Diagram: Thermo Time Switch, 4 Pole Relay, Cold Start Valve, Ignition

[rbouch8828]

Does anyone recaLL where I can find the hand-drawn sketch of a wiring diagram showing the connections for the CSV, TTS, 4PR and the Ignition (I think that was the 12 V source) that I saw a while ago, and I have been trying to find it with no luck.

I want to copy it for my file and want to print it out. I need to make up a harness of these wires for my Aug of '69 280SL

Many thanks,

Roland

[lpeterssen]

Dear Roland

The easiest way to bypass the TTS, during cranking is to bring a negative signal to the two relays that control the CSV and the Fuel enrichment selenoid at the injection pump.

Just run a wire on your dashboard to a ground source, and the other end of the switch (output) should be run to the port 85 on both relays that control the operation of CSV and Fuel Enrichment selenoid at the Injection pump.

Best regards
L.Peterssen

[rbouch8828]

Thanks for the reply, but I’m not trying to bypass the Thermo Time Switch during cranking per se. I am trying to replace the existing wiring which is failing. I am currently getting only 5 volts at the CSV instead of 12 volts, so it’s feed wire is acting like a resistor not a wire.

Someone posted a hand drawn diagram of the wiring for just these components a while ago, and it is exactly what I am looking for, so I can make up a small harness to replace the failing wires I have.
Best,
Roland

[lpeterssen]

Your car is automatic? Or manual? The easiest is the automatic to rewire….

[lpeterssen]

Here your diagram

Just made

Best regards
L.peterssen

[rbouch8828]

Manual,

Thanks very much for the quick diagram!

Kind regards,
Roland

[rbouch8828]

After printing out your diagram and taking it to my garage, I found a printed copy of the other diagram that I had been searching for, so I took a picture of it and thought I would upload it for you to see what it was.

[lpeterssen]

Dear Roland

Someone have been modifying your wiring harness. If everything is connected like you indicated on your hand made diagram, it is WRONG.

1.  4th relay.   What I understand from your drawing  is this.

1.1. Whenever the TTS gives its (-) negative output signal connected to port 85 on this relay, this relay brings a positive stronger signal to the ignition coil (+) terminal while the car is cranking (after ballast resistor).  This is wrong since the stronger positive signal comes after the main fuse box, fuse no.6.   That does not go that way. 

1.2. Right way to bring a stronger positive signal to ignition coil while cranking the car is to use the port labeled T16 on the starter.  You should run one cable between starter selenoid port T16 to the ignition coil (+) port just after the external coil resistance. (Ballast resistance)

2. CSV relay.  On your drawing I understand that the CSV RELAY is controlling the CSV.  That is correct. But…, who is controlling the INJECTION PUMP FUEL ENRICHMENT SELENOID?  That is not reflected on your drawing.

Best regards
Lp

[rbouch8828]

That wasn't a drawing of my car. That was a drawing that I found on the Forum about the topic of the starting situation and I just printed it out from the Forum. I do not know who made the drawing, but I was trying to find out where I had found it in the Forum so I could see what the details were.

Here is the part of the Mercedes drawing that does relate to my car and what I am trying to re-wire:

[lpeterssen]

Perfect this drawing is correct.

[rbouch8828]

I am trying to purchase replacement wire for these wires and have found a business that is local to me that carry’s many different auto wire colors and gauges.

Do you know the gauges of these wires? I found the colors on their website and they have them but on the pink and blue, they only have 18 gauge in plastic. They may have it in cloth covering in larger gauges.

Do you use the cloth covered wire, or only the plastic?
Best,
Roland

[lpeterssen]

Dear Roland

As many people have difficulties understanding a wiring diagram, I am not sure if it is your case I will explain in words how this should be wired.

Materials:

A. Brown cable for grounds
B. Violet or pink able for all T50 (cranking signals)
C. Black cable AWG 14 for (+) signals that are switched with the relays
D. Blue cable AWG 18 for (-) signals
E. 2x original Mercedes 4 prong relays, or modern style Mercedes’ silver cubed relays with 5 prong.

Solution
=====

1. Bring 2x new cables BLACK (awg14 thick) from output side fuse no.6 at the main fuse box to the LEFT FENDER where are the relays that control the CSV and FIP enrichment selenoid.
1.1. Connect this large BLACK cables to port labeled 30 on each relay .  This is the strong (+) signal that you want to control,  therefore it should be connected on port 30.

2. Label the relays.   One should read CSV, and the other should read FIP.  The CSV relay will control the strong signal that goes to the CSV at the Intake manifold.   The FIP relay will control the strong signal that should go to the Fuel Injection Pump SELENOID.

3. T50 signal.  T50 signal is a (+) signal that comes out of your ignition tumbler switch each time you crank the engine.  It comes from port labeled “50” at the Ignition Tumbler.  The cable is usually VIOLET or GRAY depending on the year of manufacture of your car.  Old w113, specially the 230SL have a GRAY THICK cable for that service, in recent PAGODAS The T50cable is VIOLET.  IF your car has MANUAL TRANSMISSION the best place to take the T50 signal for controlling these relays we are talking about is the IGNITION TUMBLER SWITCH.  If your car is automatic you can save some time taking that signal at the engine compartment firewall where the Parking/Neutral/Reverse switch is.

3.1 take two thin Cables (awg18) in VIOLET from T50 terminal at the IGNITION TUMBLER SWITH or PARKING/NEUTRAL/REVERSE switch at the engine compartment firewall.  Bring these cables to the following CLIENTS.  One client will be the FIP RELAY, the one that controls the Fuel Enrichment Selenoid at the Injection pump.  CONNECT one violet Cable to port labeled “86” at the FIP RELAY.  The other VIOLET cable should be directed to the CLIENT = TTS. THERMO time switch (TTS) which is on the engine front side where the water temperature is measured.   VIOLET cable to port labeled “G” a the TTS.

4. TTS ANSWER to the CSV RELAY.  The TTS produces a (-) signal whenever the water temperature is below 35 degrees Celsius and the engine is cranked at the same time.   Run a BLUE thin cable between TTS port labeled “W” to the CSV Relay port “85”

5. Jumper cable between relays.   Run one VIOLET thin cable between the two relays.   Connect one end to port “86” at the CSV relay and the other end to exactly the same port “86” on FIP RLY.  NOTICE that FIP RLY had already one VIOLET CABLE connected in that same port “86”

6. CSV RLY OUTPUT.  We already said that CSV RLY had one thick BLACK cable connected on port “30” that came from fuse 6.  Now we need to connect the OUTPUT of the relay which comes from port “87”.  So Run a thick BLACK cable again from that port “87” to the CSV ITSELF at the manifold intake.  With this step the CSV IS ready to work properly.

7. FIP RLY OUTPUT.  Run one thick BLACK cable from port “87” of this relay to the FIP SELENOID ITSELF.  with this step also the FIP selenoid is properly connected.
7.1. Connect a thin BROWN CABLE between port “85” at the FIP RLY and the chassis ground.

You got it, the system is correct now.

Any questions are welcomed to www.wiredoktor.com

Best regards
L.peterssen

[lpeterssen]

I am trying to purchase replacement wire for these wires and have found a business that is local to me that carry’s many different auto wire colors and gauges.

Do you know the gauges of these wires? I found the colors on their website and they have them but on the pink and blue, they only have 18 gauge in plastic. They may have it in cloth covering in larger gauges.

Do you use the cloth covered wire, or only the plastic?
Best,
Roland

Dear Roland

I use in my projects only MARINE GRADE FULL COPPER cables with high temp/oil resistant  PVC jackets. 

NO CLOTH jacket cables.

For simplicity if you do not mind changing a bit the original Colour scheme used on your car wiring I would suggest the following colours.  The cable gauges are exactly as Mercedes originally used.

1.  BLACK in AWG14 for the strong (+) signals that you want to control for those CSV and FIP enrichment selenoid RELAYS.
2.  VIOLET  in AWG16 or AWG18 for the (+) triggering signals coming from the T50 terminal at Ignition tumbler switch
3.  BROWN in AWG16 or AWG18 for some ground connections for the FIP RLY (small quantity)
4.  BLUE in AWG16 or AWG18 for the (-) signal coming out from TTS TO the CSV RLY port 85

With that simple scheme you will understand what are you controlling.

Best regards
L.peterssen

[rbouch8828]

Thank you very much.

One color that is different on my car, as I remember it from working on it, is that the Thermo Time Switch has Pink and Blue wires. I can’t remember seeing any Violet wires on those parts when I was working on them.

I will take another look the next time I am with the car to check.

Thank you again.
Best,
Roland

[lpeterssen]

Yes that is correct the cables at the TTS are one is ROSE and the other is ROSE/Blue

But…..  for simplicity and so that you understand that signal is each cable carrying is that I am
Suggesting the change. 

The ROSE cable at the TTS Is carrying the same T50 signal that comes from the Ignition tumbler.  As T50 cable at ignition tumbler is VIOLET that’s why I suggest to buy VIOLET cable.  So you understand just by watching  it is a T50 signal. 

On the other hand output cable from
TTS is ROSE/BLUE.  Therefore as its hard to find ROSE/Blue cable I suggest BLUE instead

Best regards
Lp

[rbouch8828]

They have the rose/blue combination (they call it Pink) in 18 gauge. The rose alone is available in all gauges down to 10.

[lpeterssen]

Excellent. Give me the email
And contact data to buy some

[rbouch8828]

Here is a link to their website. Look at the left side and go to the bottom of the list and select that item. It will take you to a series of pages that has all the different types of wire they carry.

The plastic covered wire comes after the cloth covered wire, so you have to go a fair distance down the page to get to the plastic wire. Then it is listed by gauge.

http://www.riwire.com/

[rbouch8828]

I just took a look at some of the visible wires and one that was not visible, so I cut back the covering to reveal what the wire was and was surprised. That was on the Cold Start Solenoid (Valve) Feed Wire. It is a heavy gauge wire, perhaps 12 or so and it is black and white.

[lpeterssen]

The Colour of that cable is right. black/white/rose

[rbouch8828]

There is no rose on that one that I can find. I can only find black and white.

[lpeterssen]

Dear Roland

Do not worry about that, cables age, and some color stripes fade.

I would suggest to ground that CSV.  There are two screws that fix the cold start valve to the intake manifold, make a ground lace from one of those two screws to the chassis.  Sometimes the low voltage reading you mention at the intake manifold CSV could be caused by improper grounding of the engine itself.

The engine should have a large grounding strip at the transmission case to the firewall.  If that ground has dirty contacts the ground provided to the engine is not enough to properly work many electric accesories.

Also it seems t me that your 8ntake manifold is too silver like it has been painted during a restoring procedure.  That homogeneous silver Colour could not be the bare aluminium.  Paints reduce the conductivity, and it might be another culprit on this electrical multi factorial equation.

So nevertheless on the original car design there was no ground strip directly to the base of the CSV is not a bad idea to have it now that your car is more than 50 years and has tons of makeup (paint) over its body to hide its imperfections.

Best regards
L.peterssen

[rbouch8828]

I did the restoration myself. I did not do any painting of the CSV. I just cleaned and polished it. When I removed the engine, I obtained a new grounding strap (copper braid) and cleaned the attachment point and then attached the replacement.

By the way, although I am not an engineer, I did design and build some recording studios and I did transmitter maintenance on radio and television transmitters as well as studio equipment. So, I am pretty familiar with electronics and circuit diagrams.

[lpeterssen]

Dear Roland

In that case everything is clear then.  With your background you can easily solve this electric puzzle.

Will recommend to buy a CONDUCTIVE CARBON GREASE in amazon or somewhere else to put some of this stuff on all ground post after trough full cleaning of the contact surfaces

Best regards
Lp

[rbouch8828]

My belief is that the old wiring in some places is acting as a resistor and not passing the full voltage through as it should be. I believe that is why I am getting 5 volts at the CSV and not 12 volts as I should be. So that was why I decided to rewire that circuit and I thought that while I was at it, I should rewire the other parts of the circuit too: the TTS and the 4 PR. As you have mentioned the line to the ignition switch as well.
So I have been trying to find out what the correct colors are for these wires. Here my experience does absolutely nothing to help me. I have no resource for finding the wire colors that I am aware of, other than peeling back the coverings in the engine bay. As you have said some colors may have faded, while others are hidden.
I am trying to make a master list of the wire colors and their gauges so I can order the ones I need for this particular circuit.
Best,
Roland