Coolant Temp Gauge / Sending Unit Issue

[Scott Johnston]

Interesting issue occurring with my 6BTA’s.
When I start them up both guges are reading the same and come up to temp and run normally 180-190ish.
When I have been runing for a while like yesterday the STBD temp creeps up to 200+ however the Port remains normal (at low rpm’s).
If I bring up the rpm’s on the STBD engine no change however if I bring up rpm’s on the Port engine the temp on the STBD side comes down to normal???
Coolant system has been maintained, brand new impellers, and it only happens after a while and when I am at low idle speeds.
If I’m running all is well.
How could the opposite engine rpm’s effect the other engine as described above….I’m puzzled?
Think def electrical issue here?
Thanks

Topic

[Scott Johnston]

Thanks Shawn.
I’ll check them. I actually removed the stock plugs and crimped on epoxie heat shrink fittings and then used a bus bar to make the attachments from teh engine to teh harness and bypassing those plugs all together. Great advice from a local marine electrician.

[Keith Pleas]

@Shawn – I have the same engines – I’m not experiencing that issue but I’d like to spray some corrosion protection in those harness plugs. Can you tell me (an engine novice) exactly where these are located?

[Shawn]

Could possibly be a ground issue or maybe a loose connection at the sender. If you have the stock harness with the plugs, they’re known to corrode, could try cleaning them up too.

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