Hello identifying diode

[Dr Zeus]

The smaller diode has a 04 parallel to the cathode and 02 perpendicular to the cathode.

I put a 1n4002 in the photo for reference.

What is the smaller diode equivalent to? Thank you

 

[Perry Babin]

How is it being used?

 

[Dr Zeus]

Its inside of the retractor relay box of this old car. The diode in question burned in half Cathode is Pin 14. Anode is pin 17. Nothing else is connected to these pins.

Looks like its used as part of a switch to activate the fog light relay, but only when the headlights are ON.

 

[NareshBrd]

Coil protection diode, then?
Most diodes will work.
400x series, or similar, see the current needed to choose properly.

 

[Perry Babin]

I agree with #4. It's not on a high-speed switching circuit so most any diode will work.

 

[NareshBrd]

Should not blow, check why it did...

 

[Dr Zeus]

Should not blow, check why it did...

I believe the Fog relay was bypassed and the diode could not supply amperage to the bulbs.

 

[Perry Babin]

Was the original diode working in the circuit for any length of time?

 

[Dr Zeus]

No. I found the circuit like this. The diode was blown. Second photo is from a good unit.

 

[Perry Babin]

Are you saying that this is a board that was new and it failed immediately when it was first used?

The diode and traces aren't large enough to be used for any high current circuit.

 

[Dr Zeus]

It was brought to me not working with an amp service. I’ve talked to the owner about it. Sounds like the relay was bypassed

 

[tomchr]

What are the numbers/markings on the diode that you're trying to replace?

Tom

 

[phase]

It’s likely a bean counter effort to save a couple pennies, but would be nice to know before just replacing it with a standard part.

Automotive is ruthless with cost saving, counting by the 1/10th of a penny…