Power window relays: 4 post vs 5 post?
03-18-13, 10:41 PM
#1
in the OG article for the power window relays:
http://web.archive.org/web/200505170...r_windows.html
dood states that you MUST use "NO NC" relays "NOT headlight relays". wtf does that mean. i digress.
I have a bunch of 4 post relays - lacking the 87a post. He's just wiring the 87 to 87a anyways. how is that different from a 4 post relay?
the relays I have are: "4-pin 30amp 12 volt relay"
. 87
. _
86 | | 85
. |
. 30
will those work? and if not, could someone explain the WHY not the how those relays are required.
Thnx
~Geoff
http://web.archive.org/web/200505170...r_windows.html
dood states that you MUST use "NO NC" relays "NOT headlight relays". wtf does that mean. i digress.
I have a bunch of 4 post relays - lacking the 87a post. He's just wiring the 87 to 87a anyways. how is that different from a 4 post relay?
the relays I have are: "4-pin 30amp 12 volt relay"
. 87
. _
86 | | 85
. |
. 30
will those work? and if not, could someone explain the WHY not the how those relays are required.
Thnx
~Geoff
03-19-13, 01:15 AM
#2
Headlight relays have 5 pins with two 87 terminals. The "NC" relay is a no contact style with 4 pins. The other kind has 5 pins where one is 87a and the other is 87 - one makes contact while off, the other makes contact while switched on. I don't recall exactly which is which, but there should be a diagram on the relay housing and/or package if you bought it new.
03-19-13, 01:23 AM
#3
Headlight relays have 5 pins with two 87 terminals. The "NC" relay is a no contact style with 4 pins. The other kind has 5 pins where one is 87a and the other is 87 - one makes contact while off, the other makes contact while switched on. I don't recall exactly which is which, but there should be a diagram on the relay housing and/or package if you bought it new.
I'm re-writing it as I do the project. He digressed an awful lot in that write up - took me several reads to actually get what was going on.
03-19-13, 03:08 AM
#4
He bridged 85 and 87a together. There are some times when this is ok, depending on what you're trying to do. I did that once to trigger an electric fan from a thermostatic switch. Or was it just a 4 pin? I did all that in the year 2000 so it's been a while.
I haven't hooked up window switches before so I'm not exactly sure his diagram is correct. But my car needs window switches so I might as well hook up relays to go with them. Kinda busy on engine builds at the moment though.
I haven't hooked up window switches before so I'm not exactly sure his diagram is correct. But my car needs window switches so I might as well hook up relays to go with them. Kinda busy on engine builds at the moment though.
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03-19-13, 01:24 PM
#8
Jeff20b good catch - he's actually bridging 87a to 85. I've already re-written his tutorial, taking out the dialogue and putting things in sequence. I haven't yet updated the pics but here's the rough-draft:
https://docs.google.com/document/d/1...it?usp=sharing
I'm going to ponder the 87a / 85 bridge for a bit. I think we can get it going with 4 post switches.
https://docs.google.com/document/d/1...it?usp=sharing
I'm going to ponder the 87a / 85 bridge for a bit. I think we can get it going with 4 post switches.
03-19-13, 03:52 PM
#9
OK so after some study I think i've figured it out. 5-post with bridged ground is required.
the 5-post relay toggles the connection from post 30 to 87a (default) or 87 (when receiving signal from post 86)
So in his wiring diagram, post 87a is ground, and 87 is power. Supposing there are only 2 wires coming out of the window motor - its direction is determined by which way the electricity is flowing. So - double ground (87a on both up / down switch) is off. Connect one relay to 87, other to 87a, window motor goes in that direction. Reverse the connection, ground and power are reversed and motor goes in opposite direction
So to answer my own question - yes 5 post relays are required.
the 5-post relay toggles the connection from post 30 to 87a (default) or 87 (when receiving signal from post 86)
So in his wiring diagram, post 87a is ground, and 87 is power. Supposing there are only 2 wires coming out of the window motor - its direction is determined by which way the electricity is flowing. So - double ground (87a on both up / down switch) is off. Connect one relay to 87, other to 87a, window motor goes in that direction. Reverse the connection, ground and power are reversed and motor goes in opposite direction
So to answer my own question - yes 5 post relays are required.
06-12-13, 01:03 AM
#13
Today I got the window relays wired up and installed. I did them a little bit dfferently in that I used a 12 gauge wire on the + and - and only daisy-chained two relays together, making two sets -- not all four together the way ioTus did. They get hooked up similar to the car's harness in the end so it probably doesn't matter too much, but I felt doing it my way was the better choice for me as I've hooked up relays but had never done anything quite like this before.
The roll up/roll down speed improved from 5 seconds to 3.5! These windows haven't moved since 1997 so that's my excuse.
What are your speeds like?
The battery was at 12.3 volts but the voltage through the stock wires was only 12.02 to 11.9 at rest (I imagine it dropped down a lot when a window is in motion). I could see the volt gauge dip and the dash lights would dim a bit under use.
So I rewired it!
The thick 12 gauge wires helped a lot. Now I don't see the gauge dip and the lights don't dim anymore. Plus a whole 1.5 seconds faster is nice. I'm sure once it's running and the alt is charging at like 14 volts or whatever, that they'll move even quicker. Hopefully with use, they'll speed up even more.
The roll up/roll down speed improved from 5 seconds to 3.5! These windows haven't moved since 1997 so that's my excuse.
What are your speeds like?The battery was at 12.3 volts but the voltage through the stock wires was only 12.02 to 11.9 at rest (I imagine it dropped down a lot when a window is in motion). I could see the volt gauge dip and the dash lights would dim a bit under use.
So I rewired it!
The thick 12 gauge wires helped a lot. Now I don't see the gauge dip and the lights don't dim anymore. Plus a whole 1.5 seconds faster is nice. I'm sure once it's running and the alt is charging at like 14 volts or whatever, that they'll move even quicker. Hopefully with use, they'll speed up even more.
06-12-13, 02:11 AM
#14
Doesn't matter if you daisy 2 or 4 together. Connecting 86 and 87 to 12v is still in parallel whether you did it at the relays or 12v on the car. If you didn't daisy you just wasted more wire. 12 AWG is a bit of over kill considering you power and ground connections are less than 6 feet max.
06-12-13, 09:29 AM
#15
Just so everybody knows the purpose of the fifth poll (87A) is to invert the polarity of the 12v going to the motor. The way a Bosch style relay works is that when the relay is not energized(no 12v to 86) then pin 30 (the output) is connected to 87A(NC = Normally Closed) which is ground... So on the relay that's not energized the output will be???? GROUND 
. When you supply 12v to pin 86 you energize the relay connecting pin 30 (out) to pin 87 (NO= Normally Open) which will give you 12 v out of that relay to your motor. The factory switch does this all by itself, when you select up the red wire (in the diagram) will have 12V and the green wire will have ground. Selecting down the reverse becomes true because that's how you control the direction of the motor by controlling the polarity. The reason this mod is great is that after 20-30 years the contacts in the switch are worn creating a resistance causing a lower voltage to the windows motor...
See the diagram below:
. When you supply 12v to pin 86 you energize the relay connecting pin 30 (out) to pin 87 (NO= Normally Open) which will give you 12 v out of that relay to your motor. The factory switch does this all by itself, when you select up the red wire (in the diagram) will have 12V and the green wire will have ground. Selecting down the reverse becomes true because that's how you control the direction of the motor by controlling the polarity. The reason this mod is great is that after 20-30 years the contacts in the switch are worn creating a resistance causing a lower voltage to the windows motor... See the diagram below:
