1989 FC Dash buzzer wont shut off

[GregOConnor]

Trying to stop an alarm buzzer from sounding. '89FC has an alarm buzzer that sounds when the engine is on. I guess the FC is an 88 1989 300 hp cat 3208 model. The alarm stopped sounding several times, once in a parking lot at 5 mph after hitting a speed bump it stopped but then restarted while backing up a driveway. I note that there were a bunch of hacks under the dash that I reconnected and cleaned up so I may have reattached a wire to a control that had the issue or it is an entirely new issue. I plan to go to San Diego this week to help the owner out and hope that someone can help with some direction and opinion.

1-The wire to the expansion tank is not attached and just hanging loose I reattached it and made sure it is full of water and no difference. I am not sure what signal from this wire is the system error signal? Is it grounded-closed to signal a water level fault or is it open to signal a water level fault?
2- where are the buzzers and what is the best way to get to them? I hate to cut them out but I may need to do that and install a light since the alarm sounds even with all gauges signal things are good. at this point the alarm is crying wolf.

3-oil pressure fault switch. What is the error state.? does it ground out to switch a error or does it open to switch an error?
3b- is there a oil temp switch?

4- The Jack switches. do they all connect in series or do they all try and throw a relay? how do they work? where are the switches and what do they look like.

5-Do the steps and door signal a buzzer? are there any other places to look?

6- is there one buzzer for each warning?

7-Kysor how is that related to the buzzer. reading posts on the old forum it sounds like there is a redundancy of buzzers

8-does anyone have a diagram?

9- If a warning light that spells OIL or BATT or TEMP is called an idiot light, What do you call a warning buzzer that only sounds BUZZZzz?

thanks in advance

[Robert Britton]

(12-26-2014 02:47)GregOConnor Wrote:  Trying to stop an alarm buzzer from sounding. '89FC has an alarm buzzer that sounds when the engine is on. I guess the FC is an 88 1989 300 hp cat 3208 model. The alarm stopped sounding several times, once in a parking lot at 5 mph after hitting a speed bump it stopped but then restarted while backing up a driveway. I note that there were a bunch of hacks under the dash that I reconnected and cleaned up so I may have reattached a wire to a control that had the issue or it is an entirely new issue. I plan to go to San Diego this week to help the owner out and hope that someone can help with some direction and opinion.

1-The wire to the expansion tank is not attached and just hanging loose I reattached it and made sure it is full of water and no difference. I am not sure what signal from this wire is the system error signal? Is it grounded-closed to signal a water level fault or is it open to signal a water level fault?
2- where are the buzzers and what is the best way to get to them? I hate to cut them out but I may need to do that and install a light since the alarm sounds even with all gauges signal things are good. at this point the alarm is crying wolf.

3-oil pressure fault switch. What is the error state.? does it ground out to switch a error or does it open to switch an error?
3b- is there a oil temp switch?

4- The Jack switches. do they all connect in series or do they all try and throw a relay? how do they work? where are the switches and what do they look like.

5-Do the steps and door signal a buzzer? are there any other places to look?

6- is there one buzzer for each warning?

7-Kysor how is that related to the buzzer. reading posts on the old forum it sounds like there is a redundancy of buzzers

8-does anyone have a diagram?

9- If a warning light that spells OIL or BATT or TEMP is called an idiot light, What do you call a warning buzzer that only sounds BUZZZzz?

thanks in advance

Greg, I would suspect the jacks. The control levers are on the floor left side of the driver seat. Try deploying jacks and then bring them back to stowed position. If one of the jacks has a weak spring it can cause the buzzer to go off, most notably on bumpy roads (or speed bumps), or maybe it just was not brought all the way up after last use.

[GregOConnor]

I got an email with a schematic from a good friend. I will post that some place later. running thru the diagram of appliances in the schematic I see a part called Engine Warn Module EWM with 6 electrical connections on it. this module is connected to a buzzer from a point labeled #6 showing it is using a green and white wire. the input signals to this EWM are water temp, water level and oil pressure.

I am thinking that the Jacks are powering yet another buzzer but they might be blowing this buzzer with another input wire. I plan a trip to San Diego to help the owner out tomorrow. If I find the EWM removing the green and white wire should stop the buzzer given one of the three switches of water level, water temp and oil press are the issues. I found an image of what the EWM should look like

[GregOConnor]

First look was to check out the Jack warning system. The jack alarm set up seem to have mercury switches and I think they are hooked up to a different alarm than the one that is buzzing. the PO of this bus hacked the jack buzzer also as they are disconnected some place. I was able to find the Kysor Cadillac alarm module which is located at the bottom of the steering column left side under the carpet flap. The diagram that Curt sent showed the green/white wire was to power the buzzer. Disconnecting green/white stopped the buzzer. Since the Kysor Module only looks at water level off the green/black and the water temp warn and oil press warn are hooked to the tan/orange I re hooked the buzzer green/white than disconnected the wire to the oil press warning lead which stopped the buzzer. I can only guess that the oil press switch grounds out until it reaches a set safe pressure. Since the bus oil pressure is reading 40 and seems to react normal to engine rev I think it is safe to assume the oil press switch is f'ed . The oil press switch is connected to a oil line tee under the driver floor next to the engine . It looks like the switch was replaced prior and I cant assume the switch is the correct one so I need to source the part and get one ordered. Leroy once drove home the practice of making the switches and senders match up with the gauges and modules so I hope there is a Kysor switch replacement that is available. I never found the actual buzzer.
here are some images . the pdf is the fc master wire diagram and one pdf is a copy of a Kysor owners manual.

  Elec Master Wiring FC.pdf (Size: 417.07 KB / Downloads: 598)
  KYSOR ALARMS SERVICE AND INSTALLATION.pdf (Size: 8.78 MB / Downloads: 995)