[paulm]

Man, lately it seems like everything that I touch goes wrong.....

FYI, 67 RS with new front light harness, new under dash harness, new diode, etc.

Anyway, the breaker on my relay board keeps popping. I disconnected the RS motors, limit switches, headlights and parking lights to try and track down the issue. Even with everything disconnected (except the relays) when I pull the headlight switch (Ignition off) the breaker pops.

Looking at it further, what I've found is that the relay (#2 maybe) that has the two black wires connected to the "common" terminal seems to allow a bunch of current to flow once it is connected. So my pea-brain says that there is too much flow across that relay from the dark blue wire to ground.

I'm no electrical genius, but I ain't that dumb neither....Anywho, I'm scratching my head trying to figure out what would "slow down" the current flow so that it would stay under 10 amps and not pop the breaker. The flow across the relays is pretty simple??? Relay one is fed from the breaker and when the light blue wire is energized, the relay switches and the orange wire feeds the dark blue wire which feeds relay two (which switches because of the light blue wire being energized) which then finds ground from the black wire on the common terminal.

Blah, blah, blah....any input?

 

[Everett#2390]

Are you trying to say the relay coil path or the relay contact path is drawing too much current?

One way to slow down current is to open the circuit.

 

[paulm]

Sorry, there are five wires on each relay. Two (light blue and brown, light switch and acc ignition) are used to switch the relays. The other part of the relays (three wire plug) have the common, open and closed wires. When the light blue wire has power (which switches the relay) the dark blue wire has a direct path to the common wire which is ground and it pops the breaker.

My problem is that I don't understand why that much current is flowing through the relay to ground.

 

[Everett#2390]

I think what you are trying to explain is the light blue is power, brown is ground and these two energize the relay to turn ON the motors in one direction.

You say the dark blue has power and goes to ground via the common wire. This why it trips the breaker.

I don't have schematic in front of me, but, the common terminal, C, should always have power on it, regardless of relay energized or not. One terminal on the relay is NC, Normally Closed. I would think this would be lights off, to close the doors and the limit switch kills power to the relay when the stroke is finished , or door is closed.

Now, you turn on h/lamps, energize the relay, contacts C & NO, Normally Open, would contact and this power would turn the motor to open the doors, through common terminal C. The motors are grounded at there respective locations.

Unless, there are only two wires from the door motor, then each relay is changing the polarity of the motor to open & close the door, then battery power is supplied via term C and NC to go in one direction, then switches polarity for other direction, NO and C, in that order, Term C changes polarity along the other term of choice.

Clear as mud, eh?

 

[paulm]

Check this out....

http://www.retro-electro.net/FAQ.html

This has the diagram as well as what wires go to which posts on each relay. Maybe this will help you to understand what I am saying....


P.S. I am at a loss as well, when there are ground wires to the common terminal.

 

[Everett#2390]

Thanks for the diagram. Man. was I ever off base!!!

I'll look into it and get back.

 

[Everett#2390]

In viewing the schematic provided, relays are not energized:
With the radiator support harness unplugged, this leaves the relays in circuit. Power is fed via ckt brker through R1 NC contacts. Power out the green wire to R2, NO contact. On R2 as labeled, its wrong. Terminal should be labeled NC.

R2 has to be energized to complete the path to R3 NC terminal with R3 Com having the black wire. SO, The brown wire on R2 at the "as labeled" NO terminal should be on the other contact of R2, the "as labeled NC contact"
OR
R2 is wired wrong. Remove the brown wires from the one contact of R2 to the other contact. Thereby, removing the complete circiut through R2 to R3 NC to ground. Make sure the green wire to R2 COM does go to Com on the relay.

 

[paulm]

In viewing the schematic provided, relays are not energized:
With the radiator support harness unplugged, this leaves the relays in circuit. Power is fed via ckt brker through R1 NC contacts. Power out the green wire to R2, NO contact. On R2 as labeled, its wrong. Terminal should be labeled NC.

R2 has to be energized to complete the path to R3 NC terminal with R3 Com having the black wire. SO, The brown wire on R2 at the "as labeled" NO terminal should be on the other contact of R2, the "as labeled NC contact"
OR
R2 is wired wrong. Remove the brown wires from the one contact of R2 to the other contact. Thereby, removing the complete circiut through R2 to R3 NC to ground. Make sure the green wire to R2 COM does go to Com on the relay.

OK, so the brown wire is possibly on the wrong contact on R2....I'll try that, it doesn't seem impossible that my brand new harness has the brown wires in the wrong connector of the plug.


Staring at that diagram, I can't wrap my brain around what happens when there is power on the light blue wire. Power to light blue switches R1 so that the orange wire feeds the dark blue. The light blue wire also goes to R2 and R3....What happens to R2 and R3 when there is power to the light blue wire?

 

[Everett#2390]

OK, so the brown wire is possibly on the wrong contact on R2....I'll try that, it doesn't seem impossible that my brand new harness has the brown wires in the wrong connector of the plug.

Yes, I find it hard to believe also, but could be a problem area. You might take your DMM and do an ohm check from the circuit brkr to ground and look for (correct results) an open. Otherwise, the wire may be switched in the socket.

Staring at that diagram, I can't wrap my brain around what happens when there is power on the light blue wire. Power to light blue switches R1 so that the orange wire feeds the dark blue. The light blue wire also goes to R2 and R3....What happens to R2 and R3 when there is power to the light blue wire?

Let's start over. ACC sw is closed, power thru diode, thru connector, brown wire to R2 & R3 coils. Ohtere side of R2 & R3 coils to R1 coil tie point, lt blue wire, thru connector thru tie point at h/lamp sw thru dimmer sw to seal beam to ground. Complete circuit, R2 & R3 energize. If ckt brkr trips, then R3 is putting ground onto dk blue wire via closed contacts of R2, green wire to brown wire to R3 black wire.

Now, turn on h/lamp sw, power to connector on lt blue wire to R1 coil, thru coil and R1 energizes, R3 & R2 opens, no path for current flow, and power on dk blue for only for limit sw's.

I'd look for either R2 or R3 sockets wired wrong, they should work in unison, er, together, open & close at the same time.

Make sense? See ya tomorrow.

 

[paulm]

OK.....The problem with popping the breaker is too much current in R3 when it is "switched" allowing dark blue direct access to ground...dead short.

The solution to this is simply (Duh..:clonk not allowing R3 to "switch" when the light blue wire is energized. I can accomplish this by swapping the "switching" wires (two wire, light blue/brown connector) on R3. This way when the light blue wire is energized R3 is not "switched" therefore current runs through the dark blue wire, through the limit switches, through the motors, through the other limit switches, through the brown wire and finds ground via R3. This "slows down" the current flow via the resistors and such in the motors.

So, now the doors open with the key off and light switch on. I have a poorly functioning limit switch/weak motor on the pass side....oh well, I'll try and get that working better. Now to get the doors to close.......:thumbsup:

 

[Everett#2390]

What happened before the switching of the two wires?

 

[paulm]

What happened before the switching of the two wires?

Before, the light blue wire would get power and "switch" R3 allowing the dark blue wire direct access to ground....dead short and the breaker would pop.

All R3 does is provide ground access for the motors.

R1 switches to provide power to open the doors when the light blue wire (light switch is on, ignition off) is energized allowing current from orange wire to dark blue wire and the brown wire (operating circuit) to find ground, R2 & R3 do not change from wiring diagram.

When the ignition is on (light switch off), R1 does not change from wiring diagram, therefore current flows from orange wire to green wire. The brown wire (in the control circuit) is energized so R2 switches allowing current to flow from green wire to brown wire (operating circuit) and R3 switches allowing the dark blue wire access to ground. This reverses the current flow from above (ignition off, light switch on), so the motors spin the opposie direction closing the doors.


I haven't tested ignition on, light switch on....still have a problem with the pass side motor (too weak, won't trip the limit switch).

 

[Everett#2390]

Glad to read something is happening. i'm sure you are writing down all the changes you've done so you can get back to square 1 if you need to......

Where do the motors hook up in this schematic?
The limit switches are open/closed by the door?
Limit switches are shown closed because doors are in midtravel?

Maybe if the rest(?) of the circuit were shown, I could see a better picture.

 

[paulm]

If you look at the schematic, the motors are in the upper right and lower right part of the drawing. They are drawn as circles with two wires leading to them, one wire to each limit switch.

When you turn on the light switch, the light blue wire has power so R1 switches, R2 & R3 do not switch. Current flows from orange to dark blue, to the limit switches on the core support, through the motors, through the other limit switches and through the brown wire (operating circuit) to ground at R3....The doors open until they contact the limit switches, breaking the circuit.

With the light switch off and ignition on, the brown wire (control circuit) has power so R2 & R3 switch (R1 does not switch) and current flows from orange, to green, to brown (operating circuit via R2), to the limit switches, through the motors, through the limit switches on the core support, to the dark blue wire and finds ground via R3....The doors close until they contact the limit switches, breaking the circuit.


In the end I only had to make one change, which was to swap the "control circuit" wires on R3 so that when the light switch was on R3 was not switched allowing the dark blue wire direct access to ground.

 

[Everett#2390]

There you go!

 

[Everett#2390]

Maybe since you figured it out and got it to work, a professor here will look and give a grade for lab....LOL.

I give the effort an A- to get the doors to work from a tripping circuit breaker.

 

[paulm]

LOL, thanks!!

I'm still not out of the woods yet.....I just replaced the RH door motor and they do open when the light switch is on. A good start, now to make them close.

I just wish I could look at a schematic like that and figure it out. A schematic is a start for me, then I have to tinker to get my brain wrapped around it.

So, a relay question for you. In a relay on the control circuit, does current have to flow in one specific direction to make it switch? Can current flow either way (no diode limiting flow), but it only switches when current flows in one certain direction?



Reading a bit about relays, I found that the control circuit makes a magnetic field when current flows, therefore "pulling" the contact closed.....still didn't find anything about current direction.

 

[Everett#2390]

DC voltage coil polarization - no, at least on Bosch relays. But, depends upon relay design, will it be a polarized coil relay. AC voltage coils makes no difference.

Yes, current flowing through a coil creates a magnetic field about the coil core and pull in either an iron or steel, usually steel, lack of a better term, flap to the middle of the coil. Attached to the flap are contact(s), spring steel with carbon contacts, just the ignition point set, or brass, copper, gold, or silver, depending upon the design of the circuit. Some have one pole, some have two & three poles apiece.

 

[paulm]

I'm still confused then....looking at the schematic, the light blue wire and brown wire in the control circuit only have one ground source which is at R1?

 

[Everett#2390]

I'm still confused then....looking at the schematic, the light blue wire and brown wire in the control circuit only have one ground source which is at R1?

No, a path of lesser resistance is through the connector, tie point at h/lamp switch, through dimmer sw and through seal beam. H/lamp filament resistance is less than relay coil.

If you want close the doors, de-energize R1. Changes polarity of voltage to door motors. Brown wire positive to close doors, dk blue positive to open doors.