97 Mercury XR6 alarm problems

[Tim.Johnson]

I have 97 Astro 1800 with a 97 Mercury XR6 150. The high heat/low oil alarm keeps getting triggered. I have taken it to a boat mechanic twice. The oil injection has been disconnected and now gets manually mixed. New water pump. Mechanic said he can’t find any problems. Motor is not overheating. I thought it was a bad ignition switch because the alarm would go off when I slightly turned the ignition back to the left, so I put a new switch on, but it didn’t fix it. I had the boat out today and drove it around for awhile. Trolled around for a bit. After sitting for 15 minutes or so, I turned the key on and the alarm triggered. I’m at a loss.

 

[saltchuckmatt]

I have 97 Astro 1800 with a 97 Mercury XR6 150. The high heat/low oil alarm keeps getting triggered. I have taken it to a boat mechanic twice. The oil injection has been disconnected and now gets manually mixed. New water pump. Mechanic said he can’t find any problems. Motor is not overheating. I thought it was a bad ignition switch because the alarm would go off when I slightly turned the ignition back to the left, so I put a new switch on, but it didn’t fix it. I had the boat out today and drove it around for awhile. Trolled around for a bit. After sitting for 15 minutes or so, I turned the key on and the alarm triggered. I’m at a loss.

I would say you need to trace the wires and look for a short...bare wire somewhere.

 

[Dukedog]

did it get all tha oiler stuff removed??? ie: pump (proper block off kit), tanks, pressure valve, module... if tha module is still on it and has power to it that could be a problem... if all those items are removed and you still get a constant beep for no apparent reason (over heat) then you have a heat circuit problem.. either wiring, sensor or horn.

if tha module is still on it get rid of it, or make sure tha purple wire going to it is disconnected and capped off...

 

[QBhoy]

Hi. Did you bypass the alarm for low oil or secure the float switch in the up position ? Or leave the tank full ? Need to do one of these at least.

 

[Tim.Johnson]

Thanks for the feedback. I’m not much of a mechanic. To my knowledge, the mechanic I took it to removed all of the oil injection parts. Oil tanks are gone. He tested the motor after running it hard and didn’t detect overheating. I think the alarm issue is related to an issue I’m having with the gauges. When the alarm issue started, my gauges stopped working. I’ll take your advice and see what happens.

 

[QBhoy]

Thanks for the feedback. I’m not much of a mechanic. To my knowledge, the mechanic I took it to removed all of the oil injection parts. Oil tanks are gone. He tested the motor after running it hard and didn’t detect overheating. I think the alarm issue is related to an issue I’m having with the gauges. When the alarm issue started, my gauges stopped working. I’ll take your advice and see what happens.

Ah. Could be a continuity issue behind the dash perhaps. Corroded wiring or similar. Something shorting perhaps. But I’d just make sure of or ask the mechanic around his method of dealing with the bypass of the low oil alarm circuit. If that hasn’t been linked out or dealt with properly, might cause issue. Do the remote feed tank is removed now ? Is there still a tank on the side of the engine ? Think there may be a sensor there too, if you have that. Can’t remember and Not totally familiar with this age of 150. My 150 is from the 80’s.
Failing all that. Could just be as simple as a wiring issue. I’d have a good look behind the gauges and dash. Have a gentle fiddle around the wiring.

 

[saltchuckmatt]

I have 97 Astro 1800 with a 97 Mercury XR6 150. The high heat/low oil alarm keeps getting triggered. I have taken it to a boat mechanic twice. The oil injection has been disconnected and now gets manually mixed. New water pump. Mechanic said he can’t find any problems. Motor is not overheating. I thought it was a bad ignition switch because the alarm would go off when I slightly turned the ignition back to the left, so I put a new switch on, but it didn’t fix it. I had the boat out today and drove it around for awhile. Trolled around for a bit. After sitting for 15 minutes or so, I turned the key on and the alarm triggered. I’m at a loss.

Is it a constant beep or a beep....beep....beep.

I keep reading a few things it could be and a couple of posts said bad stator makes the alarm go off.

Here is my new such post.

 

[Tim.Johnson]

Is it a constant beep or a beep....beep....beep.

I keep reading a few things it could be and a couple of posts said bad stator makes the alarm go off.

Here is my new such post.

It’s a solid beep. Just read your post. My non mechanical brain is struggling. Haha

 

[racerone]

Tested the buzzer itself ??

 

[saltchuckmatt]

It’s a solid beep. Just read your post. My non mechanical brain is struggling. Haha

Solid beep means overheat. If your mechanic says "no overheat" and you believe him than your overheat sensors seems to be giving you false signals.

If you want to double check your mechanic, get one of these from harbor freight and check head temp. 140 to 160 range than once warmed up.
No need to have much mechanical knowledge.

If okay learn how to test sensor.

 

[Tim.Johnson]

Solid beep means overheat. If your mechanic says "no overheat" and you believe him than your overheat sensors seems to be giving you false signals.

If you want to double check your mechanic, get one of these from harbor freight and check head temp. 140 to 160 range than once warmed up.
No need to have much mechanical knowledge.

If okay learn how to test sensor.

Could a bad sensor trigger the alarm?

 

[saltchuckmatt]

Could a bad sensor trigger the alarm?

Yes.

Have you told your mechanic of the issue?

 

[Dukedog]

that sensor should not close/alarm till motor is about 200+/- degrees so no doubt if motor is hot or not... that little heat gun from HF is well worth tha investment though..
on your motor, on tha starboard side justa above tha switch boxes, jus to tha left of tha start solenoid there is a small, plastic terminal block.. there will be two tan/blue's (its possible that they may be jus tan, some are and some are not depending on what they did at mercury at tha time which is another story) under one screw/stud... tha over temp sensor is right under tha plug for number one cylinder.. next time it "alarms and/or beeps" disconnect tha tan/blue at that terminal block that comes from that sensor.. if tha motor is NOT hot but tha beep/alarm stops then sensor is bad... if beep/alarm continues disconnect tha "other" tan/blue that goes into tha harness female 8 pin plug.. if alarm still continues after you disconnect tha "other" tan/blue unplug tha 8 pin harness.. if alarm stops that indicates a problem in tha motor side of harness.. if alarm continues it indicates a problem with tha boat side of tha harness.. there is only one thing that will make tha alarm sound and thats a ground in its circuit..

if ya gonna do anything on your motor yourself ya gonna need an OEM manual for it.. send me an email addy and i'll send ya one in pdf form....

 

[zacharytboyd]

that sensor should not close/alarm till motor is about 200+/- degrees so no doubt if motor is hot or not... that little heat gun from HF is well worth tha investment though..
on your motor, on tha starboard side justa above tha switch boxes, jus to tha left of tha start solenoid there is a small, plastic terminal block.. there will be two tan/blue's (its possible that they may be jus tan, some are and some are not depending on what they did at mercury at tha time which is another story) under one screw/stud... tha over temp sensor is right under tha plug for number one cylinder.. next time it "alarms and/or beeps" disconnect tha tan/blue at that terminal block that comes from that sensor.. if tha motor is NOT hot but tha beep/alarm stops then sensor is bad... if beep/alarm continues disconnect tha "other" tan/blue that goes into tha harness female 8 pin plug.. if alarm still continues after you disconnect tha "other" tan/blue unplug tha 8 pin harness.. if alarm stops that indicates a problem in tha motor side of harness.. if alarm continues it indicates a problem with tha boat side of tha harness.. there is only one thing that will make tha alarm sound and thats a ground in its circuit..

if ya gonna do anything on your motor yourself ya gonna need an OEM manual for it.. send me an email addy and i'll send ya one in pdf form....

Hi Dukedog,

I bought this boat from Tim Johnson and I replaced the temp sender, the temp sensor, and the alarm control module…now the key on test works with 4 short beeps and when I ran the engine, the temp only gets to about 150 degrees…the alarm goes off when engine is running in a pulsating beep. No alarm with engine off, key on. I’m thinking it’s because of where the green wire is connected. Thoughts?

 

[Dukedog]

could be... they will usually run bad if thats tha case.. that wire reads that post (usually number two) firing.. it calibrates between it and magnet (rotation sensor on top of oil pump) to module.. no fire or no rotation ya get a alarm.. thats how its SUPPOSED ta work but its not all that dependable in my experience.. some say you can move tha green wire to tha next post down and test.. may/may not work.. i had very little ta do (problem solving) with any of tha oiler stuff over tha years.. my junk either didn't not come with oiler (hi perf.) or i would eliminate it pretty pronto... i can send ya an oem manual if ya want...

 

[Faztbullet]

You dont need the module since oiler has been by passed, Disconnectt the purple wire to module

 

[zacharytboyd]

that sensor should not close/alarm till motor is about 200+/- degrees so no doubt if motor is hot or not... that little heat gun from HF is well worth tha investment though..
on your motor, on tha starboard side justa above tha switch boxes, jus to tha left of tha start solenoid there is a small, plastic terminal block.. there will be two tan/blue's (its possible that they may be jus tan, some are and some are not depending on what they did at mercury at tha time which is another story) under one screw/stud... tha over temp sensor is right under tha plug for number one cylinder.. next time it "alarms and/or beeps" disconnect tha tan/blue at that terminal block that comes from that sensor.. if tha motor is NOT hot but tha beep/alarm stops then sensor is bad... if beep/alarm continues disconnect tha "other" tan/blue that goes into tha harness female 8 pin plug.. if alarm still continues after you disconnect tha "other" tan/blue unplug tha 8 pin harness.. if alarm stops that indicates a problem in tha motor side of harness.. if alarm continues it indicates a problem with tha boat side of tha harness.. there is only one thing that will make tha alarm sound and thats a ground in its circuit..

if ya gonna do anything on your motor yourself ya gonna need an OEM manual for it.. send me an email addy and i'll send ya one in pdf form....

Hi Dukedog,

I bought this boat from Tim Johnson and I replaced the temp sender and the temp sensor, now the alarm is on as soon as you turn the switch on. Could you send me the PDF? zacharytboyd@gmail.com

 

[zacharytboyd]

You dont need the module since oiler has been by passed, Disconnectt the purple wire to module

Will the hi temp still sound without the purple attached?

 

[zacharytboyd]

could be... they will usually run bad if thats tha case.. that wire reads that post (usually number two) firing.. it calibrates between it and magnet (rotation sensor on top of oil pump) to module.. no fire or no rotation ya get a alarm.. thats how its SUPPOSED ta work but its not all that dependable in my experience.. some say you can move tha green wire to tha next post down and test.. may/may not work.. i had very little ta do (problem solving) with any of tha oiler stuff over tha years.. my junk either didn't not come with oiler (hi perf.) or i would eliminate it pretty pronto... i can send ya an oem manual if ya want...

Zacharytboyd@gmail.com

 

[Faztbullet]

Yes....