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ukdave2002
Joined: 23 Nov 2007
Posts: 4105
Location: South Cheshire
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 Posted: Mon Mar 14, 2022 10:31 am Post subject: |
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| Ray White wrote: | | ukdave2002 wrote: | Hi Ray
The circuit looks correct assuming the car is negative earth. If the diodes have failed due to excess heat they could fail either open or short circuit, if they have failed short circuit then the current from one side of the turn indicator would be fed to the other side, I can't see why this would damage your switch, but need a schematic of the switch internals to confirm.
One other issue could be that the warning lamp is short circuit, in which case switching the indicators on could create some sparks! but hopefully just blow a fuse!
Dave |
Dave the car is Positive Earth but the dash is on the bench and I am just wiring up and testing. I have ordered some 1A diodes as suggested. The diodes are now de soldered and I am going back to square one.
To be honest I am well out of my comfort zone. Some might say out of my depth.  |
In that case the diodes are the wrong way round, I'm just trying to figure out what may have happened when it was all connected up! ; these diagrams may help:
The cathode side of the diode is marked on the diode with the band.
Dave |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Mon Mar 14, 2022 11:09 am Post subject: |
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Dave, you are very kind. I tested the diodes with my multi meter on ohms and nothing passed either way. I tried again with 6 volts connected to my test lights and again nothing.
Originally I got something with 12 volts and the indicator warning light came on but didn't flash so after the switch flashed inside I went to six volts but thinking about it I should have a fuse in there somewhere and I forgot about it being positive earth. |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Mon Mar 14, 2022 12:38 pm Post subject: |
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I have just tested the diodes again having unsoldered them from the circuit... and they work O.K. with a 12 volt current but nothing happens with the multimeter.
I tried both + and - earth so I don't know what happened there!!
However, I will fit the new ones as you suggest as they are lower amps.
I took off the switch/flasher and tested it with 12 volts. The switch passes a current and lights up the test lamp on both left and right side wires ...but the flasher doesn't click or flash the test lights, so I imagine it is no good.?
What have done before with one of these switches has been to remove the flasher innards and taken the wires to a separate flasher unit. I have one of those to hand. |
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MVPeters
Joined: 28 Aug 2008
Posts: 822
Location: Northern MA, USA
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| Posted: Mon Mar 14, 2022 1:27 pm Post subject: |
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A separate flasher is the simplest solution, Ray. A benefit is that if you ever fit LEDs all you need is an electronic flasher unit.
Conventional thermal flasher units need a 'load' of 2x21W incandescent bulbs in order to operate & flash at the correct rate.
_________________
Mike - MVPeters at comcast.net
2002 MINI Cooper 'S' |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Mon Mar 14, 2022 2:54 pm Post subject: |
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| MVPeters wrote: | A separate flasher is the simplest solution, Ray. A benefit is that if you ever fit LEDs all you need is an electronic flasher unit.
Conventional thermal flasher units need a 'load' of 2x21W incandescent bulbs in order to operate & flash at the correct rate. |
Many thanks. That would explain a lot.
You don't know what you don't know  |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Mon Mar 14, 2022 6:07 pm Post subject: |
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I found this... (forgot I had it)...It is LED / electronic / + earth.... so is there anything I need to know about fitting so I don't stuff it up?
Will it work with my normal bulbs?
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MVPeters
Joined: 28 Aug 2008
Posts: 822
Location: Northern MA, USA
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| Posted: Mon Mar 14, 2022 10:41 pm Post subject: |
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Yes. X = -12V from an ignition-switched source.
No. I doubt if it will work with incandescent bulbs. Check with classiccarleds.
Note: Some LEDs are polarity-sensitive so stick with classiccarleds.
I would decide now whether you go LED or not - you would be better off with a negative ground for a variety of other reasons, but you may be beyond that point.
_________________
Mike - MVPeters at comcast.net
2002 MINI Cooper 'S' |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Mon Mar 14, 2022 11:16 pm Post subject: |
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| MVPeters wrote: | Yes. X = -12V from an ignition-switched source.
No. I doubt if it will work with incandescent bulbs. Check with classiccarleds.
Note: Some LEDs are polarity-sensitive so stick with classiccarleds.
I would decide now whether you go LED or not - you would be better off with a negative ground for a variety of other reasons, but you may be beyond that point. |
I thought there might be a problem. Yes I have invested in a new electronic distributor with positive earth so too far down the road to change now.
I found another flasher unit but it is 6 volt. Typical.
I shall have another look tomorrow. |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Tue Mar 15, 2022 10:31 am Post subject: |
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The good news is that I have NOT ruined my flasher/switch after all! Today I tested the switch with a 21W indicator bulb - providing the "load" as advised - and it flashed quite happily. 
All I need to do now is fit the relays the right way round for positive earth and the panel lamp should work as intended.
Fingers crossed.  |
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Ray White
Joined: 02 Dec 2014
Posts: 6318
Location: Derby
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| Posted: Tue Mar 15, 2022 8:22 pm Post subject: |
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Hoorah
Thanks to everyone here I have tested my indicators and they are working O.K.! The panel light is also working as hoped for.
Jean is so relieved she suggested opening a bottle of champers...but I wouldn't go that far. 
I would still like to know is what is the effect of using 1 amp rather than 5 amp diodes?  |
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bjacko
Joined: 28 Oct 2013
Posts: 362
Location: Melbourne Australia
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| Posted: Sat Apr 23, 2022 7:28 am Post subject: Diodes |
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| Ray, Think of a diode as a non-return valve, current as flow and voltage as pressure. at least that is what I was told when I was an apprentice aircraft fitter!! |
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ukdave2002
Joined: 23 Nov 2007
Posts: 4105
Location: South Cheshire
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| Posted: Sat Apr 23, 2022 12:31 pm Post subject: |
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| Ray White wrote: |
I would still like to know is what is the effect of using 1 amp rather than 5 amp diodes? |
Assuming the diodes are working, I can only think that the warning lamp draws such a small current that there was not enough voltage generated across the larger diode for it to conduct?
Dave |
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