351w fastback said:
i just got done soldering it on. i dont think i overheated it but if i did, how can i tell? the diode used in the diagram was discontinued at radio shack so i used a 1n5404 instead. thanks for the help
It's probably just fine. It's a Silicon diode and they are fairly forgiving.
I checked the specs on the one you substituted, It's fine.
The original is the 1000 volt model, the one you substituted is only good for 400V. LOL!
You can tell whether it is good by checking the resistance with either a cheap voltmeter, or a real expensive one. It needs to be a cheap because the cheap ones supply a significant amount of current to measure the resistance. The real expensive ones ($150.) have a special position for measuring diodes.
If the diode is good it will read "open" (nearly infinite ohms, at least megohms) in one direction, and very low in the other.
But you would have to disconnect one end of the diode before measuring it. (otherwise you would just be measuring the motor winding resistance)
Unless there is something obviously wrong, it's not necessary.
The effect on your circuit if the diode is shorted will be that the motor circuit will draw current but won't run, or possibly, will blow a fuse. If the diode is "open", the danger is that the relay may stick closed or simply wear out quickly. (relay points arc when opening and closing because there is no place for the back EMF to go when the relay contact are open..) In either case you will know somethings wrong.
Roy.