Roadster builders - Speedhut + Ron Francis? Need help figuring out wiring

[David Hodgkins]

Hey guys,

I thought Id' break this out into it's own thread. Who here has experience hooking the speedhut gauges into the Ron Francis wiring harness? My gauge harness was made for the Autolights and I don't know how (or if) to wire the sensors and gauges into the harness. For example, how does the fan work if speedhut is using the sensor for water temp? How does the Ron Francis harness tell how hot the coolent is to actuate the fan?

How do you integrate the fuel level?

Stuff like that. I need help!

[edwardb]

You're not the first to note the pretty poor instructions for the Speedhut gauges. The RF schematic is pretty straightforward, and the Speedhut instructions aren't bad either. But marrying the two together isn't very intuitive. So here's the short answer to your question. First, the temp gauge and the cooling fan circuit are completely separate. Don't think of them together. The temp gauge gets hooked up with a designated wire just like all the other gauges e.g. oil pressure, tach, fuel gauge, etc. Nothing in the Speedhut gauges or instructions involve the cooling fan. As shown in the RF schematic, it's not automatic. It's a manual switch turned on/off by the driver. There are several ways to add a sensor to make it automatic.

Two key points about the Speedhut gauges. (1) They have two lighting circuits. One for backlighting, and one for the needles. Both get wired to the RF gauge lighting wire, but you will have two sets of wires connecting all the gauge lighting. The Speedhut gauge kit contains all the short daisy chain connections for this. (2) The RF schematic shows one wire for all the gauges, e.g. the signal wire. All the Speedhut gauges and sending units use two wires. One for signal and one for ground. So you just need to make sure this second wire is grounded in all cases.

Those are the basic principles. Maybe this helps? The next step would be point to point with colors, etc.

[rmiller64]

Hi David

Just finished up my wiring last month and found Jeff Kleiner's post very helpful

Quote Originally Posted by Jeff Kleiner View Post

The Speedhut/FFR Classic gauges use 2 wire senders while the RF harness is set up for one wire. You can use some of the redundant or unused wires in the harness for the second conductor but I recommend doing kind of a hybrid incorporating the long Speedhut pigtails. You'll need to power up all of the gauges on their red wire by connecting them to the brown "gauge feed" wire in the harness. Also connect the black "ground" wire in the dash harness to each of the gauges' black wires. You will carry the tachometer signal from the coil on the purple "coil-tach" wire that runs all the way through in the sending units subharness. The speedo signal comes through the green and gray wires which will join the yellow/red and yellow/black wires on the gauge. Polarity is not important as it is only counting pulses. For the coolant temperature and oil pressure gauges run the pigtail with the yellow/red and yellow/black wires to their respective senders. Once again polarity is not an issue because these are simply reading resistance. The voltmeter has no sender, the gauge power and ground give it all it needs. Fuel gauge connects to the light green "gas sender" wire. I recommend powering the clock from the red "radio memory" wire. That will get everything working!

Next move on to gauge lighting and their daisy chain. The white wire from all of the gauges connects to the RF harness white "dash lights" wire. If you have the seperate dimmer module the white harness "dash lights" wire connects to the input of the dimmer; the dimmer's black ground connects to the black harness ground. From there the dimmers output snaps into the connectors for the lighter gauge wire. It seems redundant but is this way because the needles are lighted independently from the gauge face and are not dimmed. If you do not have the dimmer module then the small white wire at the end of the snap together chain also connects to the harness white "dash lights" wire. By the way, before you drive yourself crazy thinking something is wrong... the hands on the clock are not lighted.

As for the ignition, I believe all of the ring connectors should be labled but if not:

---Red "headlight switch feed" and red "ignition switch/solenoid" wires go to the switch's "BAT" terminal
---Brown "accessory feed" and brown "alternator ignition" wires go to the "ACC" terminal
---Orange "ignition feed" wire goes to the "IGNITION" terminal
---Light blue pair "EFI crank" & "ignition switch/neutral start switch" goes to "START" terminal

Hope that helps get you moving and good luck!

Jeff

[DaleG]

David, this tutorial from Jeff Kleiner may help also:

OOps, I see Jeff posted it above.
Cheers, Dale

[Jeff Kleiner]

David,
Rick posted some of my instructions above. Here is a thread where I included some other details including my preferred way of dealing with the cooling fan (note that whether you use my method with a Painless non-grounding switch or the FFR/Ron Francis grounding switch there will be 2 sensors---one for automatic fan control and one for the temperature gauge).

http://www.ffcars.com/forums/17-fact...-question.html

Hope that helps; feel free to give me a shout if you need to

Jeff

[David Hodgkins]

Jeff I'm trying to wire this up using a 2 post thermo switch to start the fan automatically and it's not working. I'm wiring one of the wires to the orange fan switch wire and the other to the brown gauge feed wire (harness wires). I've got the thermo fan switch wire from the sending harness attached to the orange wire. What am I missing?

[Avalanche325]

Here is a different way to look at the fan wiring that might help. To turn the fan on what you need to do is complete the ground connection on the primary (control) side of the relay. In the harness, this is done with a switch on the dashboard. The temperature sensor is also just a switch. So just put those two switches in parallel and either one will close the relay. Grounding can be anywhere. Behind the dash or on the block and it is electrically the same thing.

[Jeff Kleiner]

David,
You have to ground the green "Fan Thermo Switch" wire. It makes the ground for the fan relay---without ground the relay will not work.

From the RF harness installation manual:

Electric Fan
 There are two ways to run the electric fan, use a dash switch to turn it on and off and keep an eye
on the water temperature gauge or, use a thermostatic switch to turn the fan on at 185° and off at
around 150°. The harness has been set-up for both ways.
Switch controlled
Ground the sending unit wire marked “Fan Thermo switch”.
Connect and attach the fan switch as instructed in the dash wiring section...

The Painless switch is a non-grounding ON/OFF switch whereas the one included with the kit is a grounding switch---that's what trips people up. When using the Painless switch you wire it as if you were ONLY using the dash toggle. The Painless switch is then piggybacked in parallel.

Soooo, let's back up, forget all about the thermo switch for a minute and first make it work with the dash toggle:
---Ground the green "fan thermo switch" wire that is in the sending units/electric choke branch of the harness.
---Go to the dash harness and find the brown "fan switch feed" and orange "cooling fan" wires.
---Connect the brown to one terminal of the toggle and the orange to the other terminal.
---You have two essential harness grounds---both are black wires with ring terminals labeled "ground"; one comes from the brown plug on the front harness and the other is in the main harness. Assure that both are landed to clean secure chassis grounding points.
---Plug in the cooling fan, turn on the key and it should work!

To incorporate the Painless switch take a pigtail from the brown wire at the toggle and run it to one terminal of the thermostatic switch. Take another pigtail from the orange wire at the toggle and run it to the other terminal of the Painless switch.

If you want to have an indicator light to show you that the fan is energized by either source run yet another pigtail from the orange wire on the toggle to one terminal of the lamp. Take a wire from the other lamp terminal to ground.

All of this will allow you to turn the fan on manually or allow the Painless switch to do so when the coolant temperature reaches it's activation point. In either case the light will come on when the fan relay is energized.

Hope that helps!

Jeff

[David Hodgkins]

OK Jeff, back to the drawing board, so to speak. I'll try your suggestions above this afternoon...

[David Hodgkins]

Well Jeff, I gotta say, you know your stuff. I got the manual switch working yesterday and will hook up the thermo switch today.

A few of the instructions you've given didn't work with my setup (minor stuff, like the volt gauge needed to have it's sender attached to 12+ in order to work) and I'll be doing a more comprehensive FYI post to document the Ron Francis / Speedhut setup. It's still a work in progress because my tach is VERY jumpy and inaccurate but I'm sure I'll figure it out, probably with your help.



Thanks again!

[Jeff Kleiner]

Good to hear David. I've not encountered a Speedhut volt gauge with a sender, only input power???? RE: the tach; check your Speedhut literature---some of the tachs have a small wire loop on the backside which they instruct you cut to help stabilize jumpy readings.

Jeff

[David Hodgkins]

Jeff, remember, my gauges are 5 years old!

I'll check the back of the tach. It's not wired as you suggested in another post; I used the sender wires to hang off the coil directly and didn't use the purple wire from the RF sender harness...

[ehansen007]

I'll be sure to have you over when I wire the 289.... It will still be fresh.

[David Hodgkins]

This weekend I spent some time trying to get the thermo switch to work and failed.

"To incorporate the Painless switch take a pigtail from the brown wire at the toggle and run it to one terminal of the thermostatic switch. Take another pigtail from the orange wire at the toggle and run it to the other terminal of the Painless switch."

This didn't work. It's not a painless switch, it's a thermo switch I got at the parts counter at Ford. The way it's put together I don't understand how the thermo switch can switch the power to the fan on. I did exactly as described: I took each wire from the toggle switch and tied it in to the wires on the thermo switch. I can still turn the fan on by flipping the switch but after letting the motor warm up the fan didn't kick on automatically.



EDIT: It did cut the looped wire on the back of the tach and that "calmed it down". Thanks for the tip Jeff.

[edwardb]

This weekend I spent some time trying to get the thermo switch to work and failed.

"To incorporate the Painless switch take a pigtail from the brown wire at the toggle and run it to one terminal of the thermostatic switch. Take another pigtail from the orange wire at the toggle and run it to the other terminal of the Painless switch."

This didn't work. It's not a painless switch, it's a thermo switch I got at the parts counter at Ford. The way it's put together I don't understand how the thermo switch can switch the power to the fan on. I did exactly as described: I took each wire from the toggle switch and tied it in to the wires on the thermo switch. I can still turn the fan on by flipping the switch but after letting the motor warm up the fan didn't kick on automatically.



EDIT: It did cut the looped wire on the back of the tach and that "calmed it down". Thanks for the tip Jeff.

The recommended Painless switch (#30110 or 30111) are a type of thermal switches, each with difference on/off heat ranges. But they are a simple on and off switch. They have two terminals. The two terminals are open until the target on temp is met, then they close completing the circuit and starting your cooling fan. Same as the manual switch on your dash. When the lower temp is met, they open back up turning off the fan.

Does the sensor you bought have one terminal or two? Many are only one terminal, and when closed are switching to ground. Another way to work the circuit but not how this one from Jeff (which I also used) works. Also, do you know the rated heat range for the Ford switch you bought?

On a side note, I'm actually looking for an alternative to the Painless switches. They are, unfortunately, not very accurate. I have had several of both part numbers, and the on and off points measure quite different than how they're rated. I've been back and forth with Painless tech support over the past week or so. They measured all the ones they had in stock and they also were quite a bit off. Like 10-15 degrees. I suggested they either needed to change the ratings or talk to the manufacturer (marked made in Taiwan) and tighten them up a bit. No response on that one. Similar negative reviews on the Summit website.

[David Hodgkins]

Hi Edward, thanks for chiming in. It's a two-terminal switch. I thought it said 175-155 but I'll check. Is there a way to test? Just put it in boiling water and see if I get continuity across the terminals?

[edwardb]

Hi Edward, thanks for chiming in. It's a two-terminal switch. I thought it said 175-155 but I'll check. Is there a way to test? Just put it in boiling water and see if I get continuity across the terminals?

Yep, that's what I do. I hang them in a pan of water on the stove with a continuity light across the terminals and a temp probe off my VOM in the water next to it. Turn on the heat and watch what temp it closes. Turn off the heat and what what temp it opens. Similar to how I test thermostats, just without the continuity light. Just watch them open and close.

Just for grins, do you have the part number of the Ford part you have?

[Jeff Kleiner]

I gave you a part number and instructions on how to make it work; I can't guarantee that it will operate the same if you trying to use something different... Are you certain that it is a true on/off switch and not a just sender for one of Ford's notorious "idiot gauges" (their dashboard gauges are often just a glorified idiot light that puts the needle in the "normal" range across a wide temperature or pressure spectrum and doesn't really accurately report either)? If that's the case you'll see resistance change as the temperature does whereas a switch will be either open or closed.

Jeff

[David Hodgkins]

Jeff, 30110 ordered today, coming in tomorrow.

[David Hodgkins]

The painless thermo switch came in - those suckers are expensive!


I didn't have time to install it until yesterday. The wire connectors that came with the switch were for very small gauge wire so I decided to pull the wire I used for the first switch and replaced it with thinner wire, since it only has to indicate switch position and isn't carrying a load. I further decided to just connect the wires to the orange thermo switch wire and brown gauge feed wire, and removed the manual toggle switch. I drained some water from the cooling system and removed the ford part and replaced it with the new painless part, fired up the go cart and took some short trips around the parking lot. For the first trip I actually went into the street and there was a man in blue writing a ticket a block down so I quickly abandoned that idea! After a few minutes the gauge was reading 90 degrees celsius so I parked it and let the motor warm up a bit more...


... and the fan flipped on! YES! I now have a working go cart!

Today I dieted the sender harness and took all the wires out except for the green Fan Thermo Sw(itch) wire. I cut it down and grounded it with the main harness ground. All the other senders are run to the Speedhut gauges directly. The pics below show...

The plug before dieting:


...and after dieting:


The wire saved:


And it's final route:


Here's a pic of the removed wires:

[Jeff Kleiner]

Jeff

[stevant]

Hi David

Just finished up my wiring last month and found Jeff Kleiner's post very helpful

Quote Originally Posted by Jeff Kleiner View Post

The Speedhut/FFR Classic gauges use 2 wire senders while the RF harness is set up for one wire. You can use some of the redundant or unused wires in the harness for the second conductor but I recommend doing kind of a hybrid incorporating the long Speedhut pigtails. You'll need to power up all of the gauges on their red wire by connecting them to the brown "gauge feed" wire in the harness. Also connect the black "ground" wire in the dash harness to each of the gauges' black wires. You will carry the tachometer signal from the coil on the purple "coil-tach" wire that runs all the way through in the sending units subharness. The speedo signal comes through the green and gray wires which will join the yellow/red and yellow/black wires on the gauge. Polarity is not important as it is only counting pulses. For the coolant temperature and oil pressure gauges run the pigtail with the yellow/red and yellow/black wires to their respective senders. Once again polarity is not an issue because these are simply reading resistance. The voltmeter has no sender, the gauge power and ground give it all it needs. Fuel gauge connects to the light green "gas sender" wire. I recommend powering the clock from the red "radio memory" wire. That will get everything working!

Next move on to gauge lighting and their daisy chain. The white wire from all of the gauges connects to the RF harness white "dash lights" wire. If you have the seperate dimmer module the white harness "dash lights" wire connects to the input of the dimmer; the dimmer's black ground connects to the black harness ground. From there the dimmers output snaps into the connectors for the lighter gauge wire. It seems redundant but is this way because the needles are lighted independently from the gauge face and are not dimmed. If you do not have the dimmer module then the small white wire at the end of the snap together chain also connects to the harness white "dash lights" wire. By the way, before you drive yourself crazy thinking something is wrong... the hands on the clock are not lighted.

As for the ignition, I believe all of the ring connectors should be labled but if not:

---Red "headlight switch feed" and red "ignition switch/solenoid" wires go to the switch's "BAT" terminal
---Brown "accessory feed" and brown "alternator ignition" wires go to the "ACC" terminal
---Orange "ignition feed" wire goes to the "IGNITION" terminal
---Light blue pair "EFI crank" & "ignition switch/neutral start switch" goes to "START" terminal

Hope that helps get you moving and good luck!

Jeff

I know this is an old thread but figured I would ask to hopefully get a response. I have done everything as stated above yet the dimmer on the headlight switch will not dim the dash. The dimmer on the RF harness (On the daisy chain behind dash)works fine but the one in the headlight switch....nothing.

Anty ideas?...am I missing something?

[Jeff Kleiner]

What you're seeing is normal; the headlight switch dimmer is redundant and won't do anything to the gauge lighting when using the Speedhuts and their inverter/dimmer.

Jeff