Coolant and alarm sender

[Tom M]

Guys:

Is the temperature sender to the gauge a different sensor than the temperature sensor to the alarm?

The sensor I found has  2 tabs/2 wires,  I presume this is to complete a circuit?  Or am I wrong and they are grounded and one is for the alarm and one for the gauge sender?

 

the reason I ask is my alarm is going off,  the gauges show appropriate readings, so I am troubleshooting the sensors.

oil pressure checked out.

this system has the SMX card.

let me know your thoughts.

 

thank you!

 

 

 

Topic

[pwrobert]

Most fittings points are 1/2″ NPT so you would either need a bushing adapter or get the appropriate 1/2″ sender or switch.  I am not aware of any 3/8″ locations on most engines.  Usually either 1/4″ or 1/2″.  Asapters are needed for anything else.  Oil is usually 1/8″ NPT or sometimes Metric.

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Tom M

[Tom M]

Names

I sure am.  I guess that is why I am on the forum… need a little help. For all these years I thought the SMX card system and the “switches” were integrated.   It was only in the last couple days, when I had to fix this stuff myself, did I get that sorted out.  The historic motors had both switches for temp and oil pressure, figured the recons were the same.   I have cracked the code of this whole system.  Pretty easy now I think.  I see there is a 190d F switch for sale by SB.  I am running SB 160d F thermostats.  I am away from the boat now.  There are existing plugs shown in the temp switch suggested locations for the 6bta under Tony Tips.  Surly one is 3/8” npt thread? Maybe at the locations labeled “good”  & “better”  are 3/8”? Or will I need an adapter?

 

Thank you for putting all the Tony Tips together.

 

 

 

[Rob Schepis]

Are you confusing sending units and switches?  All is explained in this article.  Engines comes with senders, not switches.  Switches are upgrades for custom alarm setups installed either by the boat builder or the owner. https://www.sbmar.com/articles/redundant-alarms-least-expensive-engine-insurance/

[Tom M]

Wiring/gauges/alarm

Thanks for your thoughts Tony 

 

there are two systems 

One alarm system that is playing up was wired up in 2007 per SB instructions, it is the SMX card system.  the only issue now is the Voltage alarm goes off intermittently although we have adequate voltage 

there is a redundant  good old fashion bulb and buzzer system.  This was going off inexplicably,  but we did find when we disconnected the alarm to the tower it works fine at the lower helm.   That alarm is connected to the oil pressure alarm sensor.  There is a wire spliced in, by the factory, that was coiled up from 2007.  Apparently this can be used for another sensor.  

My question is:  Are SB recons sold with a high coolant temperature sensor for an old fashion bulb/buzzer alarm system?  I have a 2007 & 2018 recons from SB.

the only coolant temp sensor shown on the website info is the two wire feed for the gauge.  I can’t find the alarm sensor, if it exists, on the motor or the website info.

on the other, the card system, maybe there is a little corrosion in the system (although I don’t see any) causing voltage drop, maybe I need a new card?

[Tony Athens]

wiring /gauge/alarm questions

There are multiple pictures, diagrams , etc on this web site showing factory wiring, including specs on the sensors for temp and OP.. The “alarm board” is there to “interpret” the factory specified  VDO sensors so you have alarms.. It does not affect how the engine itself  starts or runs……  Once “someone” rewires things per some other spec, or ??, I’d say you are on your own.

[Tom M]

No alarm sender on recons?

It seems that there is no go/no-go alarm sender for coolant on Seaboard recons?

could Corey or Tony chime in? <br /><br />

it seems it would want to go below the alternator in the port shown in the photo, correct?

[Tom M]

Solved for now

I am in Mexico

the workmanship is so poor, hard to put into words, except I am lucky to be alive

someone wired the tower alarm light to the sensor input

so disconnected that and all good

the beacon seems to run independent of the SMX card and indicators

seem to have the low voltage alarm going off on the card system but have 14+ volts

that is a minor issue to me for today 

[Tom M]

Alarm sensor

If I can find the Water Temp Alarm Sensor I could bypass the card and get something going for temporary 

any hints? For a 6bta 370?

 

[Tom M]

Pic – overall

Overall pic 

[Tom M]

Pic

Sensor for gauge 

[Tom M]

Low oil goes away

Low oil goes away once the engine is running

 

we have 14v

 

historically low voltage has not set off the upper alarm beacon

 

[Tom M]

Pic

Another

[Tom M]

Pic

Attached is a pic

[Rob Schepis]

Two terminal senders are floating ground.  Do you have a secondary alarm panel or is the alarm you are referencing the one that is integrated in your instrument cluster? If the later, and your gauges are reading normal, it appears that the issue might be a fault in the circuit board that signals the alarm.  Send a pic of your gauge/alarm panel(s).

[pwrobert]

The coolant temperature and the coolant alarm typically have seperate senders like the oil pressure guage and Low Oil pressure alarm. The Low Oil Pressure Alarm is the one that momentarily goes off when cranking the engine.  On my 6BTA I do not have an engine installed High Temperature Alarm.  However, I do have a high Exhaust Temperature Alarm mounted on the Wet part of the Exhaust tube right after the mixer dumps it coolant water. Loss of water causes it to go off with both a Buzzer and a Red Light on the panel.

Usually the VDO/SMX senders have two poles – one Ground and the other is for the Signal wire to the Gauge and  a similar sender with the sender wire ging to the Buzzer from an Overheat alarm.  But VDO makes several connection types – Single wire (Signal only) ground is through the body to engine, and Double Wire as mentioned. Sometimes the Overheat and Low Oil Pressure senders send their signal wires to the same Buzzer.  There is a Buzzer that has two different sounds  (one High and One Low Pitch) for differentation of oil or Temp.  I have seen a Combo Oil pressure Gauge sender and Low Oil Pressure Alarm all built into one Sender but am not familiar with one like that for Engine temperature. There may be one.

 

If Temperature is Ok and the Overheat buzzer is sounding the first thing I would check is that the sender has not lost it’s Ground connection – either broken or corroded connection.  Secondly, the Overheat Sender could be bad and switching it out with the one from the other engine if it is a twin installation is a good diagnostic check.

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