Engine Sensors/Senders
 

I'm finishing up the install of my new 540's and had a question about how to wire the senders for the guages. I have Gaffrig/Livorsi gauges and their senders. My wiring harnesses have the tan/blue wires for the alarm buzzer as well as the appropriate wire for the guage sender wire. Is it okay to connect both wires to the sender, i.e. tan/blue alarm buzzer wire, and the light blue wire for the oil pressure guage?

I understand that the senders are nothing more then thermoresisters, I guess the only question is whether the Livorsi senders have the same ohm range and ohm/temperature realtionship?

Re: Engine Sensors/Senders
 

I'm not exactly sure what you're asking. But I think you want to use a single sender for oil pressure and alarm. The sensors for the alarm buzzers are different from the guage sensors on Mercs. So you cant use an oil pressure sender for the alarm.
Gary

Re: Engine Sensors/Senders
 

Monty, are you saying that you want to use one sender for both the Alarm and the gauge ? I would prefer to have the redundancy of two senders. My 2cents...

Re: Engine Sensors/Senders
 

I would say no you will need the separate sending units.

The gauges work off of the variable resistance from the senders that gaffrig provided with the gauges.

The alarm circuit works off the sender that is set at a predetermined pressure to activate the switch inside of the enclosure that closes to ground. It's a switch and is either on or off.

Re: Engine Sensors/Senders
 

Sorry if my question wasn't clear.

Yes, I was asking if I could use the same sendor for both the guage and for the alarm. I was looking at the wiring schematic and the same tan/blue wire circuit is used on the oil pressure sender, tranny temp switch, and water temp sender for the alarm, but each sender also has it's own color coded wire for the appropriate guage.

As Scott mentioned, I was wondering if the Livorsi senders had different ohm range, etc than the Merc senders for the warning system which it seems they probably do.

Re: Engine Sensors/Senders
 

What he said:) You can try it but since the sender for the gauge is constantly sending a signal i don't think your alarm would ever shut off. :eek:

Re: Engine Sensors/Senders
 

The alarm sensors provide an on/off switch ground for a buzzer that has voltage supplied with the key on. Not sure if the guage would be damaged if you wired the pressure guage into that.
Wouldn't try it, Gaffrigs are expensive.
Gary

Re: Engine Sensors/Senders
 

they are different ...plus the redundency ..