power vent - switch wiring ?

[Quint4]

The windshield on my 290da has a vent in the center. It is opened and closed by an electric actuator operated by a switch on the dash. It does not work. I bypassed the switch and can get the actuator to operate so I figure the switch is bad. I bought a new switch and it still doesn't work...darn I was hoping to cross this off my list ! Has anybody dealt with these switches ? I can tell the previous owner has messed around trying to fix this and I wonder if the switch is wired right. It has 8 lugs on the back and is on-off-on . I guess it reverses polarity to move the actuator out or in. I put the wires back on just like the old switch...I am pretty much stumped at this point. Here are pics of the switch.

 

[sr360aft]

I am going to venture a guess the wiring is incorrect. The Green/Green/Green label indicate where the ground/bonding wires go. Looks like you have a + hooked to one of those. Middle picture above has 2 + wires going into what appears to be feed for one of the directions

 

[wish2fish]

could they have used at relays to reverse the polarity of the actuator? I'm not familiar with a switch that can reverse polarity. How many wires at the actuator?

Why don't you email Carling at their site to get some info on the original switch. www.carlingtech.com

 

[Quint4]

thanks for responses...I had contacted carling before posting...they were not any help...I am going to use my multi -meter and some more trial & error to try and figure out the switch. There is no relay in the circuit and only two wires from the actuator motor ( red & black ).

 

[jrcinnh]

I can't read a part number on the image so I'll give you my best guess.

The standard way to make a reversing switch is using a double pole double throw (DPDT) switch. It has 6 connections. Since you have 8, I'm guesssing the other two light the lamp in the handle.

A DPDT switch has two identical poles. Each pole has two throws "on" positions and sometimes a center "off" position. Each pole has three connections, a common and two switched. When the switch is up the common connects to one switched connection and when it's down it connects to the other one. In the middle it connects to nothing.

So you have 6 connections, I'll make up names: left-common, left-up, left-down, right-common, right-up and right-down.

So to make a reverser:

Connect the left-common and right-common to the motor plus and minus. The polarity doesn't matter for now.

Connect battery plus (12 volts) to the left-up and right-down
Connect battery minus (ground) to the left-down and right-up

If the switch works backwards, swap the motor leads.

 

[Quint4]

thanks again guys...I have been busy at work and will try your suggestions soon and re-post.

 

[Quint4]

I finally got around to revisiting my switch problem. It was wired wrong. I figured it out thanks to jrcinnh. I took the switch apart to look at the contacts. I then drew out schematic using jrcinnh's post and hot damn...I fixed it ! What a relief to take this off of my to do list !
Thanks !

 

[wish2fish]

Quint,
great to hear. I'm interested in how this switch works so could you possibly post your schematic for educational purposes?

 

[Quint4]

Sure..give me a few days to put it into postable format. I was in Ripley this weekend for a family event...came down 52 from Cincy....river looked good !

 

[jrcinnh]

glad I could help

Too bad you had to take the switch apart. I tried to find a good pin-out diagram but the Carlingswitch website is disappointing.