Coolant Temp Alarm

[Steve Bryan]

Can’t trace my temp alarm cause. On the hard for 9 days working on the bottom. ½ hour back in the water and the alarms go off. Alarm comes on when starting dead cold, even replaced the VDO sender unit. Checked all fluids and flow with temps on both engines about the same reading with infrared.
Been reading and following the forum for years and appreciate all your info.

Topic

[GARY P BLENKHORN]

Did you ever solve this problem? I have the same issue on a 1993 GB 36 Classic with twin Cummins 6BT5 – 9m. I have run out of ideas.

[Steve Bryan]

Still working on mine. Swapped all relays, separate pair under the upper helm too, no changes. Engine warms up and then the alarm goes on and off, some times continuous other times 15 minutes all with normal engine temps. Used a continuity tester with no issues, but with intermittent ocurances, hard to tell. Mine has two wire connection at the engine temp sensor, rather then the one in the manual circa 1993. The relays and alarms are run separate to each helm, redundant, but not finding the connection, must be in the wiring harness. Still looking and open to ideas. Thanks

[bj-kluge]

same problem

Hi, i come over this.

i have the same trouble as you probaly.
The alarm for water/temperature start when im starting the engine cold,and maybe stops 3 sec after or a hour later. And its comes up with the alrm on the fly.. 1990 mod. 6bta5,9

[Steve Bryan]

Thanks, will try tomorrow!

[Rob Schepis]

Both engines throwing false alarm or just one? Can you swap components between the two?

[Steve Bryan]

Looks like the original 1993 temp alarm system. Engine temp system appears to be open with closed relays attached to each alarm at each helm station. All alarms, relays and temp sensors read the same (continuity wise). Alarm starts with cold engine start . Ran both engines up to operating temps and all parts basically the same temps. No circuit boards or reset buttons. Thoughts on what to test next?

[Steve Bryan]

The lower helm station has the actual buzzer/alarm under the helm with the lights above. We found the warning light only worked on the fly bridge but alarms worked at both.

[Rob Schepis]

Steve Bryan wrote:

Where would I look for the card?

Back side of instruments, something like in this pic. Any pics you can post?

[Steve Bryan]

1993

1993

[Steve Bryan]

Not sure PCM card? Original GBanks alarms not exposed to weather. Nothing redundant or switches observed on the engines. Just alarms & lights at both helm stations. Where would I look for the card?

[Rob Schepis]

This is factory OEM alarm setup with PCB board controlled alarms, correct? (Not a redundant system with real switches installed in the engine.) If so, sounds like a bum PCB board. Is it in the weather or wet conditions, that will result in early demise..

[Author]

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