Thanks to Mike in Scotland I am now the proud possessor of a 3696 Br86 and what I believe is a 3656 Ae6/8 Crocodile. They run beautifully and I am very pleased with my purchases. They join one other loco of similar vintage in my loco roster.

Because 36xx locos were manufactured prior to Central Stations becoming available, the instruction books make no reference to the functionality of the front and rear lights and my three 36xx locos show different characteristics whan placed on the track. Can someone help me by explaining what behaviours these locos should exhibit?

Here is what I have and what they do:
3657 (Br103)
A headlight icon appears on my CS2 and and this turns the headlights on and off. These lights change end according to direction but there are no red tail lamps.

3696 (Br86)
No headlight icon appears on the CS2 (although a Telex uncoupler icon does, and this works correctly). The headlights at both ends are on continuously whenever the loco is on the track and these are unaffected by direction or any CS2 function. I have added a headlight icon to my CS2 for this loco but it makes no difference (maybe I picked the wrong channel?)

3656 (Ae6/8III)
A headlight icon appears on my CS2 and and this turns the headlights on and off. However, they only work in one direction and I think that a modification has been made to the locomotive. On removing the body sections I found that at one end, there are two white bulbs and at the other end one white bulb and one red bulb (that is, a bulb that appears to have been 'painted' red using a felt-tip pen or something similar). In addition, the light guide at that end has also been 'painted' red. The effect of this is that when working in one direction I get three white lights at the front and three red lights at the rear. However, when I reverse the loco, I get no lights at all.

I am further confused by the Croc in that the two bulbs at each end are separated by a 'shield' cast into the bogie which suggests that under certain circumstances they might operate independently, but as there is only one light guide, I can't see the point in this.

As is often the case, the loco handbooks are totally silent on the head and tail lamps, so can someone give me some advice on what I should expect? Also I have downloaded the exploded parts plan for this loco but the wiring diagram on it is for 3352 (non-digital), so can someone point me at a wiring diagram for 3652/3656 if I need to check the wiring?

Finally (phew!) you will have noticed that I am being cagy about exactly which model of the Croc I have. The box says 3652 but all the 3652's I can find are brown, whereas mine is green. Also its decoder has potentiometers for acceleration and breaking delay adjustment which I think also points to its being 3656, not 3652. The handbook is common to 3352/3556/3652/3656 so I get no help from that. I know there are lots of Croc experts out there so can you get a fix on what little beauty I have?

Thanks in anticipation, as always.

Edited by user 01 January 2013 22:17:58(UTC)  | Reason: Not specified

Hi Robert,

The 3657 and 3696 are working as intended. Remember that in the original Marklin digital format there was only one function available. This was usually used for the lights, but in the Br86 the lights were left fixed and the function was used for the telex couplers. Most Marklin locos of this period did not have working rear red lights, unless they had been modified by the owner.

You are right in suspecting that your crocodile is not a 3652, which would have been brown. A green croc with a 6080 decoder would be a 3656. However, if the decoder has potentiometers for max speed and acceleration/braking, then this is not a 6080 decoder, but a 6090. Therefore your loco, if this decoder was fitted from new, would have been a 3756.

The issue with the lights is a bit confusing. These locos would have had 3 white lights at the front, and only 1 white light at the rear (bottom right), if it has the correct Swiss light function. It looks to me like a previous owner tried to make the rear light light up in red by colouring in the bulbs etc with red paint or ink. Maybe he also thought that all three should light up at the back, and altered the wiring accordingly.

You should change the wiring so that the central bulb is connected with the offset one at the other end on one light output from the decoder, and the other light output should be connected to the centre bulb at the other end and the opposite end offest one. I hope you get what I mean.

Yo! Great answers - Thanks to all.

The Croc does have a booklet for a 6090 decoder with it, but I haven't given this much attention - maybe I should. I thought this was the original fitting as everything looks very neat and tidy but maybe it's a retrofit. I think that it is possible that the 3696 has also been backfitted with a 6090 so it's the lid off that one again to check. Does that make any difference to the functionality of the lights?


Just to confirm, are you saying that the correct (prototypical) rear light display for a Swiss loco of this period should be 1 white light? If so, that answers all the questions and it easy to rectify.

Thanks again for the very prompt and helpful replies.

Robert,

I also think these loco had a subboard with diodes to achieve this light change.

Thanks to all. I am going to have a play around with the Croc this weekend, but I can report that my 3696 has no visible potentiometers for speed/acceleration control.

and no ball bearing

Here the link to the Italian Forum "3Rotaie" (means 3 rails) with an interesting discussion on croco's
For non regular users, this is the final file:










It's in Italian, but I think easy to understand

Hi John,

Marklin don't put ball bearings on any of their locos, as you well know. Also all motor kits made by Marklin include new brush plates, but none of then are fitted with ball bearings either.

The advantages of installing ball bearings are well documented on this forum, but few have the expertise or tools to be able to fit these ball bearings without the risk of ruining the model.

I have converted many models to digital in the past, but I don't feel confident I could drill the chassis or brush plate successfully with the tools at my disposal. I'm quite happy to live with the motor bearings as they were intended by Marklin, adding a drop of oil now and then when the loco makes a bit of noise to show that the bearings are dry.

Now, if Marklin started making factory kits with ball bearings I might be tempted to change mine, assuming the price is reasonable.

Hi Robert.

I can confirm that the 3656 SBB Ce 6/8III 14.305 had a 6080 decoder and "swiss lightchange", 3 in front and the lower rear right, all white.

After a lengthy wait for a 60942 decoder, work to upgrade my 3652/3656 Croc is now underway and progressing well. However, I have hit a snag and as usual I am looking for some advice.

My plan was to replace the c90 decoder and filament lighting in the loco with a 60942 decoder, and LED lighting fed from a 606218 board, making the head and tail lamps on my Croc operate like those on the more modern 39560 version, in true Swiss style. I have been following a couple of threads to find out what to do, the one on this board being < https://www.marklin-users.net/fo...--29510-Starter-Set.aspx > which has been invaluable.

With the new decoder in place the loco registered itself on my CS2 with no problems and it motors beautifully. So far as the lights are concerned, I can get the 3 white front and 1 red tail light to work in both directions of movement, but I cannot get the 1 red to change to 1 white in SBB fashion. I have selected F1 as the function key to do this and followed the instructions in the threads slavishly, but when I press F1, rather than the red tail light changing to white, all that happens is that all the lights start to flicker rapidly. It does not matter which way round the loco is travelling, the effect is the same. There is no flicker at all when F1 is not pressed so I do not think that this flicker is a case of the track voltage getting on to the light circuits.

Both of the threads that I have used are a few years old and used 6090x decoders, so there is reference to a violet wire from the decoder to the circuit board, My 60942 has no violet wires and I have used one of the decoder ground (orange) wires instead, but I wonder if this is the problem.

Any advice on what may be causing these effects will as usual be much appreciated.

Incidentally, I have been taking photos of the work as it has progressed and I will put these up here, together with a description of what I have done and my experiences, in due course.

Happy New Year to All!

Thank you for this advice. The Pin 20 route seems most elegant but how do I identify it?

Thanks for the update Tom. I have done some checks on the decoder board and can confirm that Pin 20 is taken to 2 unused pads on the top of the decoder. I have updated a drawing I attached to a different post to reflect this, which may be of use to others.

I have removed the orange wire from where the violet wire should have been and replaced it with a connection to decoder Pin 20 but, while the flickering has stopped, pressing the F1 key now has no effect at all.

Apart from registering the loco and changing the icon for F1, I have done nothing to the CS2 for this loco. Do I need to change anything there?

Further help would be gratefully appreciated.

Hi Robert

Here you may see how I did it:
Crocodile conversion