temp gauge pegged at zero

[BOATINGmatt]

I ahve a 84 wellcraft with an 88 hp 1980 evinrude....i just replaced my temperature gauge in the instrument pannel as it was not working...I hooked it up as shown in the instructions, s--to sender on motor, --I to ignition and G--groung...when the gauge is energized it gets pegged to zero and never moves...when the ignition is off the needle rises...any thought on why this is happening...I also hav a jumper wire installed from thr "l' light on the gauge to the "i" ignition terminal to energize the light which is working.
thanks

 

[Silvertip]

Re: temp gauge pegged at zero

Some gauges "float" when turned off and then go to zero when the ignition is on so that action is normal. The question I have however is what happens as the engine warms up? Any reading? What type of temp sender are you using and how is it installed. There are two types of senders. One type is much like the one in your car in that it screws into an unused port in the water jacket. The other is a contact type that is in contact with the cylinder head and is mounted with a head bolt.

 

[180shabah]

Re: temp gauge pegged at zero

using DVOM, what is the resistance from the sensor wire to ground? May be shorted.

 

[BOATINGmatt]

Re: temp gauge pegged at zero

Thanks....the needle floats when the power is off and then when energized pins at zero..when the enging warms up the needle stays at zero..I will check into the sending unit and get back to you, , I used the existing sending wire that was connected to the previous gauge and the existing sending unit..im not too familiar with them so i will look into it further

 

[180shabah]

Re: temp gauge pegged at zero

Ground the sensor terminal, the needle should peg, to the high side. If it does, your issue is either with the wire or the sender. Disconnect the wire from the sender and ground it, observe the gauge and report.

 

[Silvertip]

Re: temp gauge pegged at zero

Disconnect the sending unit and measure the resistance to ground. The sensor should read between between 33 and 240 ohms depending on how warm it is.