64 replies to this topic

[Tonylamb]

Interesting that in this wiring diagram the white wire from the ignition bulb does not go to the voltage stabiliser.  On my car I think it does??  this would possibly explain the problem.

 

So can I run any positive feed from the ignition, only when ignition is on to the other side of the ignition light.  Does it have to run through the voltage stabiliser.  That might be a simpler option?

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[GraemeC]

It doesn’t have to be from the voltage stabiliser. However if you have it connected to the B terminal then this is the ignition feed to the stabiliser and should be fine. The fact the lamp is illuminating also points towards it getting a 12V feed as required.

It sounds more to me like either the other side is earthed and not connected to the brown/yellow (or at least not all the way through to the alt) or your alternator is duff.

You could also check the output voltage of the alt at its connections, rather than at the battery - just in case there is an issue somewhere else in the wiring. You should be able to remove the back of the plug to get a meter onto the terminals)

[Tonylamb]

So I've taken the dash out and the white wire at B on the voltage stabiliser is live as is the white wire at the red ignition light. I ran a wire from the end of the brown and white at the alternator to the bulb and checked the continuity which is fine so the brown and yellow wire is good from the alternator to the bulb. The bulb only comes on with the alternator plug connected to the alternator. But if you start the engine the ignition light still stays on??? The bulb is definately not earthed I pulled it clear of the speedo and it is a plastic surrounded bulb holder so it can't be earthed. Tomorrow i will try and take the back of the alternator plug and see if the alternator is actually charging. Its a brand new alt from mini spares but I suppose its possible that it could be faulty.

I'm back to thinking its somewhere else in the wiring that is the problem. But the light should go out if the alt is charging.

[Tonylamb]

so a discovery this evening. I thought I'd re check the continuity of the wires coming out of the alternator. The large brown and brown and blue are fine at the solenoid point. While I was checking the continuity of the brown and yellow wire I accidentally touched the back of the speedo and the meter beeped. So the brown and yellow wire is presumably earthed somehow. Again presumably in all the wiring into the central dash. My presumption is that the brown and yellow wire should be live not earthed.

I could back track and take all the wires apart into the dash or I'm thinking I can run a completely new wire from the alternator plug to the bulb and use the existing live white wire or a new one from the voltage stabiliser. Because presumably somehow the brown and yellow is earthed somewhere, I don't know how.

Does that make sense and would it work

[GraemeC]

Was the brown/yellow connected to the alt at the time (I’m assuming the engine was off) if so then yes, you will have continuity to ground through the alt - that’s what makes the lamp light.

If it was disconnected from the alt then you do have a short somewhere on that wire.

[Tonylamb]

I shoved the multimeter red in the disconnected plug at the brown and yellow. If you then touch the back of the speedo you get a signal. So somehow, somewhere between the alt plug and the speedo the wire must be earthed. It might just be easier to run a new wire from the alt to the lamp. As that would still be effective. Tonight I'll take a look and see where the brown and yellow connects to the new central speedo loom. Really appreciate your help and patience this is what the forum is all about.

[Tonylamb]

So it seems like the problem was somewhere in the new short loom to the centre console. I bypassed the wire from the ignition bulb to the old loom end. Light on start engine light off. Didnt have a chance to test the charging but assume that works to. Thanks for the help.

[GraemeC]

I would check that loom thoroughly then - if there is some short or mis-connection in there who knows what else may be wrong. If it is cut wires there is a risk of a short circuit causing something nasty.

Glad you got it sorted though - it’s certainly tried your patience!

Edited by GraemeC, 11 January 2019 - 01:20 PM.

[Tonylamb]

everything else seems to be working fine although the fuel gauge doesn't seem to be working.  that said there isn't much fuel in the tank maybe a gallon at most.  I've got the centre dash out so will double check all the connections.  I did find a blue and green wire that had become disconnected so I've joined that back up again.  I'm going to start it over the weekend and check all the wiring and that the alternator is actually charging.  I'll be able to let the engine heat up and check the temperature gauge etc which is all on this new loom.  The oil light goes out and the oil gauge is capillary.  I can check the fuel gauge at the same time.  I've rebuilt the car from scratch pretty much including all the wiring.  I've been careful but its not surprising that the odd small issue surfaces when you are using new looms that are non original and different parts from different years.  Fortunately no smoking wires of fires, fingers crossed.

 

Thanks again for the help

[Tonylamb]

14.2 v at the battery with the engine running but no fuel or temp gauge readings at all. I'm a bit suspicious of the voltage stabaliser because the terminal with the white wire is loose. I'm trying to find some narrative on testing the voltage stabiliser. I'm going to check the wiring of the fuel gauge and the temp gauge sender as well. I understand you need to have the right temp gauge sender with the right gauge, they aren't universal.

[Tonylamb]

I'm known for my patience in our house but the wiring on the mini is testing it. Neither the petrol gauge or the temp gauge are working.

I've tested the voltage stabiliser. I have 12v at B and 10.12v at I. the green wires to both the petrol and Temp gauge both read the stabilised 10.12v which I assume are correct. So the power to the two gauges is fine???

on the temp gauge I checked the continuity of the blue and green wire from the sender to the gauge. Its fine. I grounded the sender wire which should in theory make the gauge go to max? I then swapped over the wires on the gauge and grounded it again? still nothing. So its possible that they gauge itself is non functioning. How do I check the gauge itself?

On the fuel gauge I have no idea if the sender is working but presumably I can ground that as well to get a responsee?

Help please before I go a bit mental LOL.

[GraemeC]

Yes you can ground the fuel sender wire.

The only way you can test the gauge is to ground out the terminal on the back of it that the blue/green connects to.

[Tonylamb]

so one side to 12v and ground out the sender side?

did the 10.12v from the stabiliser seem OK to you? I read its supposed to be 10v so that seemed fine.

When I ground out the sensor the gauge doesn't move at all. Doesn't make much sense?

appreciate the answers to the endless questions. I'm so close to getting the car on the road so its frustrating as hell.

[Tonylamb]

intersting i took the gauge out of the car and just connected to an old battery I had laying arouund. It was only producing 10v. The gauge doesn't work if you hold it the right way up but if you tip it on its side it does. So I suspect the actual gauge might be faulty. There is no real way of testing them with the equipment that I have. I'll try a different gauge as I have a few but may have to buy a nice smiths one.

[Tonylamb]

I'll adress the fuel gauge seperately because that might be the sender. the voltage stabiliser is working correctly and producing the right voltage for the gauges.