I am working on my dash. MK4 complete kit delivered Nov 2019. Gauges are installed in dash. But having issues with the wiring. Every post and picture I see shows the Vintage gauges with 3 sets of wires. One (red/white/black) daisy chain for needle, power and ground, one (black) daisy chain for the backlight/dimmer ground, and one for the sender connections.
All of my gauges only have the red/white/black daisy chain and senders. No black wires. Even my instructions only show one. What am I missing? Will the needles and dials be illuminated? Will the light switch dimmer adjust both the needle and face? See attached pictures.
Sorry for the simple question, but can't figure it out. Thanks as always
What you're dealing with there is Speedhut made a change to the gauges over the past year or two (not positive when, but fairly recently) and the instructions you have don't reflect that. Speedhut gauges used to have separate circuits for the backlighting and needles. The old backlighting ran on AC (hence the inverter) and could only be dimmed with the Speedhut provided trimmer. Needles were LED. So there were two lighting wires coming out of the gauges.
Now the gauges are 100% LED (including the backlighting) so only have one lighting wire. The white one. It powers both needles and backlighting. Not sure what they're doing with the dimmer function. The kit supplied headlight switch has a twist for gauge dimming. It varies the voltage. I doubt it will actually dim. Probably just go from full on to full off when the voltage drops below the LED's forward voltage. But not positive. Maybe someone else knows that part.
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I am wiring my dash as well and noticed the very same thing missing the black separate wire as well. I assumed it was a change that did not reflect in the RF harness instructions. Thank you edwardb for the verification.
FFR MK4 Roadster (9945) complete kit, delivered 12/4/2020, First start and go kart 5/7/2021. Legal 8/14/2021, Paint finished 7/18/2022 (Viking Blue). 347BPE CI, TKO600, Moser 8.8 3link 3.55, Halibrand 17x9 17x10.5, power steering. Carbon Fiber Dash. Carbon Fiber trans tunnel, adjustable Kirkey Lowback Vintage seats, Vintage gauges, RT drop trunk mod, FFmetal drop battery mod and trans tunnel, Forte front sway bar. Forte mechanical throttle linkage, RT gas pedal. www.covespringsfarm.com
Thanks edwardb. Knew there was something new, but could find no one else with this. Even on the Speedhut website they say all Speedhut gauges require the dimmer. Maybe I'll give them a call tomorrow. Appreciate your fast response as always.
vtullomk4 if you speak with them I would be interested to hear their response. BTW, Love your 944 with cookie cutter wheels.
FFR MK4 Roadster (9945) complete kit, delivered 12/4/2020, First start and go kart 5/7/2021. Legal 8/14/2021, Paint finished 7/18/2022 (Viking Blue). 347BPE CI, TKO600, Moser 8.8 3link 3.55, Halibrand 17x9 17x10.5, power steering. Carbon Fiber Dash. Carbon Fiber trans tunnel, adjustable Kirkey Lowback Vintage seats, Vintage gauges, RT drop trunk mod, FFmetal drop battery mod and trans tunnel, Forte front sway bar. Forte mechanical throttle linkage, RT gas pedal. www.covespringsfarm.com
You will also run into problems hooking up your oil pressure and temperature gauge. Same issue with there not being up to date instructions from FFR. I ended up calling Speedhut and they were able to help me figure it out. JB Nova also has some really good info in his build thread that I was also able to use, definitely recommend taking a look at it.
I still cant get my dash lights to properly dim, they are either on or off. I do not think I would ever need them to dim so I am just going to leave it.
I just went with a Autometer LED dimmer. Have used them before, and while a little pricey, they are rock solid. I love as little light as possible from the dash, and this provides that capability with fine tune control.
You will also run into problems hooking up your oil pressure and temperature gauge. Same issue with there not being up to date instructions from FFR. I ended up calling Speedhut and they were able to help me figure it out. JB Nova also has some really good info in his build thread that I was also able to use, definitely recommend taking a look at it.
I still cant get my dash lights to properly dim, they are either on or off. I do not think I would ever need them to dim so I am just going to leave it.
You must use the LED dimmer. This has been discussed numerous times.
Mrk III, 331 stroker, Borla stack injection, T5, 3:55 IRS, Power steering and brakes. Kleiner body & paint
Just got note back from Dave B at FF. He confirmed that Speedhut has converted to all LED and the headlight switch will not dim the gauges. Just on/off. And to follow the new instructions.
Still a bit confused. Rich, why must I use the dimmer?
Yo DO NOT need a special "LED" rheostat. Use a lower ohm potentiometer (5k-Ohm is plenty), the one that came with my kit was WAY too much resistance. These 10-turn precision potentiometers worked great for me. But there are many others. You don't need more than 3k-Ohms. Just scuff the contacts up before trying to solder them. Some of these also come with pigtails that make connections much easier.
FFR MKIV ordered 12 July 2019. IRS, Wilwood Brakes, 18" Wheels w/MT tires, power steering, EFI, Heat. 347 Dart w/TKO-600 by Mike Forte, Holley FI, MSD coil and CD box. All new, no donor build.
Do you have the FF Chassis Wiring Harness installation instructions? Mine is rev W, Nov 2019 and it matched exactly what my gauges were. There is a revision "T" now: https://www.factoryfive.com/wp-conte...ness-rev-T.pdf
I ran into the same with mine, but if you cross reference the gauge directions with the FFR directions it'll make things easier. Also, the LED is either on or off because the supplied potentiometer has way too much resistance. If you want very fine control, go with a 10-turn 5K or 10K precision potentiometer. The 5K gives twice the fine tuning control (10 turns to 5k-Ohms, vs. 10 turns to 10k Ohms).
Originally Posted by Fman
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I still cant get my dash lights to properly dim, they are either on or off. I do not think I would ever need them to dim so I am just going to leave it.
FFR MKIV ordered 12 July 2019. IRS, Wilwood Brakes, 18" Wheels w/MT tires, power steering, EFI, Heat. 347 Dart w/TKO-600 by Mike Forte, Holley FI, MSD coil and CD box. All new, no donor build.
I talked to Speedhut tech support today. They did confirm that they started to ship all LED gauges to Factory Five about a year ago. And agree that all the documentation has been inconsistent. They think that is now correct on new builds. They have not launchd the all LED gauges on their web site, just to FF. Still only offer the combo units with the inverter dimmer as standard. LED's coming down the road.
So he confirmed there are a few options:
Use the all LED ones and understand the FF headlight dimmer will be on/off only. No dimming.
Add resisters to the LED circuit if they appear to be too bright.
Purchase a set of gauges with the dimmers and sell the FF LED gauges.
He said the all LED's will have longer life and maybe a bit brighter. Thanks why some people put in resisters.
Have not decided what I will do. I may mock up my dash with a battery and see how it looks day and night. Another option is to buy a colored face (red, as my car is red) which they say has higher visibility and contrast.
I talked to Speedhut tech support today. They did confirm that they started to ship all LED gauges to Factory Five about a year ago. And agree that all the documentation has been inconsistent. They think that is now correct on new builds. They have not launchd the all LED gauges on their web site, just to FF. Still only offer the combo units with the inverter dimmer as standard. LED's coming down the road.
So he confirmed there are a few options:
Use the all LED ones and understand the FF headlight dimmer will be on/off only. No dimming.
Add resisters to the LED circuit if they appear to be too bright.
Purchase a set of gauges with the dimmers and sell the FF LED gauges.
He said the all LED's will have longer life and maybe a bit brighter. Thanks why some people put in resisters.
Have not decided what I will do. I may mock up my dash with a battery and see how it looks day and night. Another option is to buy a colored face (red, as my car is red) which they say has higher visibility and contrast.
Vince
Appreciate the update Vince. I think I am just going to have some bright LED gauges and not sweat it too much
FFR MK4 Roadster (9945) complete kit, delivered 12/4/2020, First start and go kart 5/7/2021. Legal 8/14/2021, Paint finished 7/18/2022 (Viking Blue). 347BPE CI, TKO600, Moser 8.8 3link 3.55, Halibrand 17x9 17x10.5, power steering. Carbon Fiber Dash. Carbon Fiber trans tunnel, adjustable Kirkey Lowback Vintage seats, Vintage gauges, RT drop trunk mod, FFmetal drop battery mod and trans tunnel, Forte front sway bar. Forte mechanical throttle linkage, RT gas pedal. www.covespringsfarm.com
Vince, thanks for posting this thread. I'm dealing with the same issue, as F5 wiring instructions (I'm using Chassis Harness Rev W) are not updated to account for the all-LED vintage gauges. If you (or anyone else) wants a soft copy (PDF) of Rev W, send me a PM. My kit shipped with previous version Rev T in Fall of 2020. Toadster was kind enough to send it (Rev W) to me.
I measured the voltage output at the white "Dash Lights" wire on pin 2 of the headlight switch. Using my Fluke multimeter, I measured less than 0.01 volts change between full CCW (just before courtesy light click) and full CW. So, the voltage does not vary, and my gauge lights are full bright. They do not shut off until I turn off the headlights.
I'm going to try this dimmer per a suggestion from Papa. It is also offered with a black knob, and fits in the same size hole as the gauge programming button--important for me as I already purchased (later returned) the Speedhut dimmer kit, and drilled the 0.265" hole in my dash. Engineered and manufactured in the USA--Bonus!!
Quick update: I installed the LED dimmer switch today and it works! It has On/Off functionality as well as LED dimming. There is plenty of fine dimming adjustment.
One interesting note: with the knob full CW (full bright) the gauge lights shimmer. Rotate the knob just a tad CCW and the shimmering stops. Since I now have full dimming adjustability, I'm calling it good.
Thanks again to the forum for the advice, and a special Thank You to Papa who sent me the link to the LED dimmer switch.
LED dimmer switch
Chris Coupe complete kit delivered: 4/22/24. Build Thread. Coyote. T-56. IRS w/3.55. Wilwoods. PS. HVAC. Side windows. MK4 Complete kit. Build Thread Index. Delivered: 10/15/2020. Legal: 7/25/23. Coyote Gen3. TKO600 (0.64 OD). IRS w/3.55. PS. Wilwoods. Sway bars. This build is dedicated to my son, Benjamin. Build Thread.
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Originally Posted by Fman
