temperature warning light inop on 924614A

[johnbell47]

With the key on, can you ground the sender wire, and the light comes on? If it does not, there as a power wire broken going to the light. If the light does work, the new sender is likely faulty.

with key on, grounding the sender wire does not bring the light on. the other side of the light does have 12 volts and works with a jumper wire to the sender. So. there is an open in the sender wire from the sender to the light. (evidently) this wirew also goes through a diode to the warning buzzer. They evidently buried the diode in the wiring harness. anybody know where so i can check it? I did verify that the new sender works with a light and heated it up with a heat gun, it tripped at about 230 degrees and showed continuity.

 

[Auto Doc's]

Hello J.,

The diode is likely placed inline under some black shrink take and it is blown/fractured internally from a shorted warning buzzer. Trace down the harness from the buzzer and the light, then bypass the buzzer and the diode one at a time to see if the light works when the sender is grounded.

 

[johnbell47]

Hello J.,

The diode is likely placed inline under some black shrink take and it is blown/fractured internally from a shorted warning buzzer. Trace down the harness from the buzzer and the light, then bypass the buzzer and the diode one at a time to see if the light works when the sender is grounded.

sound like a plan. The buzzer has been working. I checked the leads on it with the engine running and was showing a light on both sides, I was using a probe light, battery was dead on my meter, but I will check it in the next few days, cold in the shop right now. thank you ! if I the value of the diodes I could just run a new wirre with a diode in it over to the buzzer to see what happened, If the diode blew I would know the buzzer has gone to ground, I really don't think it has due to it worked recently. I can check it in other ways I guess, but diodes are cheep.

 

[StarTech]

Tnx for the IPL it is definitely different than the one I dl from Hustler for that model number.

IF the buzzer is working with the lead is grounded at the temp switch then the diode pack [could be two diodes tied together at the anodes] is likely good as it only prevents feedback to the oil pressure light and vice versa. Now in post #1 you said you get no alarm buzzer when the lead is grounded but the light works [I assume that what you meant to say]. Now one of the diode could open so have you tried grounding the oil pressure switch to see if the buzzer works? If it does then it is likely you have a break in the yellow/white wire. Diodes in a ground circuit seldom burns out.

Here is another question did leave the original lead connect at the light when you ran the separate wire getting the light to work? If not try that and see if the buzzer and light works. If they then this is kinda pointing to a failed splice connection and not a diode problem. If so trace the yellow/white wire to find the break.

Now if the buzzer don't work then the problem could a broken at the diode pack on the yellow wire as that is the tie in point for both sensors or any where along the yellow wire lead. A test to verify this would run a temp lead between the light ground point and test the buzzer with the pressure switch lead grounded.

I know this is a lot of testing but it will help pin where in the circuits the problem lays from there it is hand tracing that part of the circuit.

 

[StarTech]

And did you ever get the fuel gauges to work? Was it one or both?

 

[johnbell47]

Tnx for the IPL it is definitely different than the one I dl from Hustler for that model number.

IF the buzzer is working with the lead is grounded at the temp switch then the diode pack [could be two diodes tied together at the anodes] is likely good as it only prevents feedback to the oil pressure light and vice versa. Now in post #1 you said you get no alarm buzzer when the lead is grounded but the light works [I assume that what you meant to say]. Now one of the diode could open so have you tried grounding the oil pressure switch to see if the buzzer works? If it does then it is likely you have a break in the yellow/white wire. Diodes in a ground circuit seldom burns out.

Here is another question did leave the original lead connect at the light when you ran the separate wire getting the light to work? If not try that and see if the buzzer and light works. If they then this is kinda pointing to a failed splice connection and not a diode problem. If so trace the yellow/white wire to find the break.

Now if the buzzer don't work then the problem could a broken at the diode pack on the yellow wire as that is the tie in point for both sensors or any where along the yellow wire lead. A test to verify this would run a temp lead between the light ground point and test the buzzer with the pressure switch lead grounded.

I know this is a lot of testing but it will help pin where in the circuits the problem lays from there it is hand tracing that part of the circuit.

Thank you sir for the response. I am beginning to understand how this circuit works. Making sense now. I could not figger out why they put diodes in there in the first place! Hustler did a nice job on those wire looms and I hate cutting into them randomly looking for those diodes. I think I will just re run two new wires from the oil pressure and temperature sender over to the control panel put a couple of diodes in and run from them over to the buzzer. Am I correct that this wire is the ground side of the buzzer? The other side goes over to the diesel controller, not sure why but it does. I took the controller off and cleaned the terminals to it and reinstalled. (first thing I ever do on wiring is clean everything) again, thank you for your assistance, it builds my confidence considerably! One thing I have discovered it that althought I know what a diode is, that is about all I know. Looking as the many diffent types, specs, etc. leads me to ask, what value and kind of diode would you try? thanks!

 

[johnbell47]

And did you ever get the fuel gauges to work? Was it one or both?

I never got them to work, but finally realized that I don't need them. I probably won't run through two fills a year with this. I mow about 8 acres every other week. I have found that the diesels burn very little fuel. I used to mow with a Ferguson 20 that held 7 gallons of gasoline and I had to fill it twice to get it mowed, the Kubota TG 1860 diesel that I was using to mow the 2 acre yard would need fuel once a year. I think that Hustler came up with a retrofit kit for this that used a regular gauge with a double needle set up for two tanks with an hour meter built in. I have made inquires as to whether these more conventional senders would work but the guy needed to measure them and he was out of stock. Do you have knowledge about how these senders mount in the tanks? looks like they are just a push in deal with rubber washers and some kind of lube or glue maybe that comes with the kit. I think mounting senders from the bottom and upside down is a little strange and prone to leak. In every other case that I have seen the senders mount in the TOP of the tanks.

 

[StarTech]

Thank you sir for the response. I am beginning to understand how this circuit works. Making sense now. I could not figger out why they put diodes in there in the first place! Hustler did a nice job on those wire looms and I hate cutting into them randomly looking for those diodes. I think I will just re run two new wires from the oil pressure and temperature sender over to the control panel put a couple of diodes in and run from them over to the buzzer. Am I correct that this wire is the ground side of the buzzer? The other side goes over to the diesel controller, not sure why but it does. I took the controller off and cleaned the terminals to it and reinstalled. (first thing I ever do on wiring is clean everything) again, thank you for your assistance, it builds my confidence considerably! One thing I have discovered it that althought I know what a diode is, that is about all I know. Looking as the many diffent types, specs, etc. leads me to ask, what value and kind of diode would you try? thanks!

Especially since appears the harnesses are NLA. I don't opening the harnesses either sometimes it is necessary. But most harness uses split wire looms so it a matter opening a section to the wire you are looking then pierce that wire insulation with a straight pin to tap the wires inside that way there no cut wires to spliced back. Just be as insulation this old will be hard to pierce.

Yes the diodes are on the ground side. Rating will be at least 1.5x the current draw of the buzzer. I tend use 2x amp ratings just gives a good safety measure. As voltage rating you are looking a 50v or better. But do see around 0.707 forward voltage drop when forward bias, just the nature of silicon junctions. So if under 3A draw the 1N5400G with 50 PIV should handle it. But you could also use the 1N5401G [100v] or 1N5402G [200v]. All three has an initial surge current rating of 200A.

The controller is what supply the 12V to the cooling fan and buzzer if the fan is operating that shows the controller J1-N output is good. Just got to verify that there is 12v at the buzzer, one thing I think you might over looked for the buzzer.

 

[johnbell47]

Especially since appears the harnesses are NLA. I don't opening the harnesses either sometimes it is necessary. But most harness uses split wire looms so it a matter opening a section to the wire you are looking then pierce that wire insulation with a straight pin to tap the wires inside that way there no cut wires to spliced back. Just be as insulation this old will be hard to pierce.

Yes the diodes are on the ground side. Rating will be at least 1.5x the current draw of the buzzer. I tend use 2x amp ratings just gives a good safety measure. As voltage rating you are looking a 50v or better. But do see around 0.707 forward voltage drop when forward bias, just the nature of silicon junctions. So if under 3A draw the 1N5400G with 50 PIV should handle it. But you could also use the 1N5401G [100v] or 1N5402G [200v]. All three has an initial surge current rating of 200A.

The controller is what supply the 12V to the cooling fan and buzzer if the fan is operating that shows the controller J1-N output is good. Just got to verify that there is 12v at the buzzer, one thing I think you might over looked for the buzzer.

I rechecked the buzzer and it is ok. I initially just jumpered a hot and ground to it and it warbled. I know it also is triggered when you leave the key on without the motor running and it sounded when I did that. I found that it uses the oil pressure switch to tell it the motor is running or not. I found that trying to see if grounding the OP switch made it sound, it won't unless the engine IS running. At this point I am assuming I only lost the diode on the temp light wire, because the oil pressure side operates ok. What I am thinking is just re run a wire to the temp light and tag off of it to a diode to go to the buzzer. I have a diode left over from wiring my Geo Tracker to be towed behind the motorhome so I am going to try that, I do not know the rating but it handles at least two incandescent bulbs, If it blows I will know and go to one that is rated correctly. Surely, that buzzed doesn't draw that much. I thought about just buying a 10 buck back up alarm from Amazon and run a separate circuit altogether. I am sure that Hustler buzzer is pricey.

 

[StarTech]

Okay sounds you got narrowed to the area that causing the problem. Now it is just a matter of finding what in that area that has failed. Be it a bad splice, broken wire, or a failed diode. Just I knew where diode was but I have never worked on one these diesel units.