4 replies to this topic

[ledet]

The fuel and temp gauges on my 1992 carb Cooper haven't been working properly, so I tried replacing the voltage regulator using this guide: http://www.theminifo...tage-regulator/

 

I followed it step by step, but when I put the cluster back in and turned the ignition on, the lights in the gauges came on and I heard a tiny click.  Then - smoke started coming out from underneath the gauges. 

 

I removed the cluster again, and it smelled like the smoke had come from the new voltage regulator.

 

I'm reluctant to put it back in and check again (I don't want to light my Mini on fire...), but I guess I blew the new voltage regulator? Does anyone have any idea why this would happen? What might I have done wrong? And I assume that when smoke comes out of the voltage regulator it means it's dead and I have to buy another one. Right?

 

 

Thanks. 

 

/Andreas

[dklawson]

If you connect any of the regulator leads wrong the chip will rapidly overheat and fail as you describe.  I know you said you followed Stormin's instructions but it is easy to confuse what is "in" and "out" on these chips unless you have a schematic with isometric views of the chip to keep the orientation clear.

 

You can also experience failure with these chips if you have connected the output to something that provides a short directly to earth.  However, all these failures usually take a few moments, the failure is not instant.

 

The chips are relatively inexpensive.  Assume this one is dead and try another.  When soldering to the chips leads, use pliers or hemostats to hold the chip lead and act as a heat sink.  You do not want to put too much heat into the chip during the soldering process.

[KernowCooper]

Smoke is never a good sign from any electrical component, always the component is damaged

[ledet]

Thanks a lot for the answers. I'll try to find a new chip tomorrow and hopefully I'll do it probably this time. 

Another question regarding Stormin's guide though - I don't really get the step where I'm supposed to block a contact point on the gauge (pics 3 and 4). Am I correct in assuming that I should just cover the brass parts with electrical tape and that's it? Am I supposed to undo the brass nut as well? I don't really see the purpose of just covering it with tape, current will still flow underneath the tape, so what difference does it make? 

Edited by ledet, 24 June 2015 - 09:09 PM.

[dklawson]

I don't really get the step where I'm supposed to block a contact point on the gauge (pics 3 and 4). 

 

Sorry, the following may be a bit wordy but I will try to be brief.

 

The original electromechanical voltage stabilizer works by heating a bimetallic spring element that holds a pair of electrical contacts together.  When the bimetallic strip heats it deflects and opens the points.  Rapid opening and closing of the points chops the voltage into an "average" 10V output used to power the gauges.  

 

When you are using Stormin's workaround you don't want to be using the old electromechanical stabilizer AND the new chip.  The tape isn't just wrapped around the old contact points, it is placed BETWEEN the points to insulate them from each other.  The tape between the points disables the old electromechanical stabilizer.  The additional tape around the outside is there to keep the first piece of tape in place between the points.