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DYT 4000 blown fuse

Posted by Rick222 MA (My Page) on
Thu, Jun 13, 13 at 11:05

First I replaced battery tried to start tractor would not start. jumped the starter tractor ran until I engaged clutch ,blow fuse. found I hooked battery up backwards (Stupid Me) I replaced fuse engaged clutch all ran fine .next couple of time I mowed with it, the fuse would blow in the middle of mowing for no reason. I would replace fuse start back up and finish mowing. this happen for a couple of mowing time. This week replacing the fuse didn't work. So this is what I tried. disconnected clutch engage clutch blow fuse. reconnected clutch disconnected rectifier engaged clutch blades and mower ran fine. Replaced rectifier with new engaged clutch blow fuse. disconnected yellow and red wires and left black wire connected to the screw on rectifier engaged clutch blow fuse. disconnected all wire on rectifier engaged clutch blade turn and tractor ran with meter on dash reading 5 to the left of zero. Questions are 1) What is the rectifier for? 2)where does the wire connected to the screw go? 3) could that be shorted out? I thought it was a ground wire. 4)any ideas what is wrong ? 5)if it is a short how do you find a short? 6)Can you use a muti meter?
Thanks


Follow-Up Postings:

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RE: DYT 4000 blown fuse

Well, the first step in getting an idea would be for you to post a valid, technical model number. DYT 4000 is only a marketing model description. Actual DYT 4000s vary in many respects over a range of production years, and knowing the "model year" is no help either. Sears does not have support based on year model. Technical model # only.
The Craftsman technical model number should be on a decal on the body beneath the tilting seat. You should also include model and type numbers found on the engine as well.
Hopefully, knowing the actual technical model number will permit some of us to view an electrical schematic online to see what else might have occurred because you connected the battery in reverse polarity.
To answer one of your questions, the rectifier converts AC from the alternator output into DC, which is the only type of current useful to the battery.
Other answers pending your posting of the critical numbers requested.


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RE: DYT 4000 blown fuse

I know the numbers are needed but I'm at work. I called home with no luck to get model number. I do have engine # it is 31P7770348E1.I've been looking on the net and when I get home I will start testing diode, alternator and what looks like to me as the grounding wire on the screw for short. I also tested the rectifier with a muti-meter both new and old are fine. I have just 2 wire coming out of the rectifier red to equipment yellow to stator or alternator and 1 connected to the screw that holds the rectifier to the engine. So I will find the number when I get home. this is the first time I ever saw this site. It looks like it could be very helpful.


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RE: DYT 4000 blown fuse

this the # 917.275640


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RE: DYT 4000 blown fuse

Your post is very hard to understand-

disconnected clutch engage clutch blow fuse????

What rectifier are you testing?
Your charging system has a Voltage Regulator.

Please use paragraphs!


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RE: DYT 4000 blown fuse

Answer these.
All the fuse blowing began after you ran the engine (and engaged the PTO clutch with the battery installed backward???
The fuse only blows when you have the PTO clutch engaged???
If the PTO clutch wiring is not connected, the fuse does not blow???
The voltage regulator/rectifier you bought is Briggs part number 794360???


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RE: DYT 4000 blown fuse

My voltage regulator/rectifier converts AC from the Alternator/Stator output into DC. I guess I gave to much info, lets try this again. mowie questions fuse blowing begain when I connected the battery in reverse polarity. I thought it was the switch or starter , so I hot wire the tractor to get it started, the starter was fine and it ran until I engaged the PTO.When I replaced fuse every thing work, was able to mow for the next couple of weeks. Then the fuse would blow in the middle of mowing with the PTO engaged.I would replace fuse and every thing work fine this happen for couple of weeks. Now everytime I engage PTO fuse blows . YES the fuse only blows when I engage the clutch. With the PTO clutch wiring disconnected the fuse still blows.only when voltage regulator is completely disconnected and clutch connected the fuse does not blow and mower and blade work fine.No it is a TRANSPO MESBR1546 witch is the same as a 794360. I also checked both and they are fine


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RE: DYT 4000 blown fuse

Almost like trying to unravel a plate of spaghetti (in regard to recreating a scenario in my mind that might fit these details).
I guess I should begin a sort of rambling explanation of some things you have mentioned, just to get those out of the way.
The small black wire mentioned is certainly a grounded wire (if it was originally connected to the regulator mounting screw).
Being a "grounded circuit", it can't short to ground because it already is a ground, (if it is attached to a ground).
The meter on the dash that shows you "5 amps discharge" with regulator disconnected.............is the ammeter.
The fact that it shows 5 amps discharge is reflecting the absence of charging current being furnished by the charging system when the alternator is "off line" (regulator disconnected) BUT WITH the PTO clutch load being applied to the battery. In other words, the ammeter is telling you that the battery is discharging at a 5 amp rate because of the combined load of the PTO clutch and the carburetor solenoid valve. A 5 amp load from these 2 items is about right for normally functioning components of this size/class.

Where, exactly, are you disconnecting the PTO clutch wiring when you do that?? Are you separating them down at the PTO clutch? or are you disconnecting the PTO switch harness? (I am guessing down at the clutch)

You stated in your post today that you "hot wire the tractor to get it started".
How did you accomplish said "hot wire"??

At this point, the questions about where you are disconnecting the PTO clutch and how you did your hot wire cranking...........may be key to visualizing what has happened to the electrical system.


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RE: DYT 4000 blown fuse

when I connected the battery the right way, it still would not start. So I use jumper cable connected to the correct sides of the battery and connected black cable to frame and touched red to starter post with the key in run position. I disconnected the clutch down at the clutch .


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RE: DYT 4000 blown fuse

Rick, at this point, I suggest you get under the tractor and try to trace out the wiring leads on the CHASSIS portion of the PTO clutch circuit.
There may be a place in that wiring which has chafed or burned through, that touches a ground.
If you do not find any sort of bare spot in the hot wire leading to the PTO clutch, do the following.
Disconnect the PTO clutch wiring at the PTO clutch (like you have been doing) and tie or tape the loose ends out of the way.
Next, operate the tractor in a normal fashion WITH THE PTO SWITCH ENGAGED and the voltage regulator connected. This means to actually drive the tractor around as if you were mowing, but without blades. The jostling and vibration may play a role in what happens.
If the fuse still blows, you likely have a short in the hot wire that serves the PTO clutch, OR.............the Clutch "snubber diode" has become shorted (or intermittently shorting) and thereby causing a short to appear at random to blow the fuse.
Perhaps someone else on this board can inform of which component in the wiring is actually the snubber diode, the parts breakdown does not identify it as such, but it is in there.
Some older threads dealt with issues of snubber diodes becoming damaged but I don't remember all the details of those (even though I participated in some of them).


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RE: DYT 4000 snubber diode

OK, I dug this out using a search of the archives.

Here is a link that might be useful: snub the discussion, and the voltage spike


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RE: DYT 4000 blown fuse

I can't operate the tractor with PTO engage and clutch wire disconnected. blows fuse

Only if I disconnect the regulator and leave clutch connected then everything runs fine. Blades spin and engine run fine. I just draw 5 amps from the battery.

It also blows fuses if I don't disconnect the mounting screw wire on the regulator.

What does the regulator do when I engage the PTO?

Could there be a short in the red wire from the regulator to the PTO switch?

I will try testing regulator, alternator and check wires for shorts when I get home.

I looked at some of your link, good ideas. I will look at them more if I don't get any results from testing.

will also look to see if I can find that diode.
Thanks


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RE: DYT 4000 blown fuse

TEST
Alternator 44 VAC
Regulator 9 amps DC to start the fell to 2.4 amps DC

Warner clutch test 3.5 ohms.

should be 2.4 to 2.9 ohms

Clutch needs to be replaced

Is this test reliable?

There is no diode, it must be inside the clutch.

This screw up is going to cost me.

when I replace the clutch I will give a up date

Thanks to all


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RE: DYT 4000 blown fuse

I don't know how to explain the 44 VAC you have posted except that your multi-meter may be a bit "off". Briggs specs for the 9 amp regulated charging system is given as 40 VAC max at 3,600 RPM. Otherwise, the performance of the charging components is right where it should be and if you had run the engine longer the amp rate would have probably decreased even a bit more as the battery attained a more complete charge.
The tests on the clutch (if done correctly) are the best proof of condition you can have.
As I stated in a previous post, I do not know WHERE the snubber diode is situated (physically).
I do know that most automotive circuits where a large coil of wire is employed in electromagnetic tasks.........a snubber diode is usually included to shunt the self-induced voltage spike that occurs when the power to the coil is turned off, harmlessly to ground.
I also know that diodes fail in different ways when subjected to current values higher than their capacity, especially when they are faced with a really large surge of inverse voltage where the amp load is also of a high value.
Sometimes a diode will simply become OPEN, and if it is a PTO snubber diode in the spotlight, the most obvious problem you would notice would be your tractor might begin eating PTO switches like popcorn.
Or.......the diode might transform into a shorted (or semi-shorted) condition..........and this could lead to blowing fuses.
BUT..................you seem to have stated that the fuse will continue to blow with the PTO clutch DISCONNECTED. That (to me) implies that any shorted snubber diode would have to be in the wiring on the CHASSIS side of the PTO clutch wiring (if in fact a shorted snubber diode is causing this.
If the snubber diode is integral to the PTO clutch......unplugging the clutch wiring would isolate that and the fuse blowing should stop.

You haven't done anything like replacing wires or splices on the tractor, have you??
Can you physically trace the path of the black wire referred to as connecting with a screw to the regulator mounting?
Your budget must be highly organized if you know you will have to sacrifice "a date" in order to afford a buying new clutch. :^)
HEY FORUM ADMINISTRATORS! Could we get some "smilies" added to the forum tools please??

This post was edited by mownie on Sat, Jun 15, 13 at 11:24


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RE: DYT 4000 blown fuse

I'm not the best at typing
and that is a update not a date, I been trying to race my internet link. it keeps failing ,for the last couple of day.

I did trace the black wire, it does go to ground. I will check for that diode some more. I agree when I disconnect the clutch it should stop blowing fuses but it doesn't.

I also confused about why it still blows fuses when I disconnect the red and green connection on the regulator and leave the black ground wire.

I think I will try that clutch test again with my muti-meter from work to make sure

I hate wiring problems.

Thanks for the help


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RE: DYT 4000 blown fuse

Diodes on many of these are above where the clutch harness meets the pan. Reversing the cables can blow this diode and I'm wondering how the charging system really fared.


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RE: DYT 4000 blown fuse

Found diode was engine side of clutch plug.
diode was burnt. Thanks to Radio Shack was able to replace diode.

engaged PTO all's work well.

know why it would blow the fuse when clutch connection was disconnected and regulator was connected.

When diode is burnt it makes a direct connection to the other wire before the plug on engine side.

THANKS THANKS

I will not have to hear my loving wife tell me. If you didn't hook the battery up backwards you wouldn't be having these problem. tell me something I didn't know.

Thanks again


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RE: DYT 4000 blown fuse

Whew! I'll help you breathe a big sigh of relief.
You are exactly right about the why and the location of the snubber diode constituting a short.


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