Now I'm Really Confused

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,795
Had a response I made to a V6 temp problem questioned. I started back tracking to verify what I said and pulled out my 3 cyl 90 hp service manual. It covers '94 thru '98 and supposedly above but I don't know how long that was.

Anyway I start differentiating between the use of tan and tan/lt. blue color codes on the warning circuit wiring between OT sensor, low oil sensor, and the warning horn.

I know temp is a solid alarm and oil is a beep. Seems to me you need some electronics to perform that so one would look to the "warning module" to perform that function.

There is a separate section that describes the warning system, with schematic and that includes a module.

If I go to the engine schematics however, for the '94 thru '96 engines they show one, but for the '97 and '98 there is none.

So the question is, how do you get two different warning indications from a circuit that has both warning sources tied together and connected to the low side of the horn?

Mark

Fine, but on the later engines
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,225
Re: Now I'm Really Confused

Mark, Are you sure you are supposed to get different warnings? If so, then the sender needs to provide the warning signal. For example, the senders ground when they detect trouble. The sender could therefore pulse the ground, giving a "beep-beep-beep" sound.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Now I'm Really Confused

The oil warning module grounds the horn line to sound it. It normally is an intermittent signal, yielding a beeping sound.

The head overtemp switch is connected to that same horn line, and if it actuates causes a solid horn tone.

Either source is open (not connected) under normal conditions, so either source can independently sound the same alarm.

Technically, it's called a "wired or" circuit.

hope it helps
John




Had a response I made to a V6 temp problem questioned. I started back tracking to verify what I said and pulled out my 3 cyl 90 hp service manual. It covers '94 thru '98 and supposedly above but I don't know how long that was.

Anyway I start differentiating between the use of tan and tan/lt. blue color codes on the warning circuit wiring between OT sensor, low oil sensor, and the warning horn.

I know temp is a solid alarm and oil is a beep. Seems to me you need some electronics to perform that so one would look to the "warning module" to perform that function.

There is a separate section that describes the warning system, with schematic and that includes a module.

If I go to the engine schematics however, for the '94 thru '96 engines they show one, but for the '97 and '98 there is none.

So the question is, how do you get two different warning indications from a circuit that has both warning sources tied together and connected to the low side of the horn?

Mark

Fine, but on the later engines
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: Now I'm Really Confused

I found a schematic for a 1997 90HP. It does not show an alarm module like the older ones but it does show an oil warning module. Its hard to see but it looks like the only thing it does is give you the intermittant beep when the oil is low.
 

JUSTINTIME

Captain
Joined
Sep 2, 2006
Messages
3,284
Re: Now I'm Really Confused

blue is the oil alarm
tan/blue and tan are over heat

you will have a modual, which they do go out
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,795
Re: Now I'm Really Confused

I rechecked the schematic and they just call it a switch for the oil level. Maybe on the later model engines they just give you a solid horn and you have to figure out which it is.....OEM saved a couple of bucks by not using an electronic module.

Thanks for assisting guys.

Mark
 
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