RE: oil pressure sender resistance?

["Bain, Bill" <Bill.Bain@domain.elided>]

OK guys, this thing has gotten all twisted: 

My understanding is that the V6 engine has 2 sensors related to oil
pressure:  the sender that provides a signal for the oil pressure GAUGE
and one that provides a signal for the oil pressure (really oil
presence) idiot light.  I'm told that the idiot light sender consists of
a heating coil and a bimetallic strip.  Upon starting the car, the coil
will heat up and if there is oil in the system, the oil will keep the
bimetallic strip from heating up and breaking contact.  The infinite
resistance that ensues due to the movement of the bimetallic strip and
the broken contact will be interpreted by the ARC as "no oil" and
trigger the idiot light.  My understanding is that the oil pressure
gauge sensor circuitry and the oil pressure idiot light circuitry are
not related, but let me know if I have misunderstood how the system
works.

Apparently the sender for the idiot light has a tendency to leak and the
previous owner simply removed it and plugged the hole.  Removing the
head to replace the idiot light sender is not an option at this point --
I'd be nuts to take the car off the road to remove the head to fix an
idiot light that's not needed anyway since the gauge works.  The oil
pressure gauge works and all I want to do is stop the stupid idiot light
since there's no sender for it to read from.  My understanding, which
may be wrong, is that since the idiot light sender conducts some current
when there's oil in the system, replacing the idiot light sender with a
resistor seemed like an appropriate fix.  

Unfortunately, since there's no idiot light sender, I don't know which
wires went to the idiot light and there are several wires that are
unplugged behind the engine to "choose" from.  Can anyone tell me what
the color(s) of the wires are that connect to the idiot light sender?

Bill Bain 
AROC Atlanta 
'83 Spider 
'87 Milano 

-----Original Message----- 
From: sherwood white [ mailto:vze2skmv@domain.elided
<mailto:vze2skmv@domain.elided> ] 
Sent: Wednesday, December 11, 2002 9:30 PM 
To: Ferdinando Di Matteo 
Cc: Bain, Bill; alfa-digest@domain.elided 
Subject: Re: oil pressure sender resistance? 


if you would like your oil pressure gauge to read anywhere near right
with the motor off you should get about 220 ohms from the connector to
ground it is a resistor and the resistance matters Ferdinando Di Matteo
wrote:

> For Bill Bain and other ill advised Alfisti, the oil pressure ender is

> a variable  pressure diaphram , not tem activated   resistor. 
> Replacing with a fixd resisor of any value IS STUPID! If you don't 
> know for sure, lease don not offer bad advice.  Fred Di Matte 
> -- 
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