DT 175 MX Electrics Again!

[JacobHendry]

Hi guys, back again for some advice. Took the bike for it's MoT today, unfortunately it failed. Main reason was because of the horn. It was pouring rain all the way there and the horn refused to give more than a squak, even dried out. Ordered another one from Yambits so should be here tomorrow. Other failure point ws something I mentioned before. When the indicators are on the lights dimm/flicker/flash/"are adversely affected by the operation of another lamp" as the lad put it. Also when the horn button was pushed same thing happened. Could this be a bad earth somewhere? If so, is it just a process of going through all of them or are there any more likely than others? Or is it something else? Any help much appreciated.

Paul

[Airhead]

Your bike is probaly older than the 'Lad' whose testing it. Its a crappy 30 year old 6v systam, so wat if a light dims when you push another button, next year take it somewhere else.

As for this year, make sure the battery electrolyte is topped up bwith de-ionised water, fully charge it overnight, check and clean any grounds you can find. As for ther horn, take a jumper direct from battery positive unplug the wire thats is NOT black and touch the jumper on the horn terminal.

If it works you need to strip down the horn push and clean the contacts

If it doesnt you need a new horn, of a new battery, or charge the battery etc

my money will be on cleaning the horn push contacts.

[JacobHendry]

Thanks for that, just about to go outside and start earth hunting!

[JacobHendry]

Now for the update on this saga. Tried every earth wire I can find, checked every cable and everything seems to work as it should, including new horn being impressively loud. The guy at the garage also mentioned that the rear indicators did't seem to be very bright compared to the front, so eventually checked the bulbs - 8 watts instead of 18 or so. Never thought to check this as they were brand new from Red Rose in Yorkshire. So as I needed to buy bulbs anyway I decided to get another flasher unit, even though it was a new one I had put on, just in case it was draining power. Put bulbs and it all on today but no joy, still the same problem. The side light and tail light very obviously flash/dim when the indicators are on. When the indicators are in the flash cycle these two bulbs go very very dim, when the indicator changes they sharpen up to their normal light.

So I'm back to square one. I know it's a crappy 6 volt system but there must be something draining the current because if you were standing in front of the bike and the indicators were on, it really looks like you have a white flashing light, not just dimming, working out of sync with the indicators. Out of ideas now.

I can get it passed without the indicators but it took me ages to find the wiring in the loom and get them working that I really want them to work!!!

(Aaaagh sound of frustration)

[Airhead]

I would try to jumper a live wire from battery positive directly to the flasher relay signal. Cant put any detail on that until later.

If it fixes it the problrm may be a dirty / corroded contact in the flasher handlebar switch.

However, more likely the main keyswitch I think as this switches the battery 6V to auxilliary equipment and switches. I suppose a jumper between the red and brown may prove or dis-prove this, but again I am guessing, will check later.

[Cynic]

Cor you really really want the bloddy things to work. Phew.

One cheat is to use lower wattage bulbs all round, the lamps are not as bright but take less power to 'work'. The battery needs to be absoloutly first class, no issues whatsoever.

The power for the indicators comes from the ig switch, its a brown with a white tracer and powers everything else too. So if the indicators are on with the lights and the horn, throw in the brake light no chance.

What actually happens is, power goes to the ig switch. From there to the indicator relay, from there back to the switch at the bars and its here that the right /left bit is decided (The contacts in here are probably one of the primary problems). The lamp in the taco uses whatever side is not in use as the earth for the lamp as there is not enough power after the lamp to light the lamps on the other side(no shit).

[Airhead]

With the benefit of the wiring diagram now...disconnect the two pin plug socket from the flasher relay. Link the Brown/White back onto the relay. Jumper from battery Positive to the other pin where the Brown would have gone, Now try again, this takes the indicators away from the keyswitch, if it is any better you need to clean the contacts of the keyswitch or replace it.

[JacobHendry]

Thanks for that guys, can't try anything out at the moment, son is getting married in a couple of hours! will be back at it again at the weekend and let you know how it goes.

Paul

[JacobHendry]

Back again guys with an update. Been away with the grand-rug rats on holiday so haven't managed to do much. They go home tomorrow (tiredly thankful he says)

Tried the jumper from the battery to the relay, but no luck. Side light and rear light still flash when the indicators are on, but one thing that I have noticed, that I hadn't paid attention to before, is that is that the rear light flashing is actually a lot less obvious when compared to the front. Hmmm.

I did actually replace the ignition switch when I got the bike as the original one was knackered.

Would doing the same for the lights (ie jumper them from the battery) help with any solutions?

Paul

[Airhead]

Try disconecting the 6 way plug/socket to the lights switch in the headlamp shell. With lights switch ON check with a multimeter, there should be no or very little resistance between

1: Brown and Blue/White

2: Yellow/White and Yellow and Blue (in any combination)

Also check the condition of the plug and socket

[JacobHendry]

Had a look at the light socket wiring today, and am slightly confused. My wiring colours are different from what you said and the 2 wiring diagrams I have!

I have in the six wire lighting socket the following:

Black Red/White Blue/Red

Dark Brown Brown/White Green(dark?)

plus a single Green, Yellow, Blue and the Pink.

The loom side is identical other than the Dark Brown and Green(dark?) have 2 wires into their connectors.

So I'm struggling to work out the corresponding wires to check (and also wondering why I have a different wiring scheme)!

Confused!

[nayruf]

Cor you really really want the bloddy things to work. Phew.

One cheat is to use lower wattage bulbs all round, the lamps are not as bright but take less power to 'work'. The battery needs to be absoloutly first class, no issues whatsoever.

The power for the indicators comes from the ig switch, its a brown with a white tracer and powers everything else too. So if the indicators are on with the lights and the horn, throw in the brake light no chance.

What actually happens is, power goes to the ig switch. From there to the indicator relay, from there back to the switch at the bars and its here that the right /left bit is decided (The contacts in here are probably one of the primary problems). The lamp in the taco uses whatever side is not in use as the earth for the lamp as there is not enough power after the lamp to light the lamps on the other side(no shit).

Hi, I had the same problem with the indicators on my twin shock DT, I put lower wattage bulbs in the fronts, and the lowest wattage indicator instrument bulb I could find in the speedo/tacho, I manage to get the indicators to flash at about a rate of 60 per/min, I think the legal requirement is 60 to 120 per/min, I also fully charge the battery up prior to the mot and also turn the tickover up a few rpm, The bike has passed 3 mot's so far and the test station has not picked up on the indicators yet.

[Airhead]

Had a look at the light socket wiring today, and am slightly confused. My wiring colours are different from what you said and the 2 wiring diagrams I have!

I have in the six wire lighting socket the following:

Black Red/White Blue/Red

Dark Brown Brown/White Green(dark?)

plus a single Green, Yellow, Blue and the Pink.

The loom side is identical other than the Dark Brown and Green(dark?) have 2 wires into their connectors.

So I'm struggling to work out the corresponding wires to check (and also wondering why I have a different wiring scheme)!

Confused!

[Airhead]

Ah thats because it's a 4J3 (DT125MX) and 4J4 (DT175MX) UK models wiring loom

[blackhat250]

Just my tuppence " Has the indicator switch[ light switch ] been renewed at any time? coz two type are availible, one has an extra conection in the six pin plug[ usa type] Europe/ uk has only 5 , one is empty.

i tryed this swap on DT, and caused similar probs,

[Airhead]

I take back what I said, the confusion lies because we were both looking and trying to fault find from the WRONG bloody diagram...thanks Haynes.

Ironically in my OTHER Haynes manual I find the right diagram

[JacobHendry]

Ahaha, and the bike is a 2K4. So wonder why it has a different loom then? Do you know off the top of your head which corresponding wires I need to check?

[Airhead]

Ahaha, and the bike is a 2K4. So wonder why it has a different loom then? Do you know off the top of your head which corresponding wires I need to check?

PM me you email address and I will scan the diagram for you, then at least you can see what youre doing, I havent looked at the problem with regard the correct diagram

The wrong diagram is in haynes ISBN 0 85696 661 4

The right diagram is in haynes ISBN 1 85010 300 3

This is the best one, cant understand how they got it so wrong in the other

http://cgi.ebay.com.sg/Yamaha-DT175MX-Haynes-Manual-DT125MX-DT175-DT125-DT100_W0QQitemZ150447971503QQcmdZViewItemQQssPageNameZRSS:B:SILF:SG:101

In the 'Wrong one'

They state the diagram is for DT175E and DT175MX...clearly it is for DT175E but not MX, look at the diagram, keyswitch is just two position and no parking lamp. Muddies the waters somewhat when youre trying to fix a lighting issue.

[JacobHendry]

Hi guys

The switch certainly looks original and has six wires.

Haven't tried lower wattage bulbs, certainly an idea. I'll see if I can get some tomorrow.

Thanks for the wiring diagram Paul, it's very obvious now that you mention it that I had the wrong one, just didn't occur to me. Did have an idea which I don't know whether it's possible or not. I've discovered that you don't actually need a front side light for the MoT so by removing the bulb I remove the poblem of it flashing in time with the indicators. I still though have the problem of the rear lamp still flashing, albeit not as bad as the front light. Would it be possible to somehow disconnect the power to the tail lamp on the second key position ie when the side light goes on, and only have it lit when the actual light switch is in the on position? Mind you, I don't know whether it would still flash with the headlamp on do I!

[JacobHendry]

Well, have tried with low wattage bulbs all round, still same problem. Tried a new earth from the rear light, another earth from the battery, still no change. I'm going to just take the indicators off and get the MoT, then shove them back on, and try to enjoy what's left of the summer on the bike. Nice weather up here at the moment!

Thanks for every bodies help.

Paul