Factory Five Racing Forum banner
1 - 20 of 27 Posts

· Registered
Joined
·
4,738 Posts
Discussion Starter · #1 ·
An Electric Fan Thermostat Sending Unit and a Bosch type relay.
I went to O'Reilys and Autozone and didn't have any luck with the relay and got the wrong coolant switch. The problem was I couldn't tell them what year and model they came off of (that drives me crazy when they ask that).

If someone could tell me the correct name or product number, I'd really appreciate it.
Electric Fan Thermostat Sending Unit, came from my '93 302 intake (I believe it's and Explorer intake), but we couldn't find it in their system. It has 2 very small blade type connectors in the top. The one we found had too small threaded section (the bore in the intake was larger).


I'm getting ready to setup my headlight wiring and think this is what I'll need based on this diagram. I asked for a Bosch Relay, but they didn't know what I was talking about and asked me what car it came out of.
 

· section 8
Joined
·
5,135 Posts
looks like a generic 5 pin relay, search the switch on the napa site under the vehicle the engine came from . Not surprised the parts couldn't be found without knowing what it came from, good help is hard to find . Try Fan control switch , cooling fan switch etc. Hopefully someone can be of more help
 

· Registered
Joined
·
926 Posts
These are simple 12V five pin relays. Unfortunately, most parts houses are a computer base supplier and they don’t really know about stuff like this unless they can look it up by year, model, and such. That’s just the way our society has turned these days. Can’t really blame the parts housed.
I just got a couple of these in about three weeks ago. I’m at work right now, but can get you the info on these when I get home. The ones I ordered came with the plugs and wire leads (about 5 inches long) I will post these this afternoon.
 

· Senior Charter Member
Joined
·
1,874 Posts
The type of relay you are looking for you should be able to find at Autozone or any number of other parts houses by going to the generic electrical parts shelf. I know my local Auotzone has a variety of relays, thats where I got the ones for my car.
As for the temp switch, if you are looking for one to fit into a very specific system then you'll need to give the guy behind the counter something to go on to find the right one. There are probably hundreds of numbers for as many different cars. If you are putting it into a system that never had an electric fan like mine you can find a generic one at Summit or other places like that. They will list them by thread size and temp on/off ranges.
 

· Registered
Joined
·
4,738 Posts
Discussion Starter · #5 ·
I pulled the old temp sensor off of my car and will take it to O'Reilys this morning and see if I can match it up. We looked up '93 Mustang intake and didn't find any listed, then looked at '96 Explorer intakes and found one, but it was too small.

For the relay, we did look in the electrical parts section of the store, but could not find a 5 prong relay at either store.

I'm going to keep looking.
 

· Registered
Joined
·
1,267 Posts

· Registered
Joined
·
1,267 Posts
and found one, but it was too small.
For that are adapters there...Home depot. These are all NPT based - so no problem if they are smaller than the intake hole...

 

· Registered
Joined
·
4,498 Posts
Mark, get one from.....RF part # AR-33 or AR-34
i believe i just used the painless for my fan it is a 2 spade connection

another option go to Ford dealer most parts guys will find it for you, Sunset or Dave sinclair near by, the Dave guys have a better personality

check out radio shack for the relay. don't you have relays in that massive harness you put in.........should be
 

· Registered
Joined
·
2,056 Posts
The sensor you get here...
Sensors
Ok, maybe I'm confused, but here goes-

In the first post he's looking for an electric fan sending unit. For a vehicle that *I think* never had an electric fan (could be wrong).

The sensor he has pictured is a pretty standard looking Ford unit, which is almost always a thermistor going to the ECU (a thermistor can't / won't operate the fan directly).

If he's looking for a thermostat switch to operate the fan then he needs to being looking at something like this, there's nothing on the linked Speedhut page that will do what (I think) he wants to do:

http://www.summitracing.com/parts/sum-890017

HTH, but I'm not sure I'm following along. All the relay info looks Ok.

Mike

P.S. BigLeos' RF part numbers do the same thing as the Summit (which is what I think he wants to do on the fan).
 

· Not a waxer
Joined
·
12,099 Posts
I'm with Mike. Neither the '93 Mustang or Explorer used an electric cooling fan. I think you are looking at the engine coolant temp sensor that reports to the ECU (although the OEM ones are usually pointed on the end). If uou can show us the end that recieves the connector it might help i identify it as all Ford plugs are unique to the switch or sensor.

Jeff
 

· Registered
Joined
·
4,738 Posts
Discussion Starter · #11 ·
Mike & Jeff, thanks! That makes more sense.
ok, well that would certainly explain why I can't find it! I returned the old one to O'Reilys this morning and we spent 20 minutes trying to find the Electric Fan Thermostat Sending Unit and none of the Ford items fit! Might also explain why my fan would kick on immediately and not shut down when it got down to temp. (I just thought it was stuck open)

Hmmm, (now I need to go check where I connected the ECU again :confused:)
OK, so I'll start from my requirements then. What should I be using to control the fan? (I know the originals didn't have an electronic fan).
So how does this one work? Completes the ground? I'll need to re-think my wiring, I had it completing the hot, triggering the relay.
Summit item from Mike's link:



couple pictures of the other end of what I thought was the sending unit.


 

· Registered
Joined
·
2,056 Posts
Yes, the Summit one completes ground - you ought to use it to give the fan relay a ground, use the 30A contacts on the relay to power the fan (that's the point of using a relay, the contacts in the switch wouldn't last long under that load).

And yes, the Ford sensor still looks like a thermister, I'm suprised the fan would run at all. The thermistor changes resistance with temp, they're usually up around 1000 ohms and higher (across the two terminals). The contact on the Summit for instance should read open (infinity) at room temperature, and closed (0 ohms) to ground above ~175-185 degrees F.

Mike
 

· Registered
Joined
·
2,056 Posts
P.S.

Hmmm, (now I need to go check where I connected the ECU again :confused:)
IIRC, my 1990 Bronco (351w) had two water temp thermistors going to the ECU... I think one of them was mainly a control point for the EGR valve - it caused stalls at idle once the motor was warm (bad thermistor), took a long time to figure out.

On the other hand it may have been one for the stock gauge and the other for the ECU, can't remember.

Just something to keep an eye on while you're digging around to figure out what you hooked up + why.

Mike
 

· Registered
Joined
·
4,498 Posts
maybe this might be the part, i bought it for my 93 f-150 didn't use it.
cross reference the number i got it at O"rieleys'
BWD engine mangement technology part # PT309
its a sensor and i got the pig-tail for it too

its yours if you want it
brand new still in the box
 

· Registered
Joined
·
2,056 Posts
maybe this might be the part, i bought it for my 93 f-150 didn't use it.
cross reference the number i got it at O"rieleys'
BWD engine mangement technology part # PT309
its a sensor and i got the pig-tail for it too
That PN shows up as a pigtail for a thermistor / transistor type coolant temp sensor for the ECU.

The sensor PN associated with that pigtail is WT5058.

So it's an ECU sensor, not for running the fan.

Just so we're all clear... :icon18:

Mike
 

· Registered
Joined
·
1,267 Posts
The top one is the original Ford sending unit. That unit, like many Ford, has 3/8 NPT. The bottom one is the speedhud unit. Both work fine with my 2000 CPU to control the fan.
I have to use them both because, while the water temperature gauge is hooked at the same circuit the CPU gets a incorrect reading. I thought I get away with one - but nah...





Now you showed a picture of the connector - the speedhud may or may not fit.


 

· Registered
Joined
·
1,267 Posts
Yes, the CPU senses the temperature from the sending unit and opens the circuit for the fan relay as needed. The fan relay is housed in the CCRM (Constant Control Relay Module).
 

· Registered
Joined
·
796 Posts
To control my fan i used what Jeff did to create an automatic switch with a manual override. I ordered one of those Painless switches and drilled/tapped the 90 degree thermostat housing for placement. This controls my fan, but it isn't tied up with the computer...is that what you are trying to figure out? Jeff's quote below is from another thred and his solution is using the Ron Francis Harness...

Don't let the fact that FFR packs a relay with the cooling fan components trip you up---that is simply ease of packaging on their part---you will not use that one. The RF harness already has a fan relay wired and in place in the fuse box beside the horn relay.

You want to make your fan operation easy and automatic? Wire it with the manual dash switch using the brown "fan switch feed" wire for power in and the orange "cooling fan" wire that feeds a switch signal to the relay. You'll find both of these wires are in the dash harness. If you want an indicator light (I like to use an amber one to show when it is on) tap one side of the lamp into the orange and take the other side to ground. Now, for automatic operation pick up a Painless thermostat switch. It is a true, normally open thermostatic switch with two female spade contacts, not a grounding switch. Wire it in parallel with the manual dashboard toggle; i.e. one side to the brown feed wire the other to the orange load wire. Screw it into a coolant port in the intake or thermostat housing and you're done; no reconfiguring of the relay as would be necessary with a grounding switch and the entire circuit is still protected by the 30 amp "cooling fan" fuse. Simple as that--- you will now have automatic as well as manual fan control and an indicator light to let you know anytime the fan is running! The Painless switch I used for "Indy 14" Steve's car is #30111 which is on at 185* and off at 175* (running a 180* stat) but there are others available with different on/off setpoints.

Hope that helps and good luck!

Jeff
 
1 - 20 of 27 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top