Which wires go ballast resistor

[awolff280sl]

Does anyone have a picture they can post of the wires going to the ballast resistor on a 280sl, that is without any modifications. On my car, one wire originates out of a large trunk of wires running over the wheel well. The other wire runs separate but along with this trunk and appears to enter the relay that is hanging from a "swung-out" bracket. The engine is apart and I cannot turn the ignition switch to determine which wire is coming from the ignition and which is going to the coil. I just need to see a picture of where each lead is coming from and then I should know. Hopefully my desription makes sense to someone. Much appreciated!

Andy
Sarasota, FL

[merrill]

you may find a photo at this link


http://www.motoringinvestments.com/MainPage.htm

I have a 230 so I cannot supply you a photo.

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[awolff280sl]

Thanks Matt, but I could not get enough of a close up of the area to make out the wiring.

Andy
Sarasota, FL

[J. Huber]

Like Matt, I have a 230 and no photo on hand. But for sake of comparison -- mine goes like this: a wire comes off the large wiring bundle to one side of 1.8 ballast. On the other side of ballast a wire goes to the left terminal of red coil. The other terminal on coil goes to distributer. Very simple set-up.

James
63 230SL

[awolff280sl]

OK Matt, maybe I can infer that since we both have a wire coming out of the large bundle, and that the other wire is going to the coil on the 230, then the wire out of the bundle should be coming from the ignition. And on the 280, the wire to the coil detours through a relay.

Andy
Sarasota, FL

[Benz Dr.]

What year is your car? After mid 1969 all US bound cars had a different ignition system than earlier or Euro cars.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[awolff280sl]

1969

Andy
Sarasota, FL

[awolff280sl]

Below is a picture of the 4 relays mounted along the driver's side of my engine bay. Perhaps someone has or is familiar with this arrangement and could tell me the name and/or function of each. I am particularly interested in #4 (the one hanging from a "swung-out" bracket) because this one receives a wire from the ballast resistor.


Download Attachment: 4- RELAYS.jpg
43.5 KB

Andy
Sarasota, FL

[jeffc280sl]

Andy,

Relay 1 is for the wipers.  Relay 2 is part of the cold start system.  Can't say where 3 and 4 belong.  I don't have either of them in my car.  I suspect ohne of them may be part of a MB mod to make the car easier to start when warm.  I'll see if I can find the details and get back to you.

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

This thread may help.  JA17 posts a pic at the bottom

http://sl113.com/forums/index.php?topic=6823,relay

Jeff C.
1970 280SL 4-speed

[Richard Madison]

Andy is pateintly waiting for the scoop on Relay Number 4. Let's not hold back, please tell Andy what Number 4 is.

Richard M :0)

[hands_aus]

Relay #1 wiper

relay #2 inj pump start solenoid

Relay #3 is for the CSV (inlet manifold)

Relay #4 could be used to by-pass the ballast resistor only during start-up.

This provides full battery voltage to the coil and hence a stronger spark.

The 230sl and 250sl starter motor does not have the extra contact which provides this function where the 280sl did have the extra contact.
This is speculation.

Have you tried disconnecting the relay and seeing if the car will start?

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

[awolff280sl]

Thanks Bob (and Richard for the prod). Bob's speculation was the only idea that made sense to me given that wire from the resistor. It won't be ready to start for awhile, so I won't know until later. However. on the phone today with Gernold, basically the setup should be: ignition wire to the resistor, and wires to starter and coil. The ignition wire should come out of the bundle just before the mounting site for the resistor, and mine does. And the wire to the starter should come out of the bundle just beyond the mounting site for the resistor, but mine doesn't. I removed the electrical tape around the bundle in that area looking for a cut wire or some indication of that wire, but nothing. Gernold thinks the 4th relay is for emissions. In any event, I may end up running a wire from the starter terminal block to the resistor. Strange thing is that the car was starting
and running well with this configuration, whatever that may be.

Andy
Sarasota, FL

[awolff280sl]

I wanted to update the members on my struggle to understand the ignition wiring of my '69 280sl. Gernold called that he found notes that he took regarding late '68/early '69 sl's. According to Gernold, and my understanding, these cars have an "L" bracket (what I've been calling a swung-out) that holds a 4th relay. This relay functions to deliver 12v to the coil side of the ballast resistor during cranking by means of a wire from the starter. Now as it turns out, these cars were already equipped with the upgraded starters and alternator terminal blocks (the one located on the passenger side of the pan) that allowed for this wiring. That is, on 230's and 250's, that terminal has 2 wires, and with the 280's there are 3, with the 3rd being the 12v coil feed. Later 280's sent 12v to the coil directly from the small connection on the back of the starter via the wire that exits the bundle just beyond the resistor, ie no relay. We do not understand the reason for this apparent redundacy, but maybe it has something to do with the timing of the production of the upgraded starter. Anyway, I won't know this for sure until the car can be started.

Andy
Sarasota, FL