1988 88HPSPL Johnson heat alarm

[Doug Powell]

Turn ignition switch-get a beep. Start engine-alarm sounds-beep-beep, etc.(not a VRO). Engine cool-disconnect starboard heat sensor(sender?)-alarm goes off. Tried to remove sender-corroded in. Isn't this just a grounding switch that completes the alarm circuit for when things get too hot? Got to replace it-corroded in-do I just drill it out and insert new sensor? Know where I can get one at a reasonable cost?

 

[Joe Reeves]

Re: 1988 88HPSPL Johnson heat alarm

The water jacket plate must be removed in order to dig that faulty sensor out. And yes, it is simply a grounding type switch.

If that sensor is grounded, the horn should be sounding constantly, one steady long beep.

 

[eFish]

Re: 1988 88HPSPL Johnson heat alarm

I got one too...so far I got the heads off just checking it out! There is a rubber jacket around it so go 4 drilling it out.

 

[Doug Powell]

Re: 1988 88HPSPL Johnson heat alarm

The water jacket plate must be removed in order to dig that faulty sensor out. And yes, it is simply a grounding type switch.

If that sensor is grounded, the horn should be sounding constantly, one steady long beep.

Thanks, Joe. It appears that the hole through the water jacket is the same size as the one housing the sensor and that I could just drill it out w/o removing the jacket?? My sensor did not sound constantly but just beeped continuously, so I think it was making and breaking constantly. Doug Powell

 

[ezeke]

Re: 1988 88HPSPL Johnson heat alarm

Don't drill it out. The water cover hole is smaller than the cylinder head hole that contains the switch. Once you have the water cover off you can pry the switch out without damaging the water cover.

If you do manage to get the old switch out without damage, you still will not be able to get the new one back in. If you enlarge the water cover hole, there will be nothing to hold the switch in place and keep it watertight.

The temperature switches rarely go bad and when they do they simply do not work or they are stuck on.

Disconnect the temperature switch wire at the quick disconnect a few inches out and see if the signal is still there.

 

[Joe Reeves]

Re: 1988 88HPSPL Johnson heat alarm

The water jacket hole is smaller than the hole the sensor sits within..... do not drill that out! There are no short cuts.

You say "My sensor did not sound constantly but just beeped continuously, so I think it was making and breaking constantly".

This is confusing. The beep is either constant or intermitent. It sounds like you're saying that you have intermitent beeping sound, and if so, that shouldn't have anything to do with a overheat sensor.

(VRO Horn Warnings)
(J. Reeves)

1 - A steady constant beep = Overheating - The V/6 engines, possibly some others, have a fuel restriction warning which is also a steady constant beep.

2 - A beep every 20 or 40 seconds = oil level has dropped to 1/4 tank. (Late model engine = Every 40 seconds)

3 - A beep every other second = VRO failure, air leak in oil line, oil restriction, (anything that would result in a lack of oil being supplied to the engine).

NOTE - If the warning horn is the black plastic (overpriced) three wire type horn, the warning horn should beep once when the ignition key is turned to the ON position. If it does not, it is either faulty or someone has disconnected it (a stupid move!). At any rate, if it does not beep which indicates that the horn is non functional, find out why and do not run the engine until the problem is corrected.

 

[Doug Powell]

Re: 1988 88HPSPL Johnson heat alarm

Thanks guys. Let me state the case again. This is a non VRO engine. Has new powerhead and new horn. When I turn ignition on I get one beep from horn then when I start engine, in just a few seconds, horn starts to rapidly beep, beep continuously. Beeping stops when I disconnect starboard heat sensor or shut engine down. Engine is not overheating. Thanks for telling me to take the water jacket off instead of just drilling out. Have dug out rubber seal and wire came loose from sensor so it's gonna have to be replaced. Know where I can get one at a reasonable price??