Should radiators be grounded?

dang

dang

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I just realized last night that the temp sensor I got is a single wire/terminal, which means it grounds through the case, which means it won't work on our style radiators. Correct? The sensor bung is in the lower section of the radiator. I suppose a ground strap to the radiator would work but that would be kinda shade tree. I'm assuming a two-wire sensor is a must.

Or, should ALL aluminum radiators be grounded? :cool:

IMG_20210521_131802187.jpg
 
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In general, is there any advantage to sensing off the engine rather than the rad? Intuitively I would think getting ahead of the curve and turning on the fan when the engine is hot would be better than waiting for the rad to heat up and then turning it on. Also, the bottom of the rad is the coolest point in the cooling system. If sensing off the rad I would think sensing off the top would be more effective.

Is there another bung on the engine that could be used for the sensor?

If not, I've successfully used the probe type sensor that is inserted between rad fins. Example...

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Mishimoto Adjustable Radiator Fan Controller Kit, Probe Style

Take full control of your electric cooling fan with the Mishimoto Adjustable Fan Controller Kit! This kit is applicable for any 12v electric fan and includes all necessary components for installation. This kit includes a probe sensor to fit the needs of any project. The Mishimoto Fan Controller...
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In any case I'd use an adjustable sensor so you can dial in when the fan comes on relative to actual engine temp.
 
Thanks Dick, but will a one wire sensor work on my radiator?

One more bung hole but only slightly higher on the radiator. Nothing else on my engine to use.
 
Good point. I guess the probe type sensor is still looking for a ground through the rad.

Maybe do a test with a test light. One terminal to the + post on the batt and the other to the rad and see if the light lights. If you are getting a ground through the rad then you can use one of the rad bungs and a one wire sensor or the probe type. I would still use an adjustable sensor so that it will turn on the fan when the engine temp wants it on.
 
I used a short ground wire on mine from the sensor to the body
 
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dang said:
Or, should ALL aluminum radiators be grounded?
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I don't see any reason to ground a radiator (other than to make your fan sensor work electrically). Whether the radiator is brass or aluminum wouldn't matter. Is your concern electrolytic corrosion? As long as the coolant has rust inhibitors, you should be OK. The iron block - aluminum head engine is more susceptible to corrosion than the radiator.
 
jmackro said:
I don't see any reason to ground a radiator (other than to make your fan sensor work electrically). Whether the radiator is brass or aluminum wouldn't matter. Is your concern electrolytic corrosion? As long as the coolant has rust inhibitors, you should be OK. The iron block - aluminum head engine is more susceptible to corrosion than the radiator.
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I've heard that grounding a radiator can reduce corrosion but I've never researched it. The head and engine components are all grounded.
 
dang said:
How did you connect to the sensor?
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I found a large enough electrical ring connector that would slip over the threads of the sensor when installed (with thread sealer) into the radiator which I had crimped and soldered a wire to with another connector on the other end of the wire. The rubber feet of the rad supports will prevent adequate grounding for a sensor otherwise.
 
I was an art major so I’m no expert but, doesn’t the water/coolant function as the conductor to the grounded engine block?

- S
 
3moons said:
I was an art major so I’m no expert but, doesn’t the water/coolant function as the conductor to the grounded engine block?

- S
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This is what I read, but I'm not sure how well. I suppose a few tests would help. This may also be related to the corrosion aspect of it and whether grounding helps..
 
For lower radiator installs.
wiring easy by running fused green wire from coil

82* C is 179* F
 

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Single wire fan switches go best in thermostat housings which are grounded to the head.
if you change to this “A“. housing you will need the later thermostat and some
screw plugs
 

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I too have a single wire sensor and had thought that the coolant would enable the ground.

And I have grounds from my battery to the body, from my alternator to the block, from that same point on the block to the place where my battery is grounded to the body, at the top of the transmission to the body and across one of my motor mounts to the front subframe.
 
dang said:
This is what I read, but I'm not sure how well. I suppose a few tests would help. This may also be related to the corrosion aspect of it and whether grounding helps..
Click to expand...

Mine would not work without being grounded, perhaps the voltage/current is not enough to conduct through water since it doesn't conduct as well as metal. I would think with a sensor you're going to want the least resistance possible for accuracy.
 
sfdon said:
For lower radiator installs.
wiring easy by running fused green wire from coil

82* C is 179* F
Click to expand...
This setup was the most interesting to me because of the wiring. Does this type of sensor/thermostat switch eliminate the need for a relay?

s-l500.jpg
 
I stand corrrected.
sfdon said:
For lower radiator installs.
wiring easy by running fused green wire from coil

82* C is 179* F
Click to expand...


I have a relay in my circuit. I have switched power to terminal 85 and a wire from terminal 86 to a tstat type switch. Thus, my switch wired as a ground switch. I'm thinking this switch could be swapped in its place, using a ground wire from one terminal to the body. This way it would ground to the car, instead of through its body as the tstat switch (which I have installed now) does.

Does this make sense?
 
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