Water temp sensor, alarm, guage

[captlee]

Rencently purchased a 1986 proline with a 1996 90hp Evinrude ocean pro on it. No guages on the instument panel work (I got the trim guage working today). Theres 1 aftermarket sending unit on the port side going back to a temp guage that doesnt appear to work. I checked the alarm/horn after reading another post, it was disconnected (the purple wire coming from the ignition was pulled loose from the connector on the alarm). When I put power to it made a very low static noise but no loud noise, grounding the tan wire made no differnce.

Its obvious the alarm needs to be replaced, but is there a way to test the factory sending units/ sensors in the heads? Can those be used with a guage or are they just for an alarm? If I were to go with a guage shouldnt it have 2 sending units, 1 in each head like the originals? Would this require 2 guages or just both sensors go to 1 temp. guage?

Im trying to decide if I should keep the alarm or go with an actual temp. guage. Ive also seen water pressure guages would that be a better choice?

Also... any help/advice with testing the tach and making sure its hooked up correctly would be appreciated. Thanks in advance.

Lee

 

[Chris1956]

Re: Water temp sensor, alarm, guage

Lee, It sounds like you need a service manual. Get an OMC one. That motor should have the quickstart and SLOW systems. These systems help start and protect the motor from overheating and use the temp sensors on the heads. It is obviously iomportant that the sensors function correctly.

See if the motor has a 8 pin connector, under the dashboard. If so, get a System Check Tach. It will have built in sensors for overheat, low oil and no oil.You should install a water pressure gauge instead of a temp gauge. They are a better indicator of a building issue.

The grey wire is the tach sender. The purple wire is power for gauges and other ignition accessories.

 

[captlee]

Re: Water temp sensor, alarm, guage

Thanks Chris, factory servive manual is enroute via e-bay. Just trying to get a jump on things beforte it arrives. Going to address the tach issue today and look for more stuff to fix hehe.

 

[captlee]

Re: Water temp sensor, alarm, guage

Replaced the 3 wire alarm horn for $75 (what a deal lol), it beeps once when the key is turned on. After 3-5 minutes it starts to make short beeps about 1 sec apart. Turn key off and back on again, same scenario after a few minutes. (sounds like one of those back-up alarms on trucks) If it were overheating I beleive its a constant beep? Is this an oil alarm? If so how do I silence it?

(Tach and guage issues fixed, thanks chirs )

 

[dajohnson53]

Re: Water temp sensor, alarm, guage

Replaced the 3 wire alarm horn for $75 (what a deal lol), it beeps once when the key is turned on. After 3-5 minutes it starts to make short beeps about 1 sec apart. Turn key off and back on again, same scenario after a few minutes. (sounds like one of those back-up alarms on trucks) If it were overheating I beleive its a constant beep? Is this an oil alarm? If so how do I silence it?

(Tach and guage issues fixed, thanks chirs )

The beep every second is "no oil". The sensor is at the oil part of the fuel/oil pump (VRO or OMS). It indicates that oil flow to the pump is not there or is insufficient for the speed of the engine.

 

[captlee]

Re: Water temp sensor, alarm, guage

The VRO pump has been disconnected, the line on the bottom of the unit is capped off, but the 4 wire connector is still plugged in (purple, black, gray, tan). Can I just disconnect these wires to silence the no oil alarm?

Also while i was loking around the red pointer wasnt in line with the solenoid, would this cause a rough idle and stall at idle/trolling speeds?