Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Put electric fans in my truck to replace the mechanical fan, and the spot I want to put the temp switch for triggering the fan relay is threaded M10x1.0, straight thread. I've just spent several hours browsing through the catalogs of Standard Motor products, Echlin, BWD, Four Seasons, etc, and found that virtually none of their products have published thread size information on them, and calling them up results in the same blank stare I get from the parts stores guy - "uhh...year make and model??" The only thing left stock on my truck at this point is the frame, sheet metal, and part of the interior...
Ideally I'd like an adjustable controller set up, but I'd take a fixed switch with on/off temps somewhere around 200F/185F...but short of finding a parts store that's willing to let me check every switch on their shelf...I'm coming up a bit short here.
This place is for posting questions on how to stay awake at the wheel and other matters of grave concern. Finding fan switches with M10x1.0, the straight thread is way over our heads.
1) Why don't you just buy the switch that's for your engine? Or is this not a location that was originally the mounting for a temperature switch?
2) Make up an adapter with OD M10 thread and ID whatever your switch has. M10's pretty big so you may be able to use a simple "bushing" type part. Install with heat sink compound.
Says not for temp sender use? I suspect the ID isn't bored large enough for the sender tip to poke through, and likely can't be while still maintaining sufficient strength?
Quote:
Originally Posted by HappyRider
This place is for posting questions on how to stay awake at the wheel and other matters of grave concern. Finding fan switches with M10x1.0, the straight thread is way over our heads.
Yeah...that thought crossed my mind too...but I figured it would be the best way to get a cross section of people that are familiar with far more than just one vehicle or type, lol.
Quote:
Originally Posted by turf3
1) Why don't you just buy the switch that's for your engine? Or is this not a location that was originally the mounting for a temperature switch?
2) Make up an adapter with OD M10 thread and ID whatever your switch has. M10's pretty big so you may be able to use a simple "bushing" type part. Install with heat sink compound.
M10 really isn't...it's really close to 1/8" NPT, whereas the vast majority of temp senders/switches are either 3/8"NPT or 1/2"NPT, which is absolutely massive compared to 1/8"NPT or M10. In fact, M10x1.00 is so close to 1/8"NPT that a lot of guys just run a 1/8"NPT sender right into an M10 threaded port and it works OK, or run a 1/8"NPT tap into a M10 threaded port, which also works OK.
My issue/concern though is that yes, it's not the factory location. Typical senders/switches for these engines (Gen 1 small block Chevy) are typically either 3/8"NPT or 1/2" NPT, but I want it on the cold side radiator tank where there is a preexisting bung on the aftermarket aluminum radiator....that's M10. China's finest! I don't have any other locations on the motor that aren't currently being used for other functions, and I don't want to pull the motor apart to drill/tap another port.
I'm also concerned about modifiying the existing bung, or trying to run a 1/8" switch into it....it is Chinese aluminum after all. I don't want to find out the hard way that using anything other than a M10 switch will overstress the aluminum, lol. Realistically, I'm probably going to pull the radiator, and just weld in a 3/8" NPT bung into it for this, but I was hoping there would already be something off the shelf.
2) Make up an adapter with OD M10 thread and ID whatever your switch has. M10's pretty big so you may be able to use a simple "bushing" type part. Install with heat sink compound.
Problem with bushings on things like coolant or temp sensors is the bushing raises the hight of the sensor slightly. It might be far enough away that a pocket of stagnant, cooler coolant may build under the sensor and cause incorrect readings.
You really want the sensor to be down as far as you can get it in the coolant flow, meaning a direct thread in.
but I want it on the cold side radiator tank where there is a preexisting bung on the aftermarket aluminum radiator....that's M10. China's finest! I don't have any other locations on the motor that aren't currently being used for other functions, and I don't want to pull the motor apart to drill/tap another port.
Sounds like you have two problems then. First is finding am M10 temp sensor (which I don't think exist as i'd imagine they all use taper threads) but second problem is getting one in the correct temp range you need to activate the fan.
When you are at 200F on the cold side of the radiator, what temp are you at the engine? 210? 220? You might need a temp sensor that actually comes on at 190F to compensate for the temp differential at the radiator vs the engine.
Sounds like you have two problems then. First is finding am M10 temp sensor (which I don't think exist as i'd imagine they all use taper threads) but second problem is getting one in the correct temp range you need to activate the fan.
When you are at 200F on the cold side of the radiator, what temp are you at the engine? 210? 220? You might need a temp sensor that actually comes on at 190F to compensate for the temp differential at the radiator vs the engine.
There are sensor fittings on M10 straight threads. They seal with either an O-ring or crush washer. I've seen a handful in the catalogs, but as far as the switches go, they are listed at switching at either way high or way low temps...such as closing at 250*F or 100*F, and they're all on OEM style connectors. The few I could find to actually purchase were also around the $100 price point, before even trying to source the connectors.
As far as the temp differential, this is why I ideally want an adjustable controller. Although realistically, I'm not going to see a major difference in engine temp vs radiator cold side if the temps are rising enough to kick on the fans, as this means that I'll either be stopped, or moving slow enough to not be passing much air over the radiator. Sure, there will be some heat released via convection as it travels through the hoses and radiator, but not enough to make a significant difference.
Though it also occurred to me earlier today that I've got enough aluminum stock sitting around the garage that I could just make an adapter fitting for the lower radiator hose to shove a standard temp sensor into.
Are you stuck with the M10 hole? If you can change that, and I assume you are on the cold side of the radiator, for example the switches for old 1980's water cooled VW systems are common, the threads are a good bit bigger than M10.
You could indeed put an adapter in the lower radiator hose, that might be simpler.
The common VW system has a 3 prong switch, for 2 fan speeds (one through a resistor, one straight 12V)
Typically, aftermarket electric cooling fans, such as Flex-a-Lite, have a thermal switch that is in contact with the radiator cooling-fins; it looks like a copper bulge, around 3/8" in diameter. So, one option is to adopt this method.
If you prefer measuring temperature directly at the block or heads, via a screw-in fitting, a couple of options present themselves. One is to get a brass (probably) fitting in the native diameter and thread pitch. Assuming that this is sufficiently larger than M10, you can drill and tap this fitting to accept the M10 fitting belonging to your cooling-fan kit. Alternatively, you can use the OEM sensor and splice its wires into your new system. If your difficulty is the reverse (the OP is a bit cryptic), wherein you need to find a M10 bolt of some particular length, try McMaster-Carr. They have everything.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I don't have any other locations on the motor that aren't currently being used for other functions, and I don't want to pull the motor apart to drill/tap another port. 
