Water temp sending unit, oil pressure switch functionality with gauges

I'll be installing mechanical Autometer water temp and oil pressure gauges this weekend on my 2004 GT. I'm trying to decide if I should retain the functionality of the stock (idiot) gauges. I did away with them on my 95 GT.

For the water temp gauge:

1. Does the factory sending unit do anything other than control the temperate gauge in the instrument cluster?

2. If I decide to keep the cluster gauge working, is there any problem with using a T fitting where the sending unit currently resides and attaching the original sending unit to one end of the T and the Autometer one to the other end? This assumes I can come up with an arrangement that will fit the available space. Any grounding issue with the factory one?

3. Any other relatively easy locations I could install the Autometer sending unit?

For the oil pressure gauge:

1. Does the factory oil pressure switch do anything other than control the temperature gauge in the instrument cluster?

2. If I decide to keep the cluster gauge working, is it possible to install the Autometer sending unit in the plugged opening on the bottom of the oil filter housing? If not, any ideas for where to install the sending unit?

I did come across a few ideas like

http://neptune.spacebears.com/cars/stories/oilgauge.html

and

http://www.miracerros.com/mustang/gauge.html

The first one seems like it'd work well but I'm not sure it's worth the hassle. The second one (even though it's supposedly about a 2000 GT) does not seem to match that the front of my engine looks like.

Thanks for any tips.

Rick

I just talked to a Ford tech. Hopefully he's got his facts straight.

The coolant temp sensor does send input to the computer. Info like telling engine to run richer when cold, etc. So, I better come up with a decent way to retain this sensor. Still looking at a T since I don't really care if it looks a bit off.

The oil pressure switch is not tied to the computer. If I can't use the secondary port in the oil filter housing for the Autometer oil pressure output, I think the stock oil pressure gauge goes bye-bye.

Rick

sgarlic,

sgarlic said:

It sounds like you're overthinking things a bit, Rick. <snip>

Click to expand...

Me, a software engineer with 20 years experience overthinking things? Nah, LOL. Talk about bang on! Gotta watch that tendency of mine!

Thanks for the oil pressure gauge link. That'll be a great help.

With respect to the engine coolant temp sensor, the Ford tech told me the one sensor controls the gauge AND the PCM input. Disconnecting the one at the front of the engine (on the same physical surface as the thermostat housing but towards the passenger side) does cause the gauge to stop working. This sensor is part # F5AF 12A648-AB and is the coolant temperature sensor that does the dual duty. Whatever the case, I want to leave this sensor operational. Are there any particular block plugs to avoid using for the coolant temp sensor for the Autometer gauge? Any one that is ideal?

Thanks to everyone for your patience and help.

Rick