Chasing a Short (I think) in Fuse #5

[Jordan]

OK, got the cover off with some robust wiggling.  It is an 11 pin connection.  I used an ohm meter (one wire on ground) and took a reading from each of the 11 pins.  Picture below shows what I got.  Two of the pins did not give a reading and two gave higher readings (22 and 34 ohms).  Don't know if there are wires connected to the two pins that didn't give a reading.  Does anyone know what each pin is for?

Unfortunately I could not start the car as the fuel pump is no doubt running through this connector as I couldn't hear it whine when I turned the ignition key.

[66andBlue]

Thanks very much.  I found it on mine, mounted to the side wall, not on the firewall as it appears to be on Alfred's earlier 230SL.  Tried pulling on the cover and doesn't seem to want to move.  It does pull apart correct?
I also found this switch tucked under the dash.  Anyone know what it is for?  It pulls out and pushes in.  Seems to be an integral part of the wiring.  Does it get mounted somewhere?  Thanks.  Hope to see what I can find today.

Hi Marcus,
could that be an added switch for an emergency flasher? Nothing happens when you pull??

[Jordan]

Alfred, my car does not have the emergency switch as shown in your picture (there is nothing there at that location).  I have everything unplugged at the moment so can't check if it is an emergency switch.  It was certainly not added after the fact since the wiring ties right into the wiring harness.

Update, yes Alfred it is the 4 way emergency flasher switch.  Didn't even know I had one so one good outcome so far.  Does this get mounted somewhere or is it just suppose to tuck under the dash?

Would love to hear from the electrical gurus on my ohm readings and what they signify.

[66andBlue]

..Does this get mounted somewhere or is it just suppose to tuck under the dash?
Would love to hear from the electrical gurus on my ohm readings and what they signify.

Marcus, the emergency flasher should be mounted as shown in the photo of my 1966 230SL - same year as yours!.
If you don't have a hole in the dash then you need to search for location measurements. I recall that they were posted here but forgot by whom.
It might be difficult for you to do but can you identify the wire colors for each point in your drawing?
That will help identifying the circuits.

[Jordan]

Thanks Alfred.  Is it a definite that the flasher was mounted on the dash as in your picture?  My car is a late (Oct) Euro '66.  Would it have been different for the US market maybe? The knob is also different, but maybe that is an after market knob?

I'll take apart the connector to see which wires go where.  Do the higher resistance or no reading pins mean anything?  Those that gave a reading don't seem high so am assuming they are OK.  Maybe the no reading pins, but I will see which wires go to those. 

[Jordan]

Alfred, I just looked it up and an emergency flasher was added to US only cars on Aug 9, 1965, starting at chassis # 12497.  Don't know when they were added to Euro cars or if they were ever mounted on the dash.  Was yours a US car?

Labels for the emergency flasher, such as seen in your picture, didn't start until chassis 13324, 22 Sept, 1965.

[ja17]

Jordan, check to see if your fuse blows with the plug disconnected.

[Jordan]

Joe, do you mean crank it over (pump isn't running) or just turn the ignition to just before engaging the starter?  I turned the ignition to the point where I would hear the fuel pump and then turned it off.  Fuse did not blow.

Below is a photo of the wire connector in the car and then which wires go to which terminal.  None of them appear loose as I am able to pull each pin out and wire is well connected.

[Jordan]

Joe, I engaged the starter (wouldn't start obviously) and the fuse did not blow.  So I assume the short is therefore somewhere in the rear wiring harness?

[66andBlue]

Marcus,
I could identify most of the wires but not all; see attachment.
If you go to the color wiring diagram: http://www.sl113.org/wiki/Restricted/ColorWiringDiagrams
you'll see the connector #46 - use the legend for the diagram here:
http://www.sl113.org/wiki/Electrical/WiringDiagram
that should help you tracing the wires further. My hunch is that you were copying the connector side (female?) that goes to the front.
I don't understand why you have an open slot though, #46 shows 12 slots. Do you have a trunk light?

[Jordan]

Thanks Alfred, I missed that connector on the wiring diagram.  I'll have another look at it. 

I was using the mail side of the connector and do have a trunk light.  I notice the trunk side has 12 wires on the wiring diagram, which is what I have, just two of the wires are sharing the same post (#1).   The grey/blue wire on post 1 is the trunk light.  What is a clearance light?

Do any of my resistance readings seem odd?  Not sure why I am not getting a reading from 2 of them.

[ja17]

Next plug the main connector back in.  Now unplug every plug in the trunk, tail lights trunk light sending unit for fuel, back up lights etc. and see if the fuse blows now.

[Jordan]

Thanks Joe, I will try that tomorrow.

Alfred, I filled in the gaps in the sheet.  I do have 12 wires, just that 2 of them are on the same post.

[66andBlue]

Marcus,
the fact that you have 12 wires and only two doubled up is even more strange.
Take a look at the wiring diagram that Achim created - most likely for a Euro version 1966 230SL, but we need to ask him.
You should have 14 wires on the left part of the handshake connector and 12 wires on the other side. If the wiring diagram is correct then that should be the rear part of the harness but you should check that.  All 12 slots (or holes) should be filled in both halves of the handshake connector according to the diagram.
To me and my very limited knowledge of electricals it makes little sense that the trunk light and the tail light (left or right?) are doubled up as you indicate!? 
Also this wiring diagram does not tell us how the later additional emergency flasher was wired in. Lets hope someone has an answer to this.
BTW, my numbering does not coincide with your numbering of the slots/holes; I just went down the schematic.

I have an interest in this since I am also chasing a wiring problem in my 1964 230SL.

[Paul & Dolly]

Hi Alfred,& Jordan

Some of the cars were wired so that the trunk light only operated whenthe tail lights were on ,and the trunk open, so that would explain tthe situation here maybe.

>>To me and my very limited knowledge of electricals it makes little sense that the trunk light and the tail light (left or right?) are doubled up as you indicate!?  <<

Have fun

Paul

[Jordan]

So I believe I have narrowed it down.  Reconnected the rear harness, started the car and the fuse did NOT blow. Fuel gauge working, backed up the car, still working, left turn signal, still working, right turn signal I heard the snap as the fuse blew.  I have lots of fuses so did it again with the rear lights and signal lights disconnected and again it blew when I used the right indicator. 

So would the short be in the indicator stalk or the wiring to the rear right indicator light?

BTW, trunk light only comes on if the headlights are on.

[Pinder]

disconnect the steering column switch from harness and see if you can trigger right turn signal by jumping pins as described  in the following link. this will narrow down issue in stalk or harness.

http://www.sl113.org/wiki/Electrical/SteeringColumnSwitch

[Jordan]

So I disconnected the steering column switch from the harness and my wiring looks similar to the one seen in the link.  I notice that my hazard lights have also been wired in here, to pins 9 and 10.  Not sure what you mean by jumping pins Pinder.  Do I just attach a wire from pin 3 to 9 (right turn signal)?  Then what?  If I then have to test resistance do I just touch pins 3 or 9?  Told you I was electrically challenged.  Thanks.

[Pinder]

i could be wrong but jumping the pins is what the indicator switch does and in theory your turn signal light should flash just like if you used the turn signal switch.  if it blows a fuse then that means its not your turn signal switch that has a problem.

[Pinder]

Yes jumping the mins means attaching a wire from one to the other. it completes the circuit from the power to the indicator and the indicator flasher. it should make your turn signal flash. what you are simulating is operating it via the turn signal switch. if it works and no fues blow then the problem is in the wiring from the turn signal switch connector to somrewhere up to the signal stalk or maybe inside the switch. hopefully its just in the wiring and you can fix it with no cost.

[66andBlue]

..... left turn signal, still working, right turn signal I heard the snap as the fuse blew.  I have lots of fuses so did it again with the rear lights and signal lights disconnected and again it blew when I used the right indicator.  ......

Marcus,
I bet it is the column switch. You wrote that the emergency flasher is wired to pins 9 & 10 and it works without blowing a fuse. Thus I think that your forward wiring is OK, but the right turn signal switch is not. Take a look at my photo with the emergency push/pull switch; you can see the part of the switch housing. Pull yours out and inspect it (with the battery disconnected or the handshake connector separated!!) perhaps you can see the culprit, a metal chip or dislodged spring.
Test the resistance between the wire for the right turn (black/green?) and the housing. It should be very high (no short) and drop to zero when you move the lever up.
I believe a have an old 230SL column switch and if I can find it I'll shoot some photos.

[Jordan]

Pinder, even if I connect pins 3 and 9 how would the indicator work as it is not hooked up to the wiring harness.  Or am I connecting the female ends of pins 3 and 9?

Alfred, I removed the switch housing and I am not seeing anything loose or anything that might be out of place.  Springs are all good, although my right indicator often does not stay in place.  It will often automatically jump back.  Everything is so well packed into the switch I could not identify which was the black/green wire.  I did recheck the emergency lights and all four corners flash when I engage the emergency switch without blowing the fuse.  Picture quality isn't the best but hopefully you can see the various sides of the switch housing.

[66andBlue]

Marcus,
here are photos of my defunct 230SL column switch. The normal wiring comes in from the back where I have attached the alligator clips for testing. There are three soldering posts for the turn signal wires. The top row shows the switch in the normal position (stalk is straight) on the left and the Ohm meter shows a "1" meaning more than 200 Ohms (note setting). Pushing the switch to the side (which I believe should be the up or right turn position) opens the connection and the resistance goes to 4 Ohm.
The lower row is the opposite.
The actual switch is under these three soldering posts; also see your photo that I modified.
If you follow those wires to the end connector you should be able to test the switch as I did.

[Jordan]

Alfred, thanks, I was able to identify the correct wires (I marked them below).  Unfortunately or maybe fortunately I got 200+ ohms with the stock straight and just over 1 ohm when I flipped the switch, both left and right.  The reading would start at around 3 and drop down to just greater than 1 over about 10 seconds.  So that would signify the column switch is OK and the short is elsewhere?

 

[ja17]

Try disconnecting the main rear harness again and activate the turn signal combination switch. If the fuse does not blow, then it must be in the rear harness or rear devices.