Craftsman PGT9000 Briggs 28hp not running correctly
- Thread starter oakdale81
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RandyT
Elite Member
I know some people have come up with a part number of the diode that they picked up at Radio Shack for cheap. As a dealer it is easier to just replace the kill wire harness
RandyT
Elite Member
Will need model number off of the engine itself to look up parts. Could be on the blower housing or next to the oil filter if Vanguard engine, or on the valve cover if intek type engine.
Model number will be in the format of XXXXXX XXXX XX normally will actually say model type and code on the tag or on the valve cover.
Model number will be in the format of XXXXXX XXXX XX normally will actually say model type and code on the tag or on the valve cover.
RandyT
Elite Member
The engine family is the EPA certification number and doesn't mean anything to anybody other than maybe the EPA. The Vanguard engine normally has a metal tag riveted to either the blower housing or in the area around the oil filter. the other V twin briggs engines should be stamped into the valve cover. The craftsman model number IPL doesn't list the breakdown for the engine.
Grumpycat
Veteran Member
Am not sure what meter you are using, what mode, or how you are using the test leads.
Ideally a "diode mode" should be used. It should indicate the conduction voltage through the diode. But the thing I fear you didn't understand is that a diode is only supposed to conduct in one direction. The question is whether yours are conducting in one direction, two directions, or neither.
Another concern is how your meter indicated "infinity". Am guessing it is "1L" or something like that? It will be whatever is displayed when the leads are not touching anything.
What you need to do is disconnect the harness so at least one end of each diode is connected to nothing. Then measure with your meter across each diode, both ways. Red on one side, black on other, then vice versa. One direction should conduct, the other not.
Diodes are almost always marked with a part number. Will also have a white stripe on one end. That is important to replace diode with white stripe oriented correctly.
Am guessing the diode will be of the 1N400x family, where x = 1 through 7. This is a very common 1 amp power diode. The last number indicates the reverse voltage rating. 1N4001 is rated 50V and probably good enough. Whatever you have can be replaced by anything with a higher voltage rating. So if it is a 1N4002 and Radio Shack only has 1N4007 then buy the 1N4007 and be happy!
1N4x general-purpose diodes - Wikipedia
RandyT
Elite Member
It looks like Briggs is only offering complete wiring harnesses for that engine. The harness part number various depending on engine configuration Like with or without oil pressure switch.
Thanks for the additional info. I do understand how a diode works, it is allowing voltage both ways. I work in IT these days and came from a previous life of recreational powersports but diodes were not found in harnesses so this was something new for me. Also I had the harness completely disconnected while testing. The forums are a great source for people even when they have years of experience. The 4 local shops that work on these had no answers, which I kind of figured as when they have serious electrical issues come in that they cant figure out I get calls to come take a look at stuff. I appreciate the help and the extra info on the diodes. We dont replace them generally, eqiupment generally is old by the time they fail so it gets replaced in my line of work so I had forgotten what I learned about the diode numbers in my schooling.
