Overheat warning

[biggjimm]

I've got a 1990 Tracker Pro 17 deep V with a 60 hp Johnson that I just serviced the water pump on as well as relocated the tell tale to the top of the head & replaced T-stat & the head gasket. There is no warning buzzer that I can locate anywhere. I would rather have a visual warning than a buzzer, can I just hook a red LED up to that tan wire coming from the temp switch so it would light up when that switch closes & I'll know what's going on? If so can I just tie into the tan wire that went to the vro which has been replaced with a non vro pump? Or should there be a wire in the control box that is tied into that system? If I remember correctly there is a tan wire & maybe a purple wire in the control box that doesn't go to anything. Thanks. Jim.

 

[emdsapmgr]

To help you understand your overheat warning system: There is a temp switch in the head. It is an on/off switch. When the cyl head temps get to 212 degrees, it will short to ground. When that happens, the overheat warning horn in the control box will constantly beep. When the cyl head temp gets below 175 degrees (still way too hot) the horn will silence. You can't run any variable gauge off the signal from that head switch-but you should be able to run a 12v light off of it. Question is-does your control box warning horn work? Short the brown temp sender wire to ground to check if the horn goes off. That horn is actually obnoxiously loud audio warning and really works pretty well for most of us.

 

[biggjimm]

Thanks emdsapmgr, I've already grounded the switch wire & there is no horn sound coming from anywhere. I've looked in the control box & there is no horn in there. There is a tan wire & I think a purple wire that are just hanging there & I didn't have my dvm with me at the time to check continuity & see if that tan wire was tied in with the switch or not. I thought if I put a LED on the dash & grounded it thru that tan wire from the switch it would light up when that switch closes & give me an indication that something is wrong. I just put a water pump kit in & if it was not for the S L O W function I would surely have trashed this motor as I did not know it wasn't cooling properly. I suppose I could wire a LED up real quick & ground that tan wire the same way you check the horn & see if it lights up? I figure it would work but I know that wire ties into the power pack & I didn't want to start wiring stuff up to that circuit & fry something. Thanks. Jim.

 

[biggjimm]

Let me ask this, were the warning horns ever mounted outside of the control box like say under the steering console? When I got this boat it was stripped down to the bare hull pretty much as it had been rear ended on the hi-way while previous owner was on vacation & the impound lot owner advised him to take anything off the boat that he could & take home with him to prevent theft while in the lot so they took everything off.
I ran into the previous owner later & purchased all the stuff & put boat back together so if that horn might have been mounted somewhere other than the control box it might have been overlooked & not put back on???

 

[jakedaawg]

The purple wires and the tan wire in the control box goto where the warning horn would be. They attach with flat spade connectors. The female connector on the wires.

Now, I could be wrong but I believe the purple wires that goto the horn are for the self check function that sounds a beep when you initially turn the key to let you know the horn works. The tan wire is the wire that sounds the different alarms from the low oil, no oil and hot sensors. Hope that helps with rigging up your light. Or you could just buy or find a warning horn.

 

[biggjimm]

Here's what I've found so far. There is a tan wire & a purple wire ihanging loose in the harness on the motor side of the bulkhead connector tthat goes to the control box. The purple is 12v switched w/ the key .The tan wire does not continue on the box side of the bulkhead connector, There is provision for that wire to continue into the control box but there's no wire there. That tan wire has continuity with the tan wire that used to go to the oil tank for the VRO (which has been removed) but there is no continuity with the tan wire at the temp switch. Should there be? In other words, if I put a light on the tan & purple wires at the control box & I ground that tan wire that used to go to the oil tank the light Will work if I ground the tan wire at the temp switch in the head I get nothing at the light. Any ideas? Looks like that wire from the temp switch goes to the power pack & then comes out & goes up front maybe??

 

[biggjimm]

Thanks Jake. I was wrongin my last post when I said grounding the temp switch did not light my test lamp at the control box but it in fact does. From what I can tell the purple wire is constant 12v when the key is on. I get 2v on the wires at the control box when the key is on & 12v when I ground the heat switch so I'm still trying to figure this out.
I'm going to get the horn that is supposed to be on it but wanted something I could use right now so I could run it. Thanks everyone

 

[biggjimm]

Maybe I'm thinking about this wrong. If I install this light where the warning horn should be will that tell me anything before the motor goes into S L O W mode or am I going to get a light come on the same time the S L O W is activated? If so I'll just wait til I can get the correct temp warning system to put on here .Thanks a lot guys. Jim .