Ballast ign mod.

[A Dalton]

Although there were many 113 version starting aid changes made to the fuel system,[CSV circuits] the ignition did not get design changes  until the late models.
  On standard ign., a ballast shunt is a good mod. This can bedone if one changes to the later 3 terminal sol. starter and incorporate a 12v feed off the solinoid to feed direct 12v to ign during crank/start , thereby shunting the ballast.
 The problem this solved was the ign suffers from low voltage conditions during crank due to high load starter draw .
 So, for those with the earlier chassis [230/250] who wish to remedy/modify this with a more simplistic approach than starter/sol. change-out, here is an isolation relay circuit that will do just that and even those that shy from electical workings should have no trouble in doing.
 It is a  SPST 12v/30A relay that uses existing circuity and can be hidden or just mounted close to the ballast resistor.
 I recommend a RS relay as it has it's own mounting tab and uses spade connectors, making the install easy. It is also economical at approx $5..
 The load contacts of the relay simple shunt the ballast , allowing battery voltage to fire the ign during crank only. This usually results to be approx 10/11 volts due to starter draw. A marked/decent improvement over the old ballast/starter draw condition....
 The feed I have picked for the primary activating coil of the relay is the "G" terminal of the TTS . This is a good place to tap into existing circuitry due to both it's proximity/location to the ballast and the fact that this terminal is also only energized when the ign. sw. is in the start/crank position. All other system circuits stay stock and are not interferred with .
 Some may have seen this done with starter feed and diodes to eliminate coil/ign feedback problems , but this is a better approach as it has complete isolation and no worry of voltage drop due to in-line diodes. Much better..
I use this in conjuction w/Crane set-up, but it will work with all..

 http://members.aol.com/ajdalton7/20002.jpg

[Cees Klumper]

I have been paying attention to this and the other Pagoda boards for years now and it's always nice to see something very new pop up. Somehow I get the sense I could do this install properly although, after reading your post only once Arthur, I must admit I haven't got a clue about most of its contents! I own a '69 280 SL - should I attempt this or is it not necessary you think?

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[A Dalton]

If you have the later Transistor/switch-gear ign, it is not  intended for that.
 It is for standard ign systems that used a ballast before most manufacturers found that by by-passing the ballast for starting was a much better system. Then they all did it by bringing power up from the starter or ign sw. to bypass the ballast during crank.... this is just an easy, basic way to do it on the early 113 systems.. Sorry if it was confusing, as I purposely made it as simple as I thought was possible while still be concise, including a simple diagram showing where to hook the 4 wires, along with the required part# for those who do not understand electronics.
 If anyone has questions that will help clear it up, I will be happy to try  to explain it out.....  

[enochbell]

Hey Arthur,

Let me try to catch up and take advantage of your suggestion, would you please let me know if I have caught your instructions correctly:

The object is to find a straight 12V feed to the coil by bypassing the ballast resistor only during cranking.

You tapped the hot wire from the TSS because it is live only during cranking, and used it along with a ground connection to provide 12V as long as it stays closed.

You connected one side of the igntion switch (from one side of the ballast resistor, I assume it is obvious which side, as the other side of the ballast resistor goes to the coil?) to the relay to cause it to close when you are cranking.  

You connected the other side of the relay to the coil side of the ballast resistor.

Now when you turn the key you get pure 12V juice to the coil?

Please let me know if that is correct, even if I don't have a clue on the theory side of it.  And thanks for your suggestion.  Heck, I don't even know what a ballast resistor is, sounds like somebody in charge of keeping excess weight out of the hull :-)


g

g

'64 230sl, fully sorted out...ooops, spoke too soon

[George Davis]

My car is a '69 with standard points ignition, but it has an extra original-looking wire that connects to one side of the ballast resistor.  I have not tested it, but I don't know what else it might be besides a ballast by-pass for starting.  Could it be that all 280 SLs have a ballast bypass?  Maybe I can remember to test it tomorrow.

By the way, Arthur, that's a neat little system!

George Davis
'69 280 SL Euro manual

[A Dalton]

Greg

 Yes , it is that simple
 The only technical thing you may want to understand a bit more is that in theory one would now get 12v at the coil b/c the ballast resistor [ which limits the V at coil] is out of the circuit [shunted]
 but in real time , the coil is only getting battery voltage , which is lower than 12v b/c the starter draws down bat voltage due to load .. that is the whole concept .. keep the Vs at the coil up for a hot spark even though the starter is drawing down the battery

 You have all else correct  [ as usual]
 One will notice that on the Crane 3000 hot race ignition sytems, they tell you to eliminate the ballast by shunting it with a heavy wire across the terminals.. effectively giving the ignition 12v all the time..  but we do not want that as we are just street guys and do not want to strian the ign components .
 But we do want a good spark at crank.
 You also mention bringing wire to the coil, etc..which is correct , but the easy way [ phyically ] is to just mount the wires from the relay right at the terminals at the resistor,[ one on each side] as they are right there for ease in hook-up,,,,

[A Dalton]

G D
 Your chassis has an extra set of contacts in the starter solinoid that feeds the coil only when the starter is energized . This is the exact system I use with the  remote relay b/c the earlier chassis did not have that extra set of contacts at the starter... so, we just add them up top
Same deal, same concept. same by-pass .. just we do it without having to change the starter/solinoid... we just add a set of contacts [relay] right next to the  ballast and get crank activation right across at the nearby TTS. Nice/Neat/Clean, short wires , etc...
 The extra wire you see/mention is the by-pass wire from your starter sol.. A .044 chassis starter feature not available on .042/043 ... that is why I specified early chassis...

 ..an added feature I use with this mod is to leave a stub on the relay at the wire from the TTS  "G" terminal so I can clip on to it anytime I want w/Remote Start/Crank sw.  By feeding Bat +12 to that terminal from a remote sw,. one can use this feature when doing valve adjust or any other maint adjustments that require engine rotation without energizing the CSV...no big deal, but it is there for those who know..

[ja17]

Hello Guys,
You can install the heavier duty starter which has much more cranking power. It bolts right up. The solenoid also has an extra terminal built into it for an ignition ballast resistor bypass.

As you probably know Arthur this is how they achieved the by pass on the later models.

So you get more cranking power, igntition ballast resistor by-pass, in an all original looking package.

Joe Alexander
Blacklick, Ohio

[A Dalton]

Yes , I know that .
 This relay is just a simple, low cost variant fix to get the upgrade of ballast by-pass for those who do not want to do a  starter change out until needed.
 I have made mention of the later sol. by-pass particulars  for that reason.

[Ben]

Arthur this IS a great mod !

I had it years ago on some old Ford I owned and I always wondered why the Merc never had it, but as you stated they simply didn't know at the time !

I believe I may have a later starter as my car (when the battery is good) sounds a lot different to other 113's I've heard cranking. The other seems lazier and more silent whilst mine really zips up !

I must take a closer look abd see if I have that extra terminal, if not I'll do the mod as per the diagram !

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

[jeffc280sl]

Arthur,

I have the Crane ignition system, red coil and 1.8 ohm ballast.  Is this something my 1970 SL could benefit?

Thanks,

Jeff C.
1970 280SL 4-speed

[A Dalton]

quote:Originally posted by Lax882@aol.com

Arthur,

I have the Crane ignition system, red coil and 1.8 ohm ballast.  Is this something my 1970 SL could benefit?

Thanks,

Jeff C.
1970 280SL 4-speed

J
 You have the best 113 ignition set-up [ my opinion,anyway] , but if you do not have ballast by-pass, it would still benefit from one...
The concept is that the ign system, no matter how good , suffers low voltage conditions when the starter is cranking. So, to offset that draw , a by-pass is a simple remedy. If you  already have a by-pass , you will see it at the coil side of the ballast.
 Even the high torque starters effectively draw down the available voltage to the ignition, which is why they have the by-pass solinoid as part of the package.
 Again, let me remind all.. this is just a simple mod for those early system that do not already have a by-pass. {I was always surprised they did not have this til late , as American car manufactures were using these circuits in the early '60s]]
 I was working on these cars when they were new and can remember guys doing ballast conversions on 108 chassis way back...
This is also a good reason to have a high crank Amps battery in place , as that also helps curb the starter draw down.

 ..While I have you on the horn, I emailed you several times to inquire how the high/low beam relay circuit we put together to eliminate the foot sw. to the Combo lever worked out, but I did not get a reply... did that work out to expectations??
Tnx
Arthur

[jeffc280sl]

Thanks,  I'll check for the ballast/coil wire.  I'm not sure if I have it.  If I don't I soon will.

Thanks,


Jeff C.
1970 280SL 4-speed

[A Dalton]

I can see from some replies that there is concern on whether one already has ballasr by-pass or not , so here is a very simple test for those who are not sure . This will save tracing wires and looking for starter/sol. circuits, etc.

 If one has a meter, set it to a scale to read 12v/DC.
 If one does not have a meter, a simple 12v test lamp will suffice..
[ if you don't  even have that , get one , if for nothing else, just to use for checking simple stuff like power, fuses and lamps]

 OK..., hook your meter/light on the ballast resistor terminal on the coil side of resistor . The other lead to a good ground. Turn key to run position.. you will read 8-9 Volts.
  Now, crank the starter and watch voltage..if the voltage increases, you do already have a by-pass..if the voltage decreases, you do not.
 This difference can be detected even with the test lamp as you will see the lamp brighten as starter circuit is energized if there is a by-pass circuit.[ which is what we want], or dim if no by-pass circuit.
Hope this helps those less inclined on electical matters.

[J. Huber]

Thanks for all the info AD, although it mostly greek to me...

Just curious, Can I ask what the end game is in this modification? I would imagine a quicker stronger start? Or does it take stress off the starter? coil? Distributer? Please humor me -- I really want to know!

James
63 230SL

[A Dalton]

quote:Originally posted by J. Huber

Thanks for all the info AD, although it mostly greek to me...

Just curious, Can I ask what the end game is in this modification? I would imagine a quicker stronger start? Or does it take stress off the starter? coil? Distributer? Please humor me -- I really want to know!

James
63 230SL

 It will improve your gas milage to 45 mpg and your car will start in 7 nano-seconds ..
 You said to Humor you , didn't ya

 It just lets the ign system retain a decent spark under the adverse conditions when the car is cranking over ..be it from  cold weather to a slight low battery..that's all...
The results are a faster start, which promotes less wear and tear on all assosciated parts/systems.

[J. Huber]

Thanks AD. You know you could have stayed with the 45 MPG and I'd a believed ya...

James
63 230SL

[A Dalton]

quote:Originally posted by J. Huber

Thanks AD. You know you could have stayed with the 45 MPG and I'd a believed ya...

James
63 230SL

..but that part was further from the truth than the short starting time exaduration.....

[hands_aus]

Hey Arthur,
Your original mod was for 230/250SLs so I looked at the 250SL wiring diagram.

Could the ballast ‘by-pass’ be made by adding a wire from Inj Pump Solenoid Relay terminal #87 to the Coil side of the ballast resistor?


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

[A Dalton]

quote:Originally posted by hands_aus

Hey Arthur,
Your original mod was for 230/250SLs so I looked at the 250SL wiring diagram.

Could the ballast ‘by-pass’ be made by adding a wire from Inj Pump Solenoid Relay terminal #87 to the Coil side of the ballast resistor?


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

 No..I can see why you might think that , but you have not considered what would happen when the starter is no longer engaged and the car is running. You would now have a feedback circuit of coil ballast voltage of 8-9 V feeding the FI pump solinoid .. you have created a definate No-NO...
 Although you may use any spot in the starter activation circuit w/relay. That is why I mentioned the isolation characteristics of the relay. That is what the relay is .. an ISO Relay..and that is why it is there ..to isolate the two circuits, while still be able to switch them on/off without feedback/shorting problems between start/run circuits.  I also mention diodes being used in these type circuits, but a bad choice for this application as they drop voltage and that defeats the purpose of what we are trying to accomplish.[which is getting full bat V to ign at crank]
 Anyway, as also mentioned , the reason I chose the "G "term of the TTS was its location and it's ease of tapping into the starter circuit b/c it has a screw terminal w/boot for a clean install, with the added benefit of its availability to be also used as a remote start tap for maint. work.
 Glad to see you toying with the  schematic though.. that's how we come up with this stuff.........................

[hands_aus]

[/quote]
 No..I can see why you might think that , but you have not considered what would happen when the starter is no longer engaged and the car is running. You would now have a feedback circuit of coil ballast voltage of 8-9 V feeding the FI pump solinoid .. you have created a definate No-NO...
 [/quote]

Hey Arthur,
I didn't see that feedback connection. I understand the FI solenoid potential problem.
The relay would be a simple and easy addition.
Did MB make a double pole single throw relay? maybe for a sedan?

The 250SL circuit is for a manual car and doesn't show the connections for the auto trans, kickdown and constant speed solenoid, or the auto trans pressure switches, idle switch etc.

I am looking for something similar on a sedan circuit. Could you suggest a typical model?

Thanks

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

[A Dalton]

<<Did MB make a double pole single throw relay? maybe for a sedan?>>

 If you are asking how it was finally accomplished by Benz, it was by adding a contact set in the starter solinoid. that is why the later starters have 3 wires on the solinoid.. What we are doing is just moving that contact iso circuit from the later starter design up to the ballast with a seperate relay so we don't have to go with later starter/sol for the up-grade.
 This circuit can be used on any car that has a ballast resistor ignition w/o a by-pass.  You simply have to find a convienient feed for the coil of the the relay so it is energized  only when the starter is cranked...if you can not find a good spot, you can always go down and grab it at the starter itself, but that takes more wiring.
 You can also use your direct jumper from the FI pump soinoid , but you have to put diodes in the line to prevent the feedback problem and, as explained , that drops available V , so that is not the preferred method.
 The RS relay is the ticket. But , you can also use a Benz Ice Cube relay . The same as they use for CSV will work. SPST is all that is required.
Or , if one wants to upgrade to the later high torque starter, run the ballast jumper from the new starter as it has the provisions already there for by-pass  that the early [.042.043] models did not have.
One way is expensive, one way is not .. the ballast improvement is the same  regardless of which way one goes/chooses.
If one needs a starter anyway, then I suggest the the former , if one doesn't , I suggest the latter.

[hands_aus]

[quote[br
>> If you are asking how it was finally accomplished by Benz,
[/quote]

Thanks for the additional info,

Actually, I was thinking that if there was an MB DPST relay available from a sedan of the same era I could hunt a second-hand one down and substitute the SPST Inj Pump Solenoid relay with it.

By adding the 'contact to ballast' wires it would achieve the same end-result but not additional hardware.

Relay mounting space is at a premium in the engine bay of my 250sl as it already has the CSV relay, Inj Pump Sol. relay, 1 sec. Time relay (my mod. genuine parts) and Wiper relay.

Any way it is achieved, I think this is a worthwhile mod to make.

Thanks

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

[A Dalton]

I hear you now..
 What you would want is double pole , single throw..both circuits out of single relay, but independent. Let me see what I can find in Benz hardware...
 You could also use the CSV relay for both CSV and pump sol. [ like th 230 does] and then use the FI sol. relay for ballast by-pass..
 specially where you have the 1 sec squirter system,,,,,,,,,,,,,

 * The RS relay I mentioned is a mini ice cube relay  , so it mounts right under the ballast without requireing lots of space .. It is also black with a one hole mounting tab, so not real noticable [ or easy to hide]

 http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F013%5F000&product%5Fid=275%2D226&hp=search

 

[hands_aus]

quote:Originally posted by A Dalton



 You could also use the CSV relay for both CSV and pump sol. [ like th 230 does] and then use the FI sol. relay for ballast by-pass..
 specially where you have the 1 sec squirter system,,,,,,,,,,,,,

  http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F013%5F000&product%5Fid=275%2D226&hp=search

I will look into that. It might be a good alternative.

The Inj Pump Solenoid (under a HOT start condition) would only be activated for 1 second instead of the full cranking time...probably not a problem. It would be controlled by the TTS under Cold Start conditions.

I must admit that I want to keep my car looking original without it being restored. The 1 second relay I used was from a 250SE sedan with correct coloured wires.

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