-does-manual-climate-control-use-any-vacuum.html)

10fords 11-03-2012 11:38 AM
Does manual climate control use any vacuum?
 
I disconnected all of the vacuum lines on my 1981 240d except the one to the shutoff for the ignition as I have some leaks in the locking circuit. I did this a few months ago while it was hot so I hadn't used the heater or defroster at all, and now my blower motor doesn't come on at all. I checked the fuse and it is fine. Does the system need some sort of vacuum to activate the blower motor? I guess it is possible that the blower motor went tits up, but it worked fine last spring. Any suggestions?

kerry 11-03-2012 11:44 AM
I doubt it needs vacuum. The manual climate control on my 409d didn't. Just look at the main vacuum line. Is there any line coming off it other than the shut off and the doors? A climate control line would be green.

Biodiesel300TD 11-03-2012 11:53 AM
No it's all cable operated vents and electric blower motor. But like kerry said if you do have some climate control vac you will have a green vac lines coming off the main vac line in the engine bay.

Did you pull the fuse or just look at it? I've seen these fuse get little circles cut out of them from the clips that hold them. The clip slowly cuts a little hole in the end of the fuse, and leaves poor contact. So make sure you pull it out and inspect it if you haven't. If you do find this situation, make sure to find the cut out bit. You don't want it floating around in the fuse box.

10fords 11-03-2012 12:12 PM
There is a green vacuum line at the firewall that I disconnected. I assumed it was for the climate control to switch between the various vents. I hooked the vacuum tester to it and it does not hold vacuum so I left it unhooked. Would that keep the blower from coming on? PS- I checked the fuse with an ohmmeter after replacing it just in case that was the problem. According to my FSM I have the 3rd version of manual climate control.

franklynb 11-03-2012 12:14 PM
Quote:
Originally Posted by Biodiesel300TD (Post 3042015)
No it's all cable operated vents and electric blower motor.
The later vintage of "manual" used a vacuum switch with a defrost position rather
than cables to operate the air doors.

Its more likely that you have a burned out speed resistor network.
which is mounted in the left defroster vent on some 240D models, on the fender well
in others. I'm note sure where the MY break is, since I've seen 1979/80 models with
either mount type. It probably depends on airbox vendor, Siemens or Behr.

Or a bad switch, if you've hot wired the blower and know it works.
You can jumper the four pin connector at the blower cable to jumper
out the lower speeds and get a single high speed blower.

Doktor Bert 11-03-2012 12:25 PM
Quote:
Originally Posted by kerry (Post 3042006)
The manual climate control on my 409d didn't....
A 409d????

I have never heard of one. What is it exactly??? Are you referring to a T1????

10fords 11-03-2012 12:26 PM
Quote:
Originally Posted by franklynb (Post 3042026)
The later vintage of "manual" used a vacuum switch with a defrost position rather
than cables to operate the air doors.

Its more likely that you have a burned out speed resistor network.
which is mounted in the left defroster vent on some 240D models, on the fender well
in others. I'm note sure where the MY break is, since I've seen 1979/80 models with
either mount type. It probably depends on airbox vendor, Siemens or Behr.

Or a bad switch, if you've hot wired the blower and know it works.
You can jumper the four pin connector at the blower cable to jumper
out the lower speeds and get a single high speed blower.
Thats my next step to start fooling with. I just want to make sure that vacuum isn't the problem before I start chasing my tail as it worked before I disconnected the vacuum, albeit many months before.

franklynb 11-03-2012 12:49 PM
Quote:
Originally Posted by Doktor Bert (Post 3042028)
A 409d????

I have never heard of one. What is it exactly??? Are you referring to a T1????
http://franklynb.home.mindspring.com/_617/409D.JPG

Pretty sure, although I can't find the high resolution side shot to read the badge.

kerry 11-03-2012 03:39 PM
Yes, 409d is a van with a 617 engine. Doesn't look like the van pictured above though. It's the T1 body style (I think that's the correct designation). The van pictured above is the larger van versions.

jay_bob 11-03-2012 06:06 PM
Later 240Ds have one vac pod, it is actuated by the detent on the a/c temperature wheel.

There is a vacuum solenoid on the far right side under the dash, it uses the green hose from the engine bay to shut the recirculating damper.

10fords 11-04-2012 11:15 AM
It looks like I have low speed on the blower, but no high speed. I was trying it with the engine on and I couldn't hear the blower! So what could cause no high speed? The switch?

jay_bob 11-04-2012 12:05 PM
Low speed but no high speed is bad switch or bad connection at the resistor.

240D blower control is very simple.

The battery voltage goes to the resistor. The resistor is in two sections. The other end connects to the motor.

The switch connects a couple contacts across the resistor, these short out one part of the resistor for medium or both parts for high. On low the entire resistor is in the circuit.

10fords 11-04-2012 12:15 PM
Quote:
Originally Posted by jay_bob (Post 3042490)
Low speed but no high speed is bad switch or bad connection at the resistor.

240D blower control is very simple.

The battery voltage goes to the resistor. The resistor is in two sections. The other end connects to the motor.

The switch connects a couple contacts across the resistor, these short out one part of the resistor for medium or both parts for high. On low the entire resistor is in the circuit.
Good stuff- thanks! I'm gonna open it up today and check it out.:D

10fords 11-04-2012 01:09 PM
Just took the blower out (which was a piece of cake!) and I can't locate the resistor(s)? My FSM shows them in the blower housing under the cover that the plug goes into, but it looks like a straight connection to me. It is a Siemens blower.

kerry 11-04-2012 01:36 PM
Quote:
Originally Posted by franklynb (Post 3042026)
The later vintage of "manual" used a vacuum switch with a defrost position rather
than cables to operate the air doors.

Its more likely that you have a burned out speed resistor network.
which is mounted in the left defroster vent on some 240D models, on the fender well
in others. I'm note sure where the MY break is, since I've seen 1979/80 models with
either mount type. It probably depends on airbox vendor, Siemens or Behr.

Or a bad switch, if you've hot wired the blower and know it works.
You can jumper the four pin connector at the blower cable to jumper
out the lower speeds and get a single high speed blower.
Have you looked in these locations?


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