5 replies to this topic

[finch661]

85 mini - wiring diagram 17 in haynes 

 

after solving one issue, i have now another (typical). I had a bad rear right indicator, and found the rear wiring loom was pinched. that is all fixed, and indicators working as they should. however my hazards are not working, when switched on, the in-line fuse blows. 

 

i have checked the switch socket, and found a dead short on the green/white, which seems to be the left side indicators.  Now the fact that my indicators work as normal, suggests that the short is an issue with the rear loom. all indicators work, with no other shorts found. Looking at haynes, the green/white is joined to the indicator siwtch (for bypass).  I would have thought that if there was a short in this, using the  indicators would cause a fuse to blow as well?

 

any thoughts on what could be happening? 

 

thanks

 

Rich 

[weef]

Just to clarify your situation

The vehicle lamps are standard, no LED units.

You were working on the rear RH lamp unit.

Which fuse blows, the feed to the hazard flasher unit or the feed to the indicator flasher unit and are the fuse ratings correct ?.

The wiring diagrams I looked at, I dont use Haynes, show the Green/White wire is associated with the RH lamps.

The Green/White wire as does the Green/Red  goes to the indicator stalk switch.

The resistance to earth for these wires is low so it is worthwhile comparing the Green/White and Green/Red readings, checking and subtracting the resistance of your multimeter test leads.

If you get back with the above information I might be able to help you with the problem.

[finch661]

Just to clarify your situation

The vehicle lamps are standard, no LED units.

You were working on the rear RH lamp unit.

Which fuse blows, the feed to the hazard flasher unit or the feed to the indicator flasher unit and are the fuse ratings correct ?.

The wiring diagrams I looked at, I dont use Haynes, show the Green/White wire is associated with the RH lamps.

The Green/White wire as does the Green/Red  goes to the indicator stalk switch.

The resistance to earth for these wires is low so it is worthwhile comparing the Green/White and Green/Red readings, checking and subtracting the resistance of your multimeter test leads.

If you get back with the above information I might be able to help you with the problem.

Hi thanks for replying

So, to confirm;

1) All standard units, apart from the flasher units, i upgraded to flasher relays about 10 years ago - ihave checked these and they work correctly

2) i was working on the rear right hand unit. I was using the hazards to test the lights during my fault finding. they only failed after the rear loom was touched

3) the inline fuse the the hazard flasher (which also supplies the interior light)

4) i agree, seems to trace back to that

5) I agree

6) i will do this tonight and report back!

[slidehammer]

Could it be a fault in the Hazard switch or the hazard relay? as the power for the indicators runs through the hazard switch. The idea being when you turn on the hazard lights it isolates the indicators so they can't both be on together.

[weef]

Thanks for the information.

As the direction indicators work as per design eliminates the wiring loom going to the lamps, the lampholders, the stalk switch and the direction indicator flasher relay. As it is the permanent live fuse that blows points to the wiring associated and components in this circuit.

My understanding of the wiring is as follows

From the permanently live fuse the Purple/Orange wire feeds the hazard flasher unit, and from the flasher unit the Light Green/ Pink feeds the hazard warning switch and as the fuse only blows when this switch is operated I presume these wires will be OK.

I can only see two earth paths here, either the flasher unit shorts to earth when operating or the switch shorts to earth through the inbuilt operating lamp circuit.

To fault find I would first check the switch circuit, two methods, either by substitution with a known good switch or by unplugging the switch and linking the Light Green/Pink, the feed from the hazard flasher unit, to the Green/Red and Green/White, the external lampcircuits, on the wiring loom plug. Remove the fuse, fit the links, reinstate the fuse and if all is well the external lamps should flash as per design and suspect the switch to be at fault, if the fuse blows it points to the hazard flasher unit as being faulty.

If the fuse blows reinstate the hazard warning switch in the circuit and move to the hazard warning flasher unit. Again try by substituting with a known good unit or remove the flasher unit and link together the Purple/Orange and the Light Green/Pink on the loom plug. With a good fuse fitted turn on the hazard warning switch and the external lamps should light but not flash and hopefully the fuse will not blow. If this is the case suspect the hazard warning flasher unit.

If the fuse blows I will have to give this a bit more thought.

Hope this helps with your problem.

[finch661]

Could it be a fault in the Hazard switch or the hazard relay? as the power for the indicators runs through the hazard switch. The idea being when you turn on the hazard lights it isolates the indicators so they can't both be on together.

 

Could it be a fault in the Hazard switch or the hazard relay? as the power for the indicators runs through the hazard switch. The idea being when you turn on the hazard lights it isolates the indicators so they can't both be on together.

 

 

Thanks for the information.

As the direction indicators work as per design eliminates the wiring loom going to the lamps, the lampholders, the stalk switch and the direction indicator flasher relay. As it is the permanent live fuse that blows points to the wiring associated and components in this circuit.

My understanding of the wiring is as follows

From the permanently live fuse the Purple/Orange wire feeds the hazard flasher unit, and from the flasher unit the Light Green/ Pink feeds the hazard warning switch and as the fuse only blows when this switch is operated I presume these wires will be OK.

I can only see two earth paths here, either the flasher unit shorts to earth when operating or the switch shorts to earth through the inbuilt operating lamp circuit.

To fault find I would first check the switch circuit, two methods, either by substitution with a known good switch or by unplugging the switch and linking the Light Green/Pink, the feed from the hazard flasher unit, to the Green/Red and Green/White, the external lampcircuits, on the wiring loom plug. Remove the fuse, fit the links, reinstate the fuse and if all is well the external lamps should flash as per design and suspect the switch to be at fault, if the fuse blows it points to the hazard flasher unit as being faulty.

If the fuse blows reinstate the hazard warning switch in the circuit and move to the hazard warning flasher unit. Again try by substituting with a known good unit or remove the flasher unit and link together the Purple/Orange and the Light Green/Pink on the loom plug. With a good fuse fitted turn on the hazard warning switch and the external lamps should light but not flash and hopefully the fuse will not blow. If this is the case suspect the hazard warning flasher unit.

If the fuse blows I will have to give this a bit more thought.

Hope this helps with your problem.

both thanks for the advice. spent a fair bit of time last night going though each circuit, removing the flashers, and rear loom (and so on). all seemed to work as it should. i took apart the switch and bridging the contacts again all worked. with he switch partially rebuilt, all worked ok.

 

As both of you have suggested, i then happened to check the actual bulb connectors (in the switch), and found it was a dead short. reconnecting the bulb connectors and it blew the fuse.  new switch orded!

 

thanks for your help!