water temperature help needed

[chopthebass]

I fired up my engine for the first time (i'll post a seperate thread video) and everything seems ok except water temp gauge doesn't work. The gauge connects directly to the sender via the supplied cable. So either the sender or the gauge is faulty? Is there anything else you can think to check?

Thanks!

[oldguy668]

Do you have 12V to the gauge with the key on?

[chopthebass]

I'm not sure. Other gauges work, and the 12v is common to all I think.

[frankeeski]

Two other things to check would be the ground connection to the gauge and the ground to the sensor. The ground on the sensor is typically made from the threads on the sensor. If you used teflon tape instead of paste you may have inadvertently disabled the ground path of the sensor.

[Jeff Kleiner]

Frank,
The fact that Chopthebass mentioned "supplied cable" leads me to believe that he is dealing with Speedhut/FFR gauges. If so they use two wires from the sender (ground and signal) and do not get their ground through the sender body. Indeed, the gauge has to be grounded (as well as have power and signal from the sender).

Chop,
Where do you have your sender located? If it is in the rear of the intake those ports are deadheaded without coolant flow so will be slow to respond and will not be accurate. If you used the top bung of the radiator the sensor will most likely not be wet or read accurately until all air is purged from the system. You can check the sender by reading resistance across the two terminals (or terminal and body for single wire types). You should see resistance change from cold to warm to hot. You can check this either by running the engine or by removing the sender and heating it up in a pan of water.

Keep us updated and good luck!

Jeff

[BEAR-AvHistory]

Two other things to check would be the ground connection to the gauge and the ground to the sensor. The ground on the sensor is typically made from the threads on the sensor. If you used teflon tape instead of paste you may have inadvertently disabled the ground path of the sensor.

Been there, done that, pealed back the Teflon Tape. :D

[michael everson]

Try jumping the wires at the sender and see if the gauge responds. If it does, its likely an issue with the sender. If not, look into the wiring at the gauge
Mike

[frankeeski]

Frank,
The fact that Chopthebass mentioned "supplied cable" leads me to believe that he is dealing with Speedhut/FFR gauges. If so they use two wires from the sender (ground and signal) and do not get their ground through the sender body. Indeed, the gauge has to be grounded (as well as have power and signal from the sender).




Jeff
No worries Kleiner, I did say typically. It'a all good. Good info from all so far.

[chopthebass]

Thanks guys.

Jeff, The water gauge sender is in the thermostat housing, and my EFi water temp sender is in the intake manifold (the right hand circle in this pic). The EFi programmer read the water temp ok, and triggered the cooling fan. I will try what Mike suggested - pull the wires off sender and join them. That's correct right?

http://i1252.photobucket.com/albums/hh562/cobra427427/Cobra%20Build/5b62da18-b8d4-4ea9-b376-1ba1a9713c61_zpsixqqzi7b.jpg (http://s1252.photobucket.com/user/cobra427427/media/Cobra%20Build/5b62da18-b8d4-4ea9-b376-1ba1a9713c61_zpsixqqzi7b.jpg.html)

[frankeeski]

Chop, If you've got the sender after the thermostat in the t-stat housing, it won't read right until the t-stat opens.

[chopthebass]

Thanks Frank. So can I 'T' it with the sender to the right in the pic? Or is there somewhere else I can put it?

The temperature gauge didn't move in the slightest though.

[frankeeski]

Thanks Frank. So can I 'T' it with the sender to the right in the pic? Or is there somewhere else I can put it? Can you get me a better picture of the front of the intake manifold and the stuff you already have plumbed there. It looks to me as if you may be able to get this fitting from Mark and make it work. http://www.breezeautomotive.com/details.php?prod_id=464&cat_id=17# The manifold I have has two ports in the top front of the manifold and the stock Ford heater t has a spot for the ECT sensor. I used the water neck port for the fan sensor since the engine has to come up to temp anyways before the fan kicks in. Just be careful how you orient the t fitting so the sensor has coolant flow. If not it still won't operate properly.

[j.miller]

No mater where you put it , it takes time...5-10 mins before the thermos opens and lets the flowing water transfer the heat. Been there ,done that. You let it run for a while then get nervous that something is not right then the gauge moves....next one is waiting for the fan to kick in.....wait for it......wait for it....da Bat

[NukeMMC]

Another option is to drill a 1/8" (or smaller) hole in the t-stat plate between the valve and the gasket sealing area to allow a small bit of water thru.

[chopthebass]

That Breeze part looks like the solution. Thanks guys

[chopthebass]

Update. I tried what my engine guy suggested - remove sender, and while connected, leave in boiling water. Did that for a few minutes and still no movement on gauge.
I tried what Mike suggested, jumping the two wires, and the gauge jumps to maximum. So am I right in assuming sender doesn't work?

[j.miller]

Sure sounds like it brother. Mikes way shows you the gauge is working. That sender should have jumped to 240.

[chopthebass]

So it gets even more confusing

This is what I have done so far:

tested resistance when cold, and it was 4.0
tested in boiling water and it rapidly decreased.
Joined the two terminals on sender plug and gauge went to maximum.

So it appears gauge and sender are both working. Any ideas what I can try now?

[CraigS]

Jury rig a new wire between the sender and gauge?

[chopthebass]

I can try that Craig, but I have checked the wire continuity and it seems ok.

[michael everson]

reverse the two wires. Pretty sure it matters
Mike

[chopthebass]

Mike, I will try reversing the wires.

I spoke to Speedhut and they gave me a couple more things to check. One was making sure that their pre-wired connectors have been done correctly!