We got the first start in yesterday. It was awesome. The forte 427 fired right up and purred like a very loud kitten. Been trying to post a video unsuccessfully but I will figure it out. In any case - the first start was successful but a few problems I need to take care of.
1.) biggest issue is the fan didn’t turn on. I let her idle and get to 190 and with no fan kicking in had to shut down. I think I may have the fan wiring wrong. Essentially in the front harness there is a green thermo wire and blue water temp wire. I hooked the blue wire up to the fan hot which is what is shown in the wiring diagram from FFR. Should the green thermo sw be what’s connected here?
2.) my speedometer did not work. Needle just sat all way to the right. It was powered and is counting but not right. It’s connected directly to Speedo on trans. Not sure what I’m missing here. See pic for how i have it wired.
3.) voltmeter not working. Is there any efi I could or should wire to that instead? I actually don’t know where that gauge is currently pulling signal from or supposed to anyway. I just have it plugged into harness per instructions.
Assuming you're using the F5-provided RF harness...
For your fan: the dark blue wire goes to one side of the fan and then you ground the other side. Pay attention to which color goes to which side; the connector on the fan will help you here. If you wire the fan backwards it will try to blow instead of suck (it'll make sense when the fan comes on). There are two green thermo switch wires: one in the sending units harness that typically goes to the top of the engine, and one in the front harness that typically goes to the bottom of the engine. Connect ONE of those green wires to the thermo switch and cap the other for now (you can remove it later when you're happy with all things electrical). Basically what happens is the thermo switch gets hot, and switches the green thermo switch wire to ground. That in turn causes the fan relay to send power to the fan. Use whatever green thermo switch wire makes sense for your application.
You mention EFI; are you using that or carb? If EFI, do you want the engine control unit to also control your fan? Almost all EFI systems allow you to do so & provide an output wire that shunts to ground when commanded by the ECU. Read your EFI instructions to verify it sends a ground signal; you can burn something up if you connect power to a device that expects ground. For an EFI system that provides a ground output for fan control, connect the EFI fan wire to the green thermo switch wire and voila; the ECU will control the fan (and you can program it to come on at whatever temp you want). There is a downside to EFI controlling the fan, and that is you need a second sensor to feed your temperature gauge. You can't just piggy back the gauge off the sensor that drives the ECU.
If you're confident you've got the wiring correct & need to troubleshoot, I recommend starting with this thread: https://thefactoryfiveforum.com/show...my-cooling-fan. Papa gives excellent step-by-step instructions (and if he or edwardb weigh in on a thread pay attention; they'll steer you right every time).
For your speedometer: I'm assuming that's the F5-provided GPS driven gauge from Speedhut? If so, I have no experience with that gauge and can't help you.
For your voltmeter: I'm assuming again it's the F5-provided gauge from Speedhut? If so, connect the single yellow wire from the back of the gauge to the brown gauge feed wire.
John
Last edited by phileas_fogg; 01-29-2024 at 05:52 PM.
Thanks John - great feedback - very helpful. That other thread was very helpful as well. I’m a bit worried now though because I think I actually have it wired correctly reading your response. I attached a couple pics that might help shed some light on my assumptions. I have the water temp probe in an extension coming straight up from manifold connected to the blue wire in sending harness and the green thermo wire connected to the thermo switch which is installed directly in manifold above pump. I’m wondering if it might be the relay so I ordered an extra to test. My horn isn’t working either so could be same issue.
Can you let me know if anything looks off in the attached pics?
What temperature of thermostat are you running? The position of your thermo switch is after the thermostat and thus it will not sense a temperature increase until the thermostat opens. I ran mine this way before the Sniper installation with a 180 thermostat and a 200/185 thermo switch. This way the engine would warm to 180 and the thermostat would open and, if in traffic or moving slowly, the temperature would continue to climb to 200 and then the fan would come on. It would stay on until the temp reached 185 and shut off. Cruising down the highway the temp would be steady at 180 and the fan would be off.
You have teflon tape or some other sealant around your sensors. This is not recommended and may be preventing the sensor from properly grounding to the block.
You can test your wiring by turning the ignition on and grounding the sensor wire to the block. The fan should come on.
HTH
Norm
Mk4 base kit 7721, 331 Stroker, Holley Sniper EFI, Wipers, Heater, Whitby Soft Top, Drop trunk mod and more
As Norm says "You can test your wiring by turning the ignition on and grounding the sensor wire to the block. The fan should come on." So take the spade connector off the thermo switch & touch the connector to your block. If all is well with the wiring, the fan should come on.
But if your horn doesn't work either, that smells like a related problem. Do your brake lights work? Do you have 12V at the radio memory wire? These four circuits are fed by the same bus on the fuse panel, and all four should be hot at all times (HAAT), meaning they should work no matter what position your key is in.
May I ask you to post a picture of the back side of your fuse panel? The side with all the wires; we'll compare it to the picture on Page 22 (Rev W from 2019) of your RF installation instructions.
Check your fuses, too. As obvious as it seems, you'd be surprised how many of us spen hours chasing electrical issues that end up being a simple blown fuse. It's easy to pop a fuse with all the loose wires hanging out during the build process.
Yes I actually went through all fuses thinking same thing. Soooo I attempted to get that fan to run by pulling the Thermo wire and grounding it and that was unsuccessful - nothing doing. I also have been weary of the fact that the horn doesn’t work. I back burnered it because….its a horn….but it had been haunting me thinking it was a sign of other issues. Attached is the pic of the back of the panel. Pretty standard for how it came out of box. But let me know what you see. Thanks again guys really appreciate your time on this.
Looking back at your first picture, I see a Holly hand-held, so you are using EFI (Sniper probably). I recommend letting the EFI control your fan rather than relying on that old-school thermo switch. The Sniper has a fan control wire (light blue) in the ten-pin connector that you just connect to the ground trigger on the fan relay (the same green wire you are using at the switch). The Sniper should have come with a coolant temp sensor, just like the one your temp gauge uses. You can use the hand-held to lower the fan#1 trigger temp to turn the fan on at room temp.
The fan and horn are both on the Battery feed, along with your hazard lights and headlights. If none of those are working, my guess is that you have the ignition switch wired incorrectly.
Well, no obvious mis-wiring at the back of the fuse panel. So as Papa says, the next step is to check if you have headlights, hazards, and 12V at the radio memory wire. Turn on your headlights & see if they come on, and turn on your hazards to see if they blink.
If you don't have your lights wired yet, the easiest of these to check will be the radio memory. Set your multimeter to measure DC volts; then use a jumper to connect the red radio memory wire to the red lead of your multimeter, and then touch the black lead of your multimeter to any ground that's convenient. You should measure ~12+ volts, depending on your battery. You'd use the same process to check the headlights & hazards on the corresponding wires.
If all four circuits don't have power, follow Papa's lead & double check the wiring on your ignition switch.
Thanks guys this provided me a collective path forward for diagnostics. I am going to try these things tonight and tomorrow and I’ll report back.
I do like the idea of having the sniper control the fan a lot. I may just wire that up and see if that gets me there. Dumb question though - does the sniper need a separate connection to the temp probe or is that built into it? My understanding is that I basically just need to swap the thermo sw green wire with the light blue wire off the sniper 10 pin connector on the existing relay, and that the temp controller itself is built into sniper. But we all knows what happens when I assume ��
Thanks guys this provided me a collective path forward for diagnostics. I am going to try these things tonight and tomorrow and I’ll report back.
I do like the idea of having the sniper control the fan a lot. I may just wire that up and see if that gets me there. Dumb question though - does the sniper need a separate connection to the temp probe or is that built into it? My understanding is that I basically just need to swap the thermo sw green wire with the light blue wire off the sniper 10 pin connector on the existing relay, and that the temp controller itself is built into sniper. But we all knows what happens when I assume ��
The Sniper uses its own coolant temperature sensor (TCS) that is the same as the TCS that feeds your temp gauge.
If Mike installed it for you and you used it for your gauge, go back and find the one that should have come with your gauge and install that one, too. Don't connect the gauge and the Sniper to the same sensor. Do you get a water temp showing in the Sniper handheld? This is important as the Sniper uses coolant temperature to adjust fuel enrichment as well as controlling the fan.
Dave is spot on with his advice. I will add that all your temperature sensors need to be in good coolant flow and be well grounded to the block. Your pictures make it look like this might not be the case. Unless it is specifically designed for this purpose, the sealant around your sensors and fittings has to go. The sensor in the T in the intake manifold may not be into the coolant flow enough and, if the other line on the T is for a heater, won’t read correctly unless the heater is on or you have a bypass heater control.
Look on the driver side front of your intake. Most have another port for a temperature sensor. The one in the water neck is not suitable for a gauge or Sniper sensor. There will be no temp increase sensed until the thermostat opens.
Circled in red on the attached picture is the Sniper ECT sensor in the driver side port on my manifold. The sealant on it was there when shipped from Holley so I assumed it was conductive and suitable.
HTH
Norm
Mk4 base kit 7721, 331 Stroker, Holley Sniper EFI, Wipers, Heater, Whitby Soft Top, Drop trunk mod and more
Yup I officially feel like a dope now. I couldn’t work thinking about this so I went to the garage and checked. Sure enough Mike installed the Sniper temp sensor on driver side exactly like Norm shows in his pic so looks like I’m good there. I attached a pic.
So my plan for tomorrow is to wire up the sniper control to fan. Test it to make sure works. If all is good I’m removing that ridiculous T that I have the water temp probe and heater lines hooked up to. Installing the water temp gauge where the old manual thermo switch is so my dash gauge still works and then hopefully problem is solved!
Thanks again guys - this was excellent support. Yet another thing that boggled me but now as you walked me Through seems so logical. Ugh but this is why I have love building this car! IMG_5909.jpg
You guys aren’t going to believe this. I spent 6 hours between yesterday and today working this fan issue. Your guidance was all spot on and I went to work. First I wired the sniper light blue wire to the green Thermo switch wire. Adjusted on /off temp on handheld for the fan and relay clicked but no fan on. I followed the wiring with volt meter and had power all the way to the fan. Same with the horn! Clearly frustrated at this point I assumed the fan motor was defective. So I came in the house for a coffee and thought about it. I realized I hadn’t checked the grounding so I ran back out and manually grounded the fan black wire to the frame. Fan kicked on! So I realized I now had a larger grounding issue (Dave you were right on that something larger was at play here with the power system). So I went to work tracing every ground wire. Took the whole dang thing apart and regrounded everything. Still no luck. I mean I love problem solving but this almost did me in haha. You’re not going to believe it but the harness connector plug for the front harness was wired wrong!!!!! The black and gray wires were flipped! I couldn’t believe it and never expected this to be an issue that came from the factory. Check out the pic. I’m blown away. So I manually wired this wire set and voila - fan works. Horn works. Unbelievable. Thanks so much again for all the help. Btw I am so happy I have the sniper controlling fan now so may it was all for the best.
Oh by the way - my voltage meter was missing a ground wire. That one’s on me. So that’s fixed now too. I just have to figure out the speedometer issue. There are two sets of Speedo green and gray wires - maybe I have wrong set connected?
You guys aren’t going to believe this. I spent 6 hours between yesterday and today working this fan issue. Your guidance was all spot on and I went to work. First I wired the sniper light blue wire to the green Thermo switch wire. Adjusted on /off temp on handheld for the fan and relay clicked but no fan on. I followed the wiring with volt meter and had power all the way to the fan. Same with the horn! Clearly frustrated at this point I assumed the fan motor was defective. So I came in the house for a coffee and thought about it. I realized I hadn’t checked the grounding so I ran back out and manually grounded the fan black wire to the frame. Fan kicked on! So I realized I now had a larger grounding issue (Dave you were right on that something larger was at play here with the power system). So I went to work tracing every ground wire. Took the whole dang thing apart and regrounded everything. Still no luck. I mean I love problem solving but this almost did me in haha. You’re not going to believe it but the harness connector plug for the front harness was wired wrong!!!!! The black and gray wires were flipped! I couldn’t believe it and never expected this to be an issue that came from the factory. Check out the pic. I’m blown away. So I manually wired this wire set and voila - fan works. Horn works. Unbelievable. Thanks so much again for all the help. Btw I am so happy I have the sniper controlling fan now so may it was all for the best.
Oh by the way - my voltage meter was missing a ground wire. That one’s on me. So that’s fixed now too. I just have to figure out the speedometer issue. There are two sets of Speedo green and gray wires - maybe I have wrong set connected?
Congrats on working it to root cause and correcting the harness issue. I'd like to say you are the first to see something like this, but there have been quite a few stories posted on the forum of similar issues with the Ron Francis harnesses and what engineers call a quality escape. At least in this case, the emergency exit didn't blow off at 25,000 feet.
Mike, congratulations on tracking down the issue. Unfortunately I too have seen instances where the “Quality”part of the Quality Control statement seems to be missing.
Dave, your comment about emergency exit doors would be a little more humorous if I didn’t fly 737s for a living. Thankfully we don’t have 900s in our fleet. I am going to steal one of my daughters sayings and say that some people need to “get their poop in a group”
Norm
Mk4 base kit 7721, 331 Stroker, Holley Sniper EFI, Wipers, Heater, Whitby Soft Top, Drop trunk mod and more
Mike, congratulations on tracking down the issue. Unfortunately I too have seen instances where the “Quality”part of the Quality Control statement seems to be missing.
Dave, your comment about emergency exit doors would be a little more humorous if I didn’t fly 737s for a living. Thankfully we don’t have 900s in our fleet. I am going to steal one of my daughters sayings and say that some people need to “get their poop in a group”
Norm
Norm,
Stay safe! My comment wasn't meant as an insult, but as an observation on where the engineering profession is headed when quality is sacrificed for the sake of profit. I'm asked on nearly every project I work if all the testing is really necessary or where we can reduce the test program, which is often the most costly aspect of a project. As much as I think Boeing should be held accountable, it is often the customers that are asking to reduce costs by trimming testing costs.
Dave, believe me it wasn’t taken as an insult. A lot of companies have been reducing costs to the point that it is actually costing them money. Boeing might be one of the best examples currently but, they are not alone. Lots of places need to get their “stuff” together.
Norm
Mk4 base kit 7721, 331 Stroker, Holley Sniper EFI, Wipers, Heater, Whitby Soft Top, Drop trunk mod and more
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Originally Posted by zanman
