My thoughts on the moving temp hands

[Robrt32]

I been running a after market temp gauge for a couple months now.. My temp moved a little 10 degrees 1 way or the other depending on the load.. I decided to hook the factory back up today while I was changing the fan blade. Its now back ALL over the place, from the N over to the M. Its a new sending unit, I guess it COULD be bad but the new one and my old one doing the exact same thing is unlikely... " I " think its just the way some of our older Sploders are gonna act..

 

[Robrt32]

I picked up the necessary T's and fittings to install a electric temp gauge in my heater hose.. I will now be able to compare both gauges.. I should get it done sometimes this afternoon.. I will post back the differences in each

 

[Maniak]

Keep us informed.

I notice that as the factory gauge gets higher it seems to move faster. 205F on the heater hose is between the A and L on my factory gauge. I also noticed it reads higher if the battery voltage is lower.

~Mark

 

[Robrt32]

Ok, this is twice Ive tried this and haven't gotten it right yet.. Its done got late and the skeeters made me quit today.. I got it all hooked up , the problem is the new gauge is showing 120 with the factory gauge sitting between the O and the R.. There is no way that is right, It has a 198 degree stat in it.. I mounted the T with the sender up,right before it goes into the heater core, all I can figure the water is pumping under it and not actually touching the bottom of the sender.. Maniac how do you have yours set up?

 

[Maniak]

We added a heater control valve to our 92, so it should be very similar to your 94.

It goes from the intake manifold to the adapter for the sending unit. From there it goes to the in side of heater control bypass valve. The rest of the connections should be the same as it was before you added the new sender. The out side of the heater control valve goes to the water pump and the other 2 ports on the heater control valve go to the heater (doesn't matter which lines goes to which port on the heater).

I used an infared (no touch) thermometer and measure the heater hose as it goes horizontal (before the sending unit) and it reads almost exactly the same as the aftermarket gauge. Don't forget to ground the adapter/sending unit as those sending units (1 wire) don't have their own ground.

Using the no touch thermometer I can see when the thermostat opens. The upper radiator hose temp will jump up to around 200F once it opens.

It just occured to me, you said you put it right before the heater. Your 94 should have a heater control bypass valve which means If you put it right by the heater, its not going to get hot water unless you move the heater/ac knob to heat (It may put it on other settings, but that one I know it will do it)

~Mark

 

[Robrt32]

I removed the heater by pass valve when I had to tie it open to get heat last winter so its not restricting the hot water.. I will move it to where it comes out the block, soon as I get as minute,, I did ground it to the body, maybe I need to ground it to the motor?

 

[Robrt32]

I just reread you post I grounded the gauge, Should modify a ground for the sender?

 

[Maniak]

If the sender only has 1 wire, it needs to be ground somehow, and through the coolant doesn't count. The adapter you have the sender in can be grounded.

On a friends f-150, which we installed an electric fan, we made our own adapter for the sending unit and we just used a hose clamp to hold a wire to the adapter (Next time we will make it cleaner).

~Mark

 

[Robrt32]

I fixed it this morning... I grounded it the same way you did, great minds think a like....



The results are.. When My factory gauge in on the O the new gauge says it 205 that is quite a bit of difference than yours