There is a two pin sensor and a single pin sensor in the driver side of the block behind the distributor. I figure the single pin is for the dash gauge and the two pin is for the computer. I do not have a computer or pretty much any of the electrical stuff that came OE on this thing.
Can I use that two pin temp sensor hole for a grounding temperature switch to control an electric fan?
Factory Service Manual Chapter 7 -17
It indicates the two pin sensor is for a TBD engine. Horizontal top pin for water temp and vertical pin for glow control.
I have a U engine which it indicates should have the single pin.
I have both sensors on mine. ??!! It has always been this way since I bought it and never bothered to wonder about it until now.
I guess this is one of the things left out of the manual.
You're correct. The single pin connector is for the temp gauge; the two pin is for the computer. If there's no longer a computer, the two pin is now nothing more than a hole plug. You could use that for a fan thermo-switch, but keep in mind that it is before the thermostat. Typically the sensor switch is after the t-stat, either near the top or the bottom of the radiator.Originally Posted by 85Ram50
Thank you. I wish I still had the thermostat housing that had the side hole in it. I forget what I did with it. I might go with that new thing I wired the fan in my Dakota with. A fitting in the hose from the thermostat to the radiator where you put the temperature grounding switch.
Here's an ebay listing for the housing with the side hole:
https://www.ebay.com/itm/32430446629...ampid%3APL_CLK
The in-hose fitting and switch should also work.
Bless you sir. I've been a lookin since I posted my reply to you.
Edit- Cost more to ship it than they are charging for it. Delivery by June 28. I'd rather not cut the top hose. I just put one in my Dakota and the hose clamps they included almost did not fit. And I have the moulded hose, so no straight section for it to fit in anyway. You need at least 4 inches of straight hose for it to fit right. Otherwise the clamps will start cutting into the hose.
Last edited by 85Ram50; 05-31-2024 at 03:51 PM.
Totally agree. Shipping is getting crazy especially from foreign suppliers. Here's an aftermarket model from a domestic supplier. Looks like it should work.
https://www.fleetpride.com/parts/mot...ssembly-ch6029
There are others that sell the MOTORAD CH6029, too.
I bought the ebay one.
That product page won't show for me. I just get the outline of the site. I was looking for the motorad when I came by your post yesterday. RA has it listed for the MM but it is out of stock. Every site said out of stock or NLA even Motorad site came back cannot find item.
6-8-24 got notice today that it shipped. only 20 more days
Last edited by 85Ram50; 06-08-2024 at 07:15 PM.
Well it showed up on the 11th.
I finally got out there and mounted the fan an after market Ford fan for an early 90's Continental, Taurus or Sable. part #35317 I didn't take pics yet. The battery side mounted right to the aluminium radiator where the OE shroud did. I had to drill. If you do it start small and increase size gradual. The plastic is brittle. The other side I had longer bolts and mounted from the OE shroud mount holes through the built in shroud on the fan (I added fender washers and a rubber gasket), which I had to cut out for the lower hose. I used that weatherstrip for doors where it is against the rad and where the cutout for the hose is just in case.
I got so excited I refilled the dam thing before I remembered I had not yet replaced the thermostat housing. So when the kit to control the fan comes in I will have to drain it again. On the ford fan the black is ground and the other two are low and high speed. I'm just going to run the high speed side. Since this thing runs so dang hot I chose a 190 on 175 off switch. I can always change it later.
What temp t-stat are you using? If you currently have the recommended 88C/190F t-stat, a 190/175 switch might be too low. As soon as the t-stat starts to open, the fans will switch on and run constantly. The 190/175 switch seems more appropriate if you're running an 82C/180F t-stat.
IDK which Tstat is in there. I'm thinking I may have gone with a 180 since it runs so hot. But I'll find out when I change the housing and act accordingly. I'm going to start a new thread for the electric fan install when it's done.
I received the wiring kit and the 1/8 npt sensor does not fit in the threaded hole in the housing from that link.
Anyone know what size that threaded hole is? part #MD061791
So far have not found specs on it. Added opic to show how far the 1/8npt sensor will go in for reference. That plug is what I took out of the hole and it was only a few threads in.
Over on DSM Tuners (Diamond Star Motors) they tell me it is 1/8 British Standard Pipe Taper. It definitely tapers.
1/8 NPT will have 27 threads per inch.
1/8 BSP or BSPT will have 28 threads per inch.
Last edited by 85Ram50; 06-25-2024 at 01:08 PM.
OK no luck finding any kind of BSPT grounding fan switch.
Went out to check my tap& die sets. both the metric and standard have a 1/8npt tap and die in them?! Anyway the die would not thread on to the sensor which is supposed to be 1/8npt. I ran it up it a few turns and stopped it was cutting the whole way. I'm hesitating now even though I know the thing should work if I drill out the hole tap it then run the die up the sensor and screw it in. Is there a concern with how much it sticks out into the flow?
AFAIK all tapered pipe threads on these trucks are BSPT, and you can get NPT-to-BSPT adapters. I got one off eBay to adapt a 3-terminal oil pressure switch (for electric fuel pump crash safety) to the standard block threading.
1987 Dodge Ram 50 4G54 RWD longbed ("Elmo")
1979 Lancia Beta Zagato spider ("Lola")
1982 Lancia Beta Zagato spider ("Luigi")
Maybe I am not understanding you?? I have seen the adapters. they would have the same problem of not allowing the sensor into them far enough to thread. Here is another pic to show the rest of that sensor. I never thought about it but the two pin and single pin temp sensors in the block looked like just regular NPT when I replaced them years ago.
EDIT- I have it apart got two new bolts for the housing. The old ones were thin at the top? I may have to shorten them a mm or two. IDK the size it was one of those places where a counter person takes your order or the bolt you brought in and gets your stuff. I didn't ask.
The Tstat is 180 and in good shape. If I still have a heat issue then it will have to be the rebuilt head I purchased from some guy back east who is out of business or possibly the intake is somehow clogged up. So I am probably just going to drill and tap it. I haven't committed to that yet but it looks like it is going that way.
Last edited by 85Ram50; 06-25-2024 at 04:34 PM.
It turned out to be very simple. I put it in the vise. got the 21/64 bit and it didn't even touch the threads it just cut the shoulder the manufacturing process left at the bottom of the hole. Then I ran a 1/8NPT tap into it far enough that when I screwed the switch in it was just far enough for the tip to be in the flow.
here is the housing with the shoulder drilled off, the smooth spot and with the sensor screwed in loosely.
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