blowing mpem fuse

[s_hartman]

i got a 96 spx 717 from a friend to work on and when i put a new battery in one of the fuses on the mpem blew if your looking at the mpem with the fuses at the bottom it was the left one. when i unplug he magneto connection from the engine it does not blow the fuse. does this mean that the mag is shorted or is there somthing else i should be looking at. and maybe if someone could let me know what the proper ohm readings should be from the mag that may be helpful in determining if the mag is fried or shorted. thanks

 

[timmyboy76]

good job, disect'n the prob, chief. If it stopped pop'n when you disconnected the mag plug, then you have a bad wire/s or metal shavings in the stator area, ground'n out the system...:cheers:

 

[s_hartman]

ok thanks for the reply ill take the mag cover off to see what ive got any other suggestions would be helpful too

 

[s_hartman]

does anybody know what the correct ohms readong should be for the 96 spx i have the whole mag unit off and did some testing there are four wires 1 black, 1 black w/red, 1 yellow and 1 yellow w/black. the black one is ground the black w/ red is for the charger coil? the two ohm out to 60 which i found to be within specs. however the yellow and yellow w/black test short ie 0 ohms these are for the lighting coil. shouldnt there be somthing here not short ive read a few different readings but there isnt a thread that has my setup exactly. any help would be helpful. thanks

 

[timmyboy76]

hartman...check the "pins" inside plug, might be corroded. Cant help on "ohm"spec, but if it is bad, I have both, the generating and ignition coils...new.

 

[s_hartman]

i have the whole thing out the pins and wire are good its just the ohms test doesnt seem right i mean there are basicly ciols so there should be resistance there esp when thereare three of them i series they should all add up to somthing not shorted right?

 

[s_hartman]

update: well everything checkout ok with the mag so know i gues its the mpem i did test the 5A fuse holder and one side is shorted to ground so i guess thats my answer

 

[s_hartman]

this page should help anybody with mpem problems thank timmyboy for the lead

 

[All Things Custom]

This is a shorted MPEM.

The reason it stops blowing when the mag is unhooked is because your mpem is grounded through the stator.

this is a common problem I repair however if there is larger than a (SAY) 10 amp fuse put in there it will destroy the MPEM because most circuits in the MPEM are 15 amps.

You have yourself a doorstop now, might as well start searching for a used MPEM.

There is nothing wrong with the stator, it is caused from jumpstarting the ski or running with a low battery.

Mike

 

[s_hartman]

:cheers:

This is a shorted MPEM.

The reason it stops blowing when the mag is unhooked is because your mpem is grounded through the stator.

this is a common problem I repair however if there is larger than a (SAY) 10 amp fuse put in there it will destroy the MPEM because most circuits in the MPEM are 15 amps.

You have yourself a doorstop now, might as well start searching for a used MPEM.

There is nothing wrong with the stator, it is caused from jumpstarting the ski or running with a low battery.

Mike

Thanks Mike Everything is as you said! and i have now begun my search for a new mpem

:cheers: