Power Window Relay Setup

[John Salla]

Hello All,
I am a new member to this organization. I am excited about learning and contributing. Right now I have an automotive electrical problem I have been dealing with for the last month or so. I need some help. I have spent many hours trying to figure this out myself. Here is a description of the problem along with some important attachments.

I am trying to implement what I understand is a common power window relay setup in my 1987 XJS Hess & Eisenhardt Convertible. I have tried using two switches, a 5 pinch switch that was called a dpdt switch although I am not sure it is one and a 6 pin dtdp switch. Below are the wiring diagrams for the relay setup and the two switches.

If I apply positive and negative 12 volts to the wires going directly to the motors, all of the windows move up and down providing I reverse the positive and negative wires.

The driver window worked fine for a day using the 5 pin switch, but now when I hook up that same switch, the window does nothing. I tried installing a new circuit breaker, thinking that may be the problem, but nothing changed. I thought the 6 pin dpdt switch would solve all of my problems but none of the windows move at all using this switch.

I have double checked my wiring to insure that I have the wires connected as is set forth in the diagram, a diagram that was prepared by someone else, a diagram that I have seen several times set forth by different authors as the way to set up a power window relay system.

I suspect there is a way to troubleshoot this system. Unfortunately, I do not know how

.

So, if you can make some suggestions, provide counsel, advice and/or guidance, I would greatly appreciate it.

Thanks,

John

 

[MikeMl]

Hi John,

It appears that the switches are not rated for the current that the motor requires to start and run, so all of the actual motor switching has to be done by two relays per motor, and all the switch does is apply power to an up-relay coil, or a down-relay coils?

So far, so good?

Next, we need to determine what happens when the motor reaches the ends of travel. Is there a limit switch when the window arrives at the stops, or does the motor just stall?

Finally, are you up to following an electrical schematic, or do you need to be fed a picture, showing every physical wire you would have to connect?

 

[bwilliams60]

Hey Mike,
Good to see you on this forum. You always provide good feedback on the other forum. This circuit and most in the automotive industry do not have limit switches and rely mostly on the fact that when you reach the limit, you will let go of the button. After that, the motor will have a thermal limiter or current limiter (circuit breaker) built into the unit but rarely dos it ever get to that point. This is an odd setup as most control power and ground through th master switch (drivers) but this setup will work as well. Let's see if we can get the OP fixed up on this.

 

[John Salla]

Hi Mike and bwilliams. Thanks for responding to my posting. Please forgive my ignorance, but am I the "OP"? If so, I am much appreciative that I am going to get your help on this. I cannot figure this one out. Please advise and counsel, and I will gladly follow through. Look forward to your next posts.

To answer your question Mike, I usually am able to follow an electrical diagram. I followed the one that I attached to my posting.

John

 

[KeepItSimpleStupid]

"The OP" is the "Original Poster.

==

Some terms:

The second switch ( 6 terminals) switch can be called:
A DPDT center-off switch (DPDT= Double pole, double throw)
It can also be descibed as a DPDT on-off-on switch.

The crossed outer contacts is representative of a reversing switch. The center terminals are the common contacts. So, in the center, there should be no power. In one direction, voltage is routed out and in the other direction, the DC has reversed polarity.

Voltmeter tests such as:
1. No voltage out in the center position
2. Voltage out in one position
3. The polarity reversed in the other.

With the DPDT switch, the terminals that are closed are opposite the handle, so it's like follow the handle to the back of the switch.

Without power, you can check resistances.

When you have a load of some sort, you can check for voltage across the switch. Interpreting that and measuring correctly might be difficult for the novice.

 

[MikeMl]

Try this:

Relay pins:

Wiring:

Switch is center-off, momentary, spring-return, SPDT

 

[cowboybob]

Welcome to ETO, John Salla!

The old Jags (and many others), like yours, originally had switches only (no relays) to operate their electric window regulators. These frequently suffered from overloading (as noted by MikeMI, above) that resulted in damage to the switches. They did work OK, though, just not as long as what we'd expect these days.

Do you have and can you use a test meter, such as a VOM or DVM? One of these will greatly help you in diagnosing your problem(s).

Do you know, for sure, what is your current wiring configuration?

Some rather simple tests, once we figure out your current wiring configuration is, will be very useful.

There is a ton of helpful info about the window operation (both stock and upgrades) of your car, starting at the bottom of page 602 here: http://www.jag-lovers.org/xj-s/book/XJS_help.pdf

 

[bwilliams60]

Lets keep this simple. If you are using the above wiring diagram, do each of the relays "click" when you actuate up or down motion. I want to establish whether this is on the control side or the load side of the relay.

 

[John Salla]

Thanks for all the help. Yes, I can use a multimeter, and yes I am very familiar with Kirby's XJS book. And yes, I understand resistance and continuity and know how to use a multimeter to test for them. Don't get me wrong though when it comes to electricity I consider myself not much more than a novice.

Its good to see that someone is familiar with Jaguars, especially the XJS. I am attaching the wiring configuration of my windows before I added the relay setup.

Mike, thanks for the diagram of the new setup. You also diagram a relay at the top. You are just showing how the Bosch relay works, am I correct? As far as the diagram for the new setup with single pole double throw switches, that diagram may be out of my league, but give me a day or so with it and I can probably figure it out.

KISS you say there should be no power in the center pins of the double pole double throw switches. If you look at my wiring diagram for the DPDT switches, there IS power in the center. I did much research before I adopted the wiring diagram for the DPDT switches and there were many websites with power in the center on the DPDT switches for power window applications. So, is my diagram wrong, and if so, what is the correct way to wire the DPDT switch?

Look forward to hearing from you.

John

 

[bwilliams60]

We can do this the long way or the short way. Does the relay click when you turn the ignition switch on? If yes, check for voltage with reference to ground at pin E. Check using a load such as a headlight. If no click, check for voltage at WK wire of relay. use headlight where possible

 

[MikeMl]

Lets keep this simple. If you are using the above wiring diagram, do each of the relays "click" when you actuate up or down motion. I want to establish whether this is on the control side or the load side of the relay.

In my diagram in post #6, relays are not actuated unless the center-off switch is moved off center.

I also do the relay coil switching on the ground side of the relay coils, which is a bit safer than switch the 12V to the relay coils.

 

[KeepItSimpleStupid]

KISS you say there should be no power in the center pins of the double pole double throw switches.

Well, I meant to convey that there is no power to the motor when the switch is in the center OFF position.
AND the is probably a correction, If the switches are momentary they would be designates as a DPDT (on)-off-(on) switch or a DPDT center off momentary in both positions. "none" is used if there is no center off position.

Sorry for the confusion.[/quote][/quote]

 

[bwilliams60]

Maybe I'm missing something. Is this car actually wired up right now or is this something you are trying to wire up. My understanding was that it was a working unit and now it is not.
Either way, you can separate the load side from the control side to speed up diagnosis. If the relay clicks, we probably have a load side problem. If it doesn't, more than likely a control side problem. Could be both but not likely. Need to know if this is existing circuit like diagram in post #9.

 

[John Salla]

To All:
Let me clarify something. I am the OP. The car is now wired according to the diagram in my original posting. The diagram I posted in posted in posting 9 shows the factory wiring of the windows. The diagram is the original posting was a relay setup for a different car. I adopted it for my car since the factory wiring appears to be the same. If you compare the diagrams. you can see both diagrams have circuit breakers before voltage goes to the switches. I do not want to use the Jaguar factory wiring setup because it is a bad setup. The windows go up very slowly. Many owners of the XJS switched to the relay setup I posted in the original posting. I want to use a relay setup as set forth in the diagram in my original posting.

As I said in my original posting, the relay setup worked for a day for one window with a 5 pin switch and then stopped working. Right now, whether I use a five pin switch or a six pin DPDT switch none of the four windows will move when I press the switches. I tested for and I have 12 volts at the switches. I tested for and I have 12 volts going to the relays. I tested all of the relays and they are all working properly. I tested all of the motors and they are all working. I put in a new circuit breaker. I tested my grounds and they are all good. When I press a switch, a relay will click but only under a certain condition. I will get back to you shortly with that condition.

Again, sorry for my ignorance here, but could someone please explain to me what is a control side problem and what is load side problem? My guess is a control problem has to do with the switches and a load problem has to do with the motors. Am I correct?

Thanks again to all.
I look forward to your next communication.
John

 

[bwilliams60]

A relay consists of two circuits. Control (coil) and load (switch).
Generally if you look at the control circuit, you will have B+, a fuse or CB, a switch, a coil of wire in the relay and ground. When the switch is closed (continuity) (doesn't matter ground side or hot side), current will flow through the coil of wire and create an electromagnet. When this occurs, the switch portion of the relay will "click" into position and either close or open a circuit, depending on how it is set up.
The second part of the relay (the switch as mentioned above), will have B+, perhaps a fuse or CB, a load, and B- or ground in it's circuit.
If you hear a click when the relay circuit is energized, it generally means that the first part of the circuit is working (control). If you do not, go back to line 2 and figure out which part of that is not working.
If you hear a click but nothing is happening with the load (in your case, the motor), then you can generally look into a problem with the load circuit as outlined in line 4.

If that is your existing schematic at the top, I would check for B+(87) and B-(85) at each of the relays using a load device of some sort. Perhaps a motor. This will indicate the integrity of the wiring. A test light or multimeter will not suffice.

Before the pundits jump in on my relay explanation, it was only meant to be a brief explanation of how a relay works.

 

[KeepItSimpleStupid]

B+ shows bwilliams age. Back when radios had A,B and C batteries. For transistors we now have Vcc, GND, Vee. For cars we USED to have BAT, IGN and GROUND,

The Bosch relay has lots of wierd numbers: **broken link removed**

 

[KeepItSimpleStupid]

In post #9 if you take 3 and A as being the back of a DPDT switch, forget it. It'sin the text as to how it behaves.

NOa2.....Ca.....NOa1
x
NOb2,,,,,Cb....NOb1

If you were looking at the back of a DPDT switch, you would see 6 terminals. I labeled them NO and C for Normally Open and Common
a and b are opposite isolated sides of the switch,
1 and 2 are the positions of the switch.

e,g,
*************1
.............@******O
*************2

Think of the O as a pivot and the @ as a common contact. This ATTEMPTS to show one switch.
In my ersatz ASCII ART on a BBS, ignore the periods. They hold a place.

 

[John Salla]

Hey Guys,

Thanks for all the great information.

Kiss I have read many articles and watched many videos about relays but the one you referenced is one of the best. I printed it out and put it in my reference file. The information you have in posting 17 is way way over my head. Sorry but I don't understand any of it.

Mike, I can't read that diagram in posting 6. You have blue lines with numbers 80, 86, 87, 87a, and 88 and two white boxes with information inside. I think the wires for the lines with numbers 86, 87 and 87a would come from my relays but I don't know where the wires for the lines with the numbers 80 and 88 come from. I also think that one white box show what happens when you press the switch for the window to go up and one box shows what happens when you press the switch for the window to go down. I don't know what the 1N4001 means. I wish I wasn't so ignorant, sorry. BTW, you hit the nail on the head evaluting the diagram I posted. With respect to the switches, they are rated for 30 amps. So, when you say they are not adequate when I believe the motors use 5 amps, I am not sure I understand.

bwilliams you say "if you hear a click but nothing is happening with the load (in your case, the motor), then you can generally look into a problem with the load circuit as outlined in line 4." Please tell me where is line 4.

So there it is. Now, you all know what you are dealing with. I do want to further my knowledge of electronics.

I am selling my house, and today I have to do some corrective work requested by the buyers. Hopefully I will get it done today, and I can get back to you on under what circumstance(s) the relay(s) click when I press the switch.

Have a good day.

 

[KeepItSimpleStupid]

RE: post 17. One of the diagrams shows a 6 pin switch as 2 rows of three, BUT inside that block is a schematic with diagonal wipers which in no way represents the external physical terminal connections of a normal DPDT switch. If you followed a this wire goes here, and the internal schematic is NOT representative, you could have a problem. I've never seen switch arranged like that, but that does not mean that it doesn't exist.

The article mentions the "wierd" numbering of the Bosch standard automotive relay: 80, 86, 87, 87a, and 88

 

[bwilliams60]

B+ shows bwilliams age. Back when radios had A,B and C batteries. For transistors we now have Vcc, GND, Vee. For cars we USED to have BAT, IGN and GROUND,

The Bosch relay has lots of wierd numbers: **broken link removed**

LOL, I may be showing my age but you can read a lot more into this if you have the background, which makes me think you are young and cocky. You see the car is an older car and the diagram uses older language. Perhaps you don't understand it, not sure. One thing I do know is that often times, electronics types tend to make things a lot more difficult than they should be. This is a simple circuit, not rocket science and for the amount of posts on here and time taken, should be fixed already. If you know much about cars, then you would know that circuits with relays can be mostly diagnosed right at the relay. The OP wanted simple answers, I gave them to him.
At this point I think I will step out and watch this thread. Should be interesting to see how long it takes to fix it.
KISS - KEEP IT SIMPLE STUPID
By the way, I do know what Vcc, GND, IGN etc means in electronics. I studied it as well.