97 GSI 5a Fuse

[GGuillot]

When do get to the diode, you'll need to at least clip one end of a diode from the board to check it. Checking it still soldered to both points won't work, you'll get an inaccurate 'shorted' indication. Clip one end then check. If it beeps, it fails. On the fuse slot, with the fuse out, one side will be hot (voltage) and the other not.

 

[kmarts]

When do get to the diode, you'll need to at least clip one end of a diode from the board to check it. Checking it still soldered to both points won't work, you'll get an inaccurate 'shorted' indication. Clip one end then check. If it beeps, it fails. On the fuse slot, with the fuse out, one side will be hot (voltage) and the other not.

if his meter actually has a diode mode he can test it without cutting. diode mode will measure the voltage drop across the component.

 

[cj3737]

It does have diode mode.. just looked up the manual. Southwire Lowes special. Never really used it for more than looking for hot wires in my house... I love learning new things!!

 

[kmarts]

It does have diode mode.. just looked up the manual. Southwire Lowes special. Never really used it for more than looking for hot wires in my house... I love learning new things!!

just remember to test in both directions, if the diode drops voltage in reverse its shot.

 

[cj3737]

just remember to test in both directions, if the diode drops voltage in reverse its shot.

When i get home I'm gonna mess around with it and test some good and bad fuses. My brain needs to know how it works before itll sink in. Thanks to both you guys!

 

[cj3737]

@GGuillot @kmarts
Just thought of something else... Was looking thru the stator continuity test and I think I did that while back just for fun.. I checked the yl to yl-bk wires and didnt get a reading.. checked the bk to bk rd wires and got something like 55 ohms. Not quite sure if I did it correctly but I just found what the readings should be for my stator. Bk wires look decent but the yl wires shouldve given me something around .05-.6 ohm.. Before I dig any further into my mpem, should I jump down this rabbit hole for a quick adventure?? Is there also a static test for the rectifier?

 

[GGuillot]

@GGuillot @kmarts
Just thought of something else... Was looking thru the stator continuity test and I think I did that while back just for fun.. I checked the yl to yl-bk wires and didnt get a reading.. checked the bk to bk rd wires and got something like 55 ohms. Not quite sure if I did it correctly but I just found what the readings should be for my stator. Bk wires look decent but the yl wires shouldve given me something around .05-.6 ohm.. Before I dig any further into my mpem, should I jump down this rabbit hole for a quick adventure?? Is there also a static test for the rectifier?

I'd compare it to another known good one, maybe someone on here could verify for you. Though a little different stator, when I get home I'll try and check the GTX and see what I get.

 

[cj3737]

I'd compare it to another known good one, maybe someone on here could verify for you. Though a little different stator, when I get home I'll try and check the GTX and see what I get.

Test results...

Good fuse. Beep
Bad fuse no beep no reading

97 gsi stator
Bk to bk rd no beep but 62 ohm
Yl to yl bk beep and .04 to .07
Tested spades on mpem- pin 1-24 to 1-25 get 198 ohms. Nothing on connector 2 at all between the spades

97 gts stator (machine runs)
Same readings as gsi

97 gs (non running flood damage in stator housing)
Bk to bk rd 62 ohms no beep
Yl to yl bk nothing at all. I suspect this one is shot because of water intrusion

Also tested gsi and gs rectifier. Only beep came from the red to yl test... all others showed nothing.

The test page I found shows the bk to bk rd should be 40-70 ohms so that's good on all 3 machines. Yl to yl bk should read .05-.6 ohms... I'm sitting at .04. Max shows a spike to .07

 

[GGuillot]

Test results...

Good fuse. Beep
Bad fuse no beep no reading

97 gsi stator
Bk to bk rd no beep but 62 ohm
Yl to yl bk beep and .04 to .07
Tested spades on mpem- pin 1-24 to 1-25 get 198 ohms. Nothing on connector 2 at all between the spades

97 gts stator (machine runs)
Same readings as gsi

97 gs (non running flood damage in stator housing)
Bk to bk rd 62 ohms no beep
Yl to yl bk nothing at all. I suspect this one is shot because of water intrusion

Also tested gsi and gs rectifier. Only beep came from the red to yl test... all others showed nothing.

The test page I found shows the bk to bk rd should be 40-70 ohms so that's good on all 3 machines. Yl to yl bk should read .05-.6 ohms... I'm sitting at .04. Max shows a spike to .07

So looks like you're going down that rat hole on the MPEM. I bet that diode in the MPEM holds an answer to a fix, I think you've narrowed it down at this point.

 

[cj3737]

So looks like you're going down that rat hole on the MPEM. I bet that diode in the MPEM holds an answer to a fix, I think you've narrowed it down at this point.

Yep. Should I be concerned with the low ohms on the yellow wires?

 

[cj3737]

Nevermind... was reading the yellow wires reading wrong... its .4 not .04...so those are good. I am missing the little orange spacer in that plug so my wires are a little loose in there

 

[cj3737]

So looks like you're going down that rat hole on the MPEM. I bet that diode in the MPEM holds an answer to a fix, I think you've narrowed it down at this point.

Started digging and I'll m at this point. I'm at something but it doesnt look like pix of the other gsi mpem I found. Gonna work around it a bit more. Very slow going...

 

[cj3737]

@GGuillot Finally got both ends showing... I did test it and I am getting the beep on the meter like it's a good circuit... gonna keep digging until I get enuf room to clip it out but I may stop until the new diodes get here..

 

[GGuillot]

Tedious work....once you clip it and if you get low resistance in both directions (short) or beep, it's bad.

 

[cj3737]

Dug out enuf room to clip one end... getting a tone going both directions. I'll prolly have to dig a bit more to have room to resolder...

 

[cj3737]

Looks like my diodes will be here tomorrow. If I get a new one in and the 5a blows, what's my next path?

 

[GGuillot]

Looks like my diodes will be here tomorrow. If I get a new one in and the 5a blows, what's my next path?[/QUOTE

I think if the diode really is bad, and it seems to be, and you'll know when you test your new one against it that it was a single point of failure. The 5A blowing is protecting the MPEM from further damage with other electronic components.

One path at a time, anxious for you to see if it fixes it, gives hope to those on here having a problem like yours. Just think, you'll be avoiding the search for $300+ MPEM for a few bucks and a lot of patience.

 

[cj3737]

I am really hoping this is the fix. Im not sure what the previous owner actually did but I did find a blown fuse in the ebox when I first opened it up. Hoping they didnt just throw a bunch of differnt size fuses all over to bypass and end up frying the whole circuit board.... If this works, Im going to make a how to video to hopefully help the masses down this path.

 

[cj3737]

@GGuillot new diodes are in but before I install, which way does the current flow on the board? The bad one has an arrow pointing north. The new ones also have the arrow pointing north for direction of flow but the numbering would be upside down. Really dont wanna screw this install up

 

[GGuillot]

@GGuillot new diodes are in but before I install, which way does the current flow on the board? The bad one has an arrow pointing north. The new ones also have the arrow pointing north for direction of flow but the numbering would be upside down. Really dont wanna screw this install up

I think @kmarts above explains the arrow and band representation, I'd have to look it up and do an assessment. Worst case if you install it wrong it'll blow the fuse again and probably fry the diode. I hope you got a few just incase. A few diodes and fuses that is...

 

[kmarts]

@GGuillot new diodes are in but before I install, which way does the current flow on the board? The bad one has an arrow pointing north. The new ones also have the arrow pointing north for direction of flow but the numbering would be upside down. Really dont wanna screw this install up

Looking at the picture i can see that the cathode (arrow) is pointing 'north' like you say. Ignore the numbering on your replacements. The band/arrow on a diode is so you know how to install it, current will only flow one way through it.

 

[cj3737]

Looking at the picture i can see that the cathode (arrow) is pointing 'north' like you say. Ignore the numbering on your replacements. The band/arrow on a diode is so you know how to install it, current will only flow one way through it.

Excellent.. I will install later today and see if I can breathe some life back into this beauty.. I do have plenty of diodes and fuses should something go awry...

 

[GGuillot]

I am really hoping this is the fix. Im not sure what the previous owner actually did but I did find a blown fuse in the ebox when I first opened it up. Hoping they didnt just throw a bunch of differnt size fuses all over to bypass and end up frying the whole circuit board.... If this works, Im going to make a how to video to hopefully help the masses down this path.

Maybe the previous PO tried to jump start it off a vehicle....sending excessive voltage and spikes of current going to the MPEM. Yeah, that would be bad to start putting in higher amp fuses to make a situation worse.

 

[cj3737]

Maybe the previous PO tried to jump start it off a vehicle....sending excessive voltage and spikes of current going to the MPEM. Yeah, that would be bad to start putting in higher amp fuses to make a situation worse.

Yeah... thats why im pretty nervous about this fix. Im hoping if they did that, the diode fail safes the system by killing the fuse...

 

[GGuillot]

Yeah... thats why im pretty nervous about this fix. Im hoping if they did that, the diode fail safes the system by killing the fuse...

Let's hope the diode 'is' the fail safe and single point of failure....you'll soon find out, put up a pic soon...we're anxiously awaited results from charted waters few have ventured into...