Author Topic: Which relay is which ?? (Read 15030 times)

Ben · « **on:** November 16, 2004, 03:35:30 »

Hi folks..........can someone tell me exactly how many relays a '64 Euro 230SL should have on the inner wing between firewall and battery ?

I have conflicting info and want to test some of these ?

Mainly I want to know what the silver one nearest the battery is, the one with the rubber grommets ?

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

George Davis · « **Reply #1 on:** November 16, 2004, 17:31:27 »

Ben,

I'm going to crawl out on a limb here and say the relay closest to the battery is the cold start relay, which on a 230 SL should switch both the CSV and the starting solendoid on the injection pump.

George Davis
'69 280 SL Euro manual

gugel · « **Reply #2 on:** November 17, 2004, 03:17:17 »

Ben,

George is right.

The 230SL has three relays on the inside of the left front fender. Using the names and numbers in the wiring diagram, the order from front to back (left to right in the photo) is

21. Relay for automatic starting aid, which controls (31) the electromagnetic starter valve (CSV) and (33) the magneto for mixture control on the injection pump. It closes when the starter is running and either the time switch (20) or the thermo time switch (32) is closed, as described below.

17. relay for wiper motor

20. time switch. Normally closed. It opens when the starter runs for more than a second. The thermo time switch (32) is closed when coolant temperature is below 35 degrees Centigrade, and it opens when the starter has been running for up to 17 seconds, depending on coolant temperature. It stays open when coolant temperature is above 35 degrees Centigrade, in which case only the time switch controls the relay for starting aids.

Download Attachment:

Relays230SL.JPG
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Chris Earnest

hands_aus · « **Reply #3 on:** November 17, 2004, 06:44:54 »

Chris,
I thought the time relay was an option.

Ben,
If it looks like the silver one in Chris' pic it probably will be for the wiper motor.
The relay for the CSV and CSS will be like the black one in the pic.
It should be a 4 pin 'make contact' relay.

My 250 has separate black 4 pin relays for the CSV and CSS plus the wiper relay and no time relay.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

J. Huber · « **Reply #4 on:** November 17, 2004, 11:43:07 »

Hey Ben.

A while back on Pag.113, John L. posted a helpful pic of the relays. I believe the order front to back is:
1. mixture relay (silver w/diagram on top)
2. lighting relay (black)
3. the wiper relay (silver)
and if you have it, the small black round time switch. That is the way mine looks.

James
63 230SL

gugel · « **Reply #5 on:** November 17, 2004, 13:13:02 »

For clarification: What James Huber (and on the other list, John Lieswyn) refer to as the "mixture relay" is number 21 in the Owner's Manual wiring diagram, where it is called the "relay for automatic starting aid". As shown, on my '65 German Euro 230SL stick it is black, with no diagram on top.

John's photo shows a "lighting relay", but my car has none, and none is shown in the wiring diagram. Perhaps it was added later, or only in certain countries.

Bob, the wiring diagrams in the Owner's Manual and in the BBB show a time switch (20), and there is no indication that it was an option. Its function is to indirectly (via the relay for automatic starting aid) open the CSV and the mixture solenoid on the injection pump for one second when the ignition switch is turned to the "start" position, regardless of how warm the coolant is. Perhaps that function was later incorporated into the thermo-time switch?

Chris Earnest

A Dalton · « **Reply #6 on:** November 17, 2004, 14:08:19 »

The 230 had the 1 sec time sw. The 250 did not , as they added another 4 prong relay so the rack mixture solinoid on the pump would aid start without the CSV coming on above 35C.. That is why Bob has two 4 prong relays... This system did not work as well as the 2 wire, 1 sec time sw. , so they came out with a mod kit to add this feature back so the car got a 1 sec squirt even when warm.. It supposedly helped on the No Start condition these were prone to after a hot run and 10/20 min turn off..
Which is why many put a CSV pus button in the cabin......
The later pump eliminated the rack solinoid as they claimed it not needed after the 1 sec feature..

hands_aus · « **Reply #7 on:** November 18, 2004, 06:37:15 »

thanks Arthur,

The second relay for the CSS works each time the starter is used.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

A Dalton · « **Reply #8 on:** November 18, 2004, 09:43:12 »

quote:
Originally posted by hands_aus

thanks Arthur,

The second relay for the CSS works each time the starter is used.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

BB
You are welcome..

Yes, the reason for the extra relay was so that the rack would be enrichened , no matter what temp the coolant was ..they needed it to isolate the 2 ciruits [ CSS/CSV ]
as you say.. every time the starter circuit is energized.
they eliminated this feature , stateing not needed .. but I liked it .. it was prob a cost effective change and the return to the 1 sec squirter..
Being a Tech, I have the cabin over-ride on every Benz I have ever owned [ with the exception of my EFI E320], so I am the sensor...
Electric Manual Choke , I call it...

gugel · « **Reply #9 on:** November 18, 2004, 15:51:22 »

Arthur,

quote:
The 230 had the 1 sec time sw. The 250 did not , as they added another 4 prong relay so the rack mixture solinoid on the pump would aid start without the CSV coming on above 35C.. That is why Bob has two 4 prong relays... This system did not work as well as the 2 wire, 1 sec time sw. , so they came out with a mod kit to add this feature back so the car got a 1 sec squirt even when warm..

Just want to make sure I understand your post correctly. It sounds like you're saying the best setup was in the 230SL, where both the CSS and CSV are always synchronized, and both are activated for 1-17 seconds while cranking, depending on the coolant temperature. Or is there some advantage to the CSS and CSV being independent of each other?

Chris

A Dalton · « **Reply #10 on:** November 18, 2004, 23:51:42 »

Chris,
As far as starting is concerned, the most effective device is the squirter [ CSV]..

The start with both CSV and CSS is the same with both single and dual relays when the temp is under 35C.
The only feature the dual relay design changed was for CSS without CSV above 35C .
Single relay did not allow for this above 35C. But , they made up for it with the 1 sec CSV time relay. This relay energized both CSS and CSV for the 1 sec , but the important part here was the squirter..

Does CSS at any temp make for a better start system -I think not..
Does the 1 sec squirter at warm temps make for a better start ?
I think so..probably quicker..
The problems with both ??..
Squirter at some high temps can actually hamper a start due to too rich a mix at intake for ambient conditions..kinda like using your old manual choke on a hot day in the summer ...
Problem with just a CSS when warm ? .. slow starts under some conditions and just not as effective as a squirter. A plus on CSS is that it is adjustable at the solinoid/rack and can be tuned richer/leaner..
The early pumps [ oil res.] would not hold injector line pressures well , so the CSS would help overcome this by allowing the lines to recover faster by havng the rack in a rich position. But , once they replaced the cone check valves with ball valves , this was no longer a problem... so, many believe this was the one of the resons for the CSS being eliminated ..
I think the CSS system would be a better system if one had the new style ball checks and it was set for your own engine, but it seems that the 1 sec squirter works best for rapid start and once started , the IP takes over anyway...I think that Benz did this design change in order to get rid of the 1 sec , warm squirt, but it just did not work as well as the older system .. again, hard to compete with a squirter for start..even on your chain saw/lawn mower..:}
My personal set-ups are 2 relay , independent CSV/CSS with a cabin switch for CSV of my chosing above 35C...
Benz never did get these systems to work real well , so that is why the 1 sec CSV modification was recommended forthe later with start problems... but I think it was just a way out for them having tried four different versions .. none of which were great ..
Also, some very early 230s had the dual relays with a 5C thermo time sw . These can be modified to the later 230 with a wire change and a 35C time sw ...

Ben · « **Reply #11 on:** November 19, 2004, 03:41:54 »

Thanks guys for all your inputs and explainations !

My car is exactly as Chris's photo and works as he describes. I have since opened all the relays and ensured they work, I had to repair and re-solder the CSV/CSS relay as it had come apart.

I verified its operation and also verified the operation of the time relay, the CSS and checked the operation of the CSV solenoid by hot wiring it to the battery.

The thing is the car still wont start !

It is actually worse now since I messed with it, and this morning it took roughly 2 minutes of intermittant cranking to start !!

Yesterday I hot wired the CSV and it jumped to life !

I figure I have a wiring problem somewehere !

Just to verify.........if the Thermo Time Switch were bad would this effect my cold start ? I dont think so but........just to check...what the test method ?

I have searched and read both sites but I'm not sure which terminal to "Ground" and at what point ??

I suppose if I get a "live" at the CSV when cold cranking then everything is ok ! I did check this in the first place but had so many poor connections etc since then that I should verify it again !

Can the CSV nozzle be cleared if blocked ?

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

J. Huber · « **Reply #12 on:** November 19, 2004, 10:06:59 »

Hi Ben. I am under the firm belief that the TTS (ThermoTime Switch)is very critical to cold starting. Unfortunately, I don't really have the ability to explain it very well. I hope George or others can back me up.

Good luck.

James
63 230SL

George Davis · « **Reply #13 on:** November 19, 2004, 10:16:01 »

Ben,

as James said, it could very well be the thermo-time switch (TTS). If it has failed, neither the CSV nor CSS will work (except for 1 second if the 1 sec relay is working).

With engine dead cold, connect a volt meter or test light to the wire terminal on the CSV and ground. Then locate terminal G on the TTS and disconnect the wire from it. Insulate the end of the wire so it can't short to ground. (This disables the TTS internal heating element). Disable the ignition (remove dist. cap or pull the coil wire). Then crank for 6-7 seconds. If all is well, you should get voltage at the CSV for the entire time you crank.

Assuming you have the 1 second relay and it works, you may see voltage for only about 1 second. Or you may get no voltage at all. In either case, there is something wrong with wiring, the TTS or the relay(s).

Now connect a wire from terminal W on the TTS to a good ground. Then crank again. If you get voltage at the CSV for the entire time you crank now, your TTS is bad.

As Arthur has mentioned, one way to give yourself control over the CSV is to wire a manual switch in the cockpit. I did that by running a wire from terminal W on the TTS to a momentary switch to ground; this overrides the TTS and causes voltage to be applied to the CSV whenever the switch is closed and the engine is being cranked. It's also a quick fix for a bad TTS while you await delivery of a new one.

Good luck!

George Davis
'69 280 SL Euro manual

A Dalton · « **Reply #14 on:** November 19, 2004, 12:05:05 »

<<As Arthur has mentioned, one way to give yourself control over the CSV is to wire a manual switch in the cockpit. I did that by running a wire from terminal W on the TTS to a momentary switch to ground; this overrides the TTS and causes voltage to be applied to the CSV whenever the switch is closed and the engine is being cranked. It's also a quick fix for a bad TTS while you await delivery of a new one.>>

To add to Georges post .

This 'W" terminal the TTS is the ideal spot to tap into the system for a cabin sw . By going there vs. the CSV itself, you are still using the original relay contacts, so the cabin sw only needs one wire to the momentary push sw. and then ground the sw in the cabin.
You are simple grounding the relay , just like the TSS does...so, you can still have the TSS circuit operate as intended , but you can
have the added feature of CSV after the TTS has dropped out due to temp above 35C.. Best of both worlds..

The 1 sec relay mod attemps to do this same principle, but it is restricted in the sense that it is a timed event and sometimes is not long enough and other times not needed at all.. but. it is automatic.
...As I say, do you like an automatic choke or a manual one???

hands_aus · « **Reply #15 on:** November 21, 2004, 06:58:58 »

Like Arthur I have installed a bypass switch.
It picks up 12V at the interior light and runs through the push button switch to the terminal on the CSV.
It works a treat.
My cold start system works great when the engine is cold but if hot and after sitting a while, I sometimes need to push the switch.
Often just pushing the accelerator pedal halfway to the floor is enough.

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

Ben · « **Reply #16 on:** November 22, 2004, 03:28:55 »

Over the last week or so I have searched both sites and some archives for anything to do with the TTS or CSV. I feel I could write a book on the subject now !

Thanks to everyones input I have eventually cured the problem and the car jumped to life this morning, having been left outdoors at 4degrees overnight, with no delay whatsoever !

I believe I have had numerous issues and faults with the system since I got the car, or shortly after. I have it over 3 years and it used to be pretty good at cold starts but bad at hots starts. I tweaked the usual settings and this resulted in decent hot starts and fairly decent cold starts, the latter has deteriorated over the last few months to the point where it was touch and go whether it would start before the battery drained.

So having physically removed and cleaned a gummed up CSV and hot wired it directly to the battery I discovered it WOULD squirt, but not with the key turned ! I earthed the TTS and still nothing. I removed the relay and opened it to discover a broken connection inside. I repaired this but still nothing. I discovered a bad connection in the block connector, still nothing. So with the aid of a multi meter I checked and ruled out the TTS and the wiring and eventually dicovered that even though the relay was pulling the contacts in they still werent latching together. So with some filing of the points and a little bending of the posts I got it to work and HEY PRESTO the car fires right up !

I am delighted as the weather has really turned cold here but I still like to use the car all the time and now I can !!

So thanks to everyone who has posted on this subject both here and now and over the years !

Regards,
Ben in Ireland.
'64 230SL 4sp.

Ben · « **Reply #17 on:** November 26, 2004, 04:25:24 »

Okay so now my cold starts are perfect but my hot start is non-existant !

After refuelling or similar very short stops it simply will not restart ! If I leave it for 15 minutes i have no problem !

If I remove the fuse for the CSV it fires instantly, so it would appear that the CSV is squirting even when very hot, or for too long when hot and flooding it !

Does this mean the "hot" side of my TTS has failed ??

Having trawled through the other posts I still am not sure how to test this !

Anyone ??

Regards,
Ben in Ireland.
'64 230SL 4sp.

A Dalton · « **Reply #18 on:** November 26, 2004, 10:38:55 »

There are two relays for the CSV on your chassis..

One is the TTS relay [ four prong] and the other is the 1 sec relay. [2 prong]
In order to check each , do these simple test in the order specified.
When coolant is above 35C, disconnect the "W" wire on TTS
This eliminates the TTS crcuit.
Now, with a 12v test lamp on the CSV, crank the engine .. you should have 12v for approx 1 sec. [ this circuit is regardless of temp] If it is Longer than 1 sec, the relay is bad and you are flooding the warm/hot engine.
If this checks out OK, diconnect the single wire [term #85] from the 1 sec relay and hook the W wire back up on the TTS. With TTS wired , you should have 12v at CSV when cramking, but ONLY below 35C... if above 35C , you have a bad TTS [ or shorted wire to ground]
The reason for checking these two circuits individually is b/c they are wired in parallel and by unhooking each for the tests will let you know which one is the faulty one . When they are both hooked up, you can not tell which is causing the 12v at CVS. So, we just seperate them for testing..

As you have no problem once you remove power [ fuse] from CVS, I suspect the 1 sec relay is holding in too long..
This test will pin point that condition..However , the TTS test also
has to be made , as an internally grounded TTS will cause the same condition [ ie.-CVS activation above 35C for entire crank time ..]

It is common to have a vapor lock/heat soak condition after short engine turn off in high ambient temps.. this is what the 1 sec relay is supposed to aid ..which is the condition you are having...
Another famous vapor lock spot on these is at the fuel filter canister [it grabs heat from the motor mount ].. If this is suspect , the remedy/test is to run fuel pump for about 15 secs [ key on] to make fuel flow before attempting a start...don't confuse this with CSV problems .. just another condition to mention for et al...

Mike Hughes · « **Reply #19 on:** November 26, 2004, 17:12:25 »

I would certainly make sure that both of the relays are working properly, too. I recall reading in Mercedes Collector #6 that an improved ball check valve was developed for the 280SL to help prevent vapor lock in the individual injector lines from the IP. The suggestion was that replacing all six valves with the newer design on the 230/250SL would also improve hot starting on these earlier cars.

- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)

Ben · « **Reply #20 on:** November 29, 2004, 06:14:47 »

Thats excellent info Arthur........just what I need !

I did open the 1 sec relay and I verified it moved visually......but that may not be enough, as I didn't actually test the circuit at the same time or time it anywhere !

Mike....I presume these are the valves at the injector lines on the pump ?

Regards,
Ben in Ireland.
'64 230SL 4sp.

Mike Hughes · « **Reply #21 on:** November 30, 2004, 14:30:08 »

quote:
Originally posted by Ben

Mike....I presume these are the valves at the injector lines on the pump ?

Yes. Supposedly they are much more effective at keeping the lines between the IP and the injectors "at pressure," which also prevents fuel from leaking back into the pump and, from there, contaminating and diluting the IP oil (or even the engine oil on later models).

- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)

A Dalton · « **Reply #22 on:** November 30, 2004, 15:26:02 »

To add to Mikes info.
The ball checks replaced the Cone style checks after pump 18Y
[ late .043/ res. oil pump]
So, late 250sl oil res pumps can have the new checks, but all .044 already have them.. along w/crank lube system.
The valves were not to solve hot start problems , but rather poor starts/run after a delayed time frame [ usually overnight].. you will notice your car seems to run on just a few cylinders at warm up first
10/20 secs... this is an indicator of leaking cone checks..and VERY common.
The Hot start problems were remedied with the addition of [ again] a mod kit that included a 1 sec CSV relay that was wired for CSV regardless of temp.,.. Crank only..
After the ball valves were added to 18Y and on pumps. the rack start solinoid was eliminated .. [ which I kinda liked]
The Ball valve replacement is part# 000-074-17-15

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Author Topic: Which relay is which ?? (Read 15030 times)

Ben

George Davis

A Dalton

A Dalton

A Dalton

Ben

George Davis

A Dalton

Ben

Ben

A Dalton

Ben

A Dalton