MZ TS 250 brake light relay

[motorclocks]

Does anyone have a TS 250 with the relay in your battery box, trying to find out where wires hook up thought i marked everything when disassembling wrong. I have a white wire going to front brake hub it is attached at the relay with a brown wire, don't know where to attach it. I have a single black wire coming from rear wheel drum switch don't know where to attach it.
all the wiring diagrams I've seen don't include relay. if someone had a pic of connection block that would be appreciated, again wiring diagrams are different than this bike, i have a parts bike and its wired differently
Thanks so much Dave 47, Blurredman, Nice2Day

[nice2day]

The "relay" you mention is the flasher unit for the direction indicators. The stop light switch on the rear wheel simply earths the return from the stop light bulb which is powered directly (via a fuse probably) from the main ignition/lighting switch. If the front brake has a similar built in switch like the rear one then all you have to do is to connect this wire up to the same black wire that feeds the rear brake switch. This can be done at any convenient position on the bike. Either one will simply earth the brake light bulb to earth to complete the circuit....or both together, it won't matter.

Les

Click on image to magnify:

[Blurredman]

That is a four prong relay-

Mz's only seemed to use two pronged.. So it seems like previous owner has done some re-wiring

I've done similar in the past.. I used to have a relay that when switching to high beam, low beam would also be on..



Having a quick look at the wiring diagramme that Les has kindly supplied, the black wire goes to the rear lamp, to complete the brake light earth. I suppose as Les says however it can go to any earth. I quite like these brake 'switches'. Most people don't understand them and just end up throwing them away for a modern plunger type, but that's their loss.

I think the black wire from the brake switch is unrelated to your query regarding the indicator relay. The brake light wire goes to the lamp, the relay I think is just a workaround from not being able to procure a two prong version..

[dave47]

Les, you might want to edit your answer as its somewhat misleading.
Its a relay, not a flasher unit, and is definitely non-standard, so hard to advise how to connect it.
There are no wires to the front wheel as standard.
The black wire from the rear hub goes to the brake light via the connector block and a black wire.

[nice2day]

Hi Dave...Ok I didn't realise this can was a relay, it looked like the indicator flasher unit at a very quick glance. The questioner, it seemed to me, was asking how to get both the brake light switches to operate and I explained the basic wiring IE: ignore the relay/or flasher unit...so I wasn't particularly worried what the can was.
However the rest of what I said requires no change.
I do know the standard bike has no front brake light switch but the questioner seemed to imply he had a brake light switch on the front brake drum.

I have a white wire going to front brake hub

As this would have been possible to fit by a previous owner, I was assuming that the brake plate had a similar switch to the rear one. and the questioner knew or was implying he had a front brake switch on the drum. If that IS the case then what I said is the simple method to get it to work.

Perhaps further explanation and clarification of the problem would now be worth making?

Les

[dave47]

Point taken. A picture of the front wheel would clarify.

[Blurredman]

The mk 1 ts's did have a front brake drum switch same as the rears that continued until '89.

I have no knowledge of the mk 2 TS's so I honestly don't know if they had a switch at the handlebars, or none-at-all.

[dave47]

I've owned a couple of TS250s and neither had a brake light switch. Some of the drum braked ETZs might have had them, and perhaps the OP has a wheel or brake plate from one of them.

[GMS250TS]

Did you ever work it out? I have a 1974 and I have the same set up, relay in the battery box , and everything works except brake light..front or rear. Did you get a new relay or rewire? If new relay what and were did you find one. I have Hella 4RA002566-07 relay and I think its bad when I hit the front brake it makes a click noise in the relay.

[GMS250TS]

Any help ?

[Blurredman]

Unfortunately a lot of people disapear.. Not a surprise specifically from someone with only 4 posts I'm afraid..

[mr_luke]

Your 4RA002566-07 relay appears to just be a standard 6V relay. There's an image of the datasheet available here: https://www.classiccult.com/hella-fog-light-relay-6v-nos.html

You could test it by applying power to pins 85 and 86, and checking for continuity between pins 30/51 and 87, either with a multimeter or a test light.

If it is faulty, any 4 pin 6V relay will do, such as this one, if you're in the UK: https://www.vehiclewiringproducts.co.uk/c-219-relays-flasher-units/p-1124-6v-4-blade-relay

[dave47]

Here in the UK some owners of the 6 volt MZs ran the headlights through relays, but I don't think anyone did that with the brake light. It works alright without one if there is only a rear brake switch. Is this also an American bike? Were 2 brake switches a legal requirement? Did the US importer add these because them was too much voltage drop in the front brake switch circuit? Just curious.

[GMS250TS]

Thanks Mr_Luke
and yes dave47 the bike is in the US, has front and rear to the relay

[a spooky ghost]

A bit late to the party. I spent a decent amount of time going through the rats nest of wires on my TS 250 (USA) bike. Instead of that hella relay, someone wired in a horn relay.

So that front light switch grounds out. The USA bikes got Lucas lights, the rear unit only has one bulb. Since shorting straight to ground isn't a good idea. Thats where that relay comes in.

A crafty fix, for a stupid problem... The right way to fix it, would be to use a 2 wire light switch. Just saying...