how to solder in a diode

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72ScampTramp

72ScampTramp

Scamp Tramp
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Working with my wiring for ignition MSD. Was doing some reading and some recommend soldering in a diode it the 12v small red wire...



How do you put it in? Assuming one end of wire soldered in. And the other end of wire soldered to the other end of the diode. The one that came with my box looks similar to this. I learn well via You Tube but couldnt find a good video duplicating what i need.
 

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Not sure why you need it.........but. the band on one end is called the cathode. If you look up a generic diagram, the band matches to the end opposite the arrow

like so, the band would be in the right hand end of this diode

Diode_symbol.svg.png


Conventional electron current flow is thought of from negative to positive, so current goes AGAINST the arrow.

what this all boils down to is, you would wire this so the band is toward the MSD box, the unbanded end towards the power supply voltage
 
they only allow current to flow one way --->

so if you hook things up backwards you cant fry the msd

it's just a safeguard i guess
 
I guess the big question is, "who told you" you need a diode and "what was the reasoning?"

Now there can be good reasons for using an isolation diode. One example is my old landcruiser. This had a Chev steering column but Mopar power so I didn't have the Mopar ignition switch with the infamous "ign2" circuit, but I NEEDED a resistor bypass circuit, so I just wired a diode from the start terminal on the switch over to the coil + terminal.
 
I've always heard it recommended that you use a "heat sink" alligator clip on the wire as you're soldering also, to soak up some heat from the wire, so as not to overheat the diode.

Heatsink-In-Use.jpg
 
trapster said:
it will also drop the voltage slightly, and this may reduce performance.
Click to expand...

The "small red" is a switching line, not power supply. It might actually fire a relay for all I know.
 
67Dart273 said:
I guess the big question is, "who told you" you need a diode and "what was the reasoning?"

Now there can be good reasons for using an isolation diode. One example is my old landcruiser. This had a Chev steering column but Mopar power so I didn't have the Mopar ignition switch with the infamous "ign2" circuit, but I NEEDED a resistor bypass circuit, so I just wired a diode from the start terminal on the switch over to the coil + terminal.
Click to expand...



Thanks for the reply. I was reading on some forums about MSD. A fella mentinoned that his AMP meter bounced all over the place and when i installed the diode it went away. My amp meter also does this so while i was working and rewiring i figured I would put it in.
 
I'm not sure I understand how that would be the cause, the effect, or the cure, LOL
 
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