Good evening. Let me start by saying that I've read past posts on this subject, including my own lol. I've decided to buy some aftermarket gauges for my 79 F250 460. Oil pressure, Temperature and Volt meter. So now I have questions:
Oil pressure, from what I've read, the sending unit goes at rear of the intake where the existing sensor is. Is this the only spot for the new tube, which by the way will not be the plastic one that comes with it. If thats the only install spot, can new and existing (warning light) be used together? Their was mention of guys installing a "T" fitting for both but no mention of where to purchase it.
Temperature, see pictures. The neck , 1st pic, would be the easiest but whats the deal with thing on top? 3rd pic, is this the existing temp for the dash?
Volt meter, have no clue on where the wiring goes for this.
Any help and pictures of all would be greatly appreciated! Thank you.

 

This is your temperature sender. Your new gauge sender should go there. The sensor on the thermostat is part of the emission control, it operates a valve when the thermostat opens and the hot water rushes through. It's not functional anymore, but it's not a good place to put a temp gauge sender.


The oil pressure sender hole is in the top of the block behind the intake. You can install a brass Tee with a close nipple from any hardware store

to run both the factory gauge/light and a mechanical gauge. I did that on my truck. I don't think I have a picture, though.

 

Can both temp gauges be used so that the factory dash still operates? Spice the red wire?

 

A fellow FTE members way of routing it. Good call on NO plastic oil pressure line, and use copper instead.

Check out Rocketman for amp meter to volt meter conversion. https://www.rccinnovations.com/index...=menu-volt-all

F100C7V or F100C7VO

 

No. A mechanical temp gauge uses a capillary tube and bulb sensor that fits into the hole and does not come apart. Care must be taken not to damage the unit.

Electric gauges will have their own matching sender and won't be compatible with each other. To run 2 temp gauges you need to find two sender holes.

 

Thanks for the Rocketman reference. There diagram shows connection to a switched source ie ignition switch or the radio power which is fused. I will have to look up a wiring diagram to see what wire that is.
Thanks

 

Thanks 52 merc. I figured but still asked. I'd like to leave the existing as is but now need a new location for the new tube. Thats why I had the pic of the neck but was told that was not a good spot.

 

Would this be an acceptable spot to put the new temperature sending unit while keeping the existing in place?

 

Are you asking about the 3-tree? If so, NO, that is your/a manifold vac port...

 

My 1967 Chevelle's factory oil pressure gauge used a white plastic or nylon tube, it leaked once, a few drips on my boot. It was original from Chevrolet. I had extra barrels as I had used the same type tube on oil gauges in several previous cars, 1/8" OD white tubing.. It was a simple fix cutting the tube, slip the nut onto the fresh cut line, slide a new barrel shaped ferrule on it, reinstall it before the family was ready to eat. My '77 has had the same white line since 1992, it comes off a tee under the electric sender. I allowed slack, and where the fittings are I have a inch of hose to support the tube. Where it runs through the firewall, it goes through another piece of small hose. A buddy once frowned on plastic or nylon, etc .... he used copper. It cracked and leaked, spew actually, oil under the hood. He thought was low oil pressure, until he opened the hood. Engine, vibrations, etc .... copper gave up. Copper work hardens, the plastic or nylon doesn't.

My temp gauge does not use a tee, I just put it where the electric sender was. The temp gauge uses no electricity, it has it's own small capillary feed. Way more accurate and meaningful than OEM was.

My volt meter get's it's input after I turn the ignition or accessory on and a small relay connects the VM direct to the battery on it's own line. It's fused at the battery.

 

Where does this fitting go? That looks like it's a sender in the water passage.

 

That is a vacuum port. The pressure from the cooling system would blow those little rubber vacuum caps off with a quickness. Do you have a plug or something on your thermostat housing to use? Or maybe on or near the passenger side of you water pump?

 

I will look merc 52.

 

52 Merc, looks like it goes nowhere. Also looks like a vac port. Should I plug both of these?

 

yes plug those as well. might be worth spraying some carb cleaner randomly at different spots on the manifold to see if you din anymore... no idea why you have so many