Wiring tips and tricks?

[lahrs37]

I am about to really dive into the wiring process. I have the Russ Thompson turn signal, the Ron Francis chasis harness, as well as front EFI harness for the 5.0 HO and the FFR Vintage gauges.

I have already had the first start, so most of my front harness is set up already. But there are no gauges etc.

I have been searching both forums for a good guide, but have gotten a bit overwhelmed. Does anyone know of any good threads, links, etc. to make this process less daunting? Cheers!

[RickP]

The RT turn signals are a tad tricky to wire in that Russ provides a few schematics to follow. There are a quite a few combinations users have configured and Russ tries to cover them all, hence the multiple schematics. Once I picked out a schematic from Russ that best suited my needs, I employed the help of a friend to interpret them to double check how I interpreted them and from there we dove in. The relays listed can be had at Napa and the diodes I ordered online. When I did my wiring, I ended up just wiring without the distribution blocks depicted but hindsight 20/20, I should of used them as it lends for a cleaner looking circuit.

In the end, the schematics provided by Russ and Ron Francis got me through it and I got it right the first time. A couple of things that threw me for a loop if my memory serves me is if your using the FFR headlight switch, Ron Francis provides a plug for that in the harness. In short, don't over think it like I did. There is a ground "tab" on the side of the switch as well. Also, Your turn signal lamps need to be wired up in order to test the signals etc. It's a complete circuit and things get funky if they are not wired.

I don't have the 5.0 EFI harness or the vintage gauges so I can't comment.


it appears as a daunting task at first but if you take your time, get your soldering correct, crimps tight etc., you will be just fine. Senior guys on this forum can definitely give you advice when needed.


P.S. I don't know if you knew this or not but Ron Francis Wiring (Ron Francis Wire Works) is right around the corner from you and I in Chester. It wouldn't be the first time I called them for advice :-)

[lahrs37]

The RT turn signals are a tad tricky to wire in that Russ provides a few schematics to follow. There are a quite a few combinations users have configured and Russ tries to cover them all, hence the multiple schematics. Once I picked out a schematic from Russ that best suited my needs, I employed the help of a friend to interpret them to double check how I interpreted them and from there we dove in. The relays listed can be had at Napa and the diodes I ordered online. When I did my wiring, I ended up just wiring without the distribution blocks depicted but hindsight 20/20, I should of used them as it lends for a cleaner looking circuit.

In the end, the schematics provided by Russ and Ron Francis got me through it and I got it right the first time. A couple of things that threw me for a loop if my memory serves me is if your using the FFR headlight switch, Ron Francis provides a plug for that in the harness. In short, don't over think it like I did. There is a ground "tab" on the side of the switch as well. Also, Your turn signal lamps need to be wired up in order to test the signals etc. It's a complete circuit and things get funky if they are not wired.

I don't have the 5.0 EFI harness or the vintage gauges so I can't comment.


it appears as a daunting task at first but if you take your time, get your soldering correct, crimps tight etc., you will be just fine. Senior guys on this forum can definitely give you advice when needed.


P.S. I don't know if you knew this or not but Ron Francis Wiring (Ron Francis Wire Works) is right around the corner from you and I in Chester. It wouldn't be the first time I called them for advice :-)

Thanks for the insight! And no, I had no idea they were that close!

[RickP]

The wiring for me has been the most challenging part of the build. Not so much making things work but more about making sense of it all. I can't say good enough things about the RF harness. I pulled the Mustang OEM harness out of my donor and got a big lump in my throat with the thought of the mountain I would have to climb in trying to understand it all. There are some areas in the RF manual that could use some further clarification but for the most part, I was able to find all my answers on this forum or a call to RF.

I'm at that stage in the wiring where I am adding personal touches such as courtesy lights under the dash, power sockets, etc. If you thought your "fist start" was a good feeling, wait until your turn signals, hazard lights, flash to pass, low beam, high beam, not to mention your gauges all working.

[RickP]

just thought I would also mention; and I'm pointing out the idiocy of it all and why the wiring has been challenging for me.....

When I got to wiring the EFI I made this very simple mistake and I felt dumber than a box of rocks after it was all over. I topped the engine off with the proverbial "cherry on top" with an FiTech EFI 600. Not a cheap piece of hardware by any means. After getting it installed and initially wired, I wired up the fuel pump as the EFI has it's own internal fuel pump circuit. Let's just say, first start didn't happen for me. I spent hours trying to figure out why I could read 12v across the fuel pump power wire but could not hear the pump run. When I say hours, I mean several days time. Even went so far as to check continuity back to the EFI unit and deemed something wrong with the EFI itself. After ripping the existing unit out, and installing a brand new one from Summit, I got the same result. Power at the fuel pump wire but no pump running.

After taking a long hard look at the RF schematic, I noticed ground was provided to the fuel pump relay I was tapping into from the Inertia switch. A cold sweat hit my forehead and I thought, "no way". I reached over, hit the orange plunger button to reset the switch, and the car turned right over. Boy did I not feel like dumb a.. of the year.

[Gumball]

I really enjoyed my wiring project and found it very rewarding. Take it slow, make sure you have plenty of grounds, document everything (and keep the records with your build documents), and test it all before you button things up.

I found that having a small lawn tractor battery on the bench or nearby helped to test circuits - just make sure you use a fuse when you do so, in the event that you don't have it wired quite right during the first test.

[boat737]

My advice, take your time. I must have looked at schematics for days, just so I would know exactly where the electrons were supposed to go. I also used the FFR Chassis Wiring Manual schematics. The lables are hard to read, but it's still good.

I do have 2 or 3 schematics for the Russ Thompson turn signal that I have collected over the months, plus what I have written down myself. They are not digital though, just paper copies. I can see if I can somehow get them copied to a .pdf, if I can get the time before being shipped off to training a a few days. I'll try.

[lahrs37]

just thought I would also mention; and I'm pointing out the idiocy of it all and why the wiring has been challenging for me.....

When I got to wiring the EFI I made this very simple mistake and I felt dumber than a box of rocks after it was all over. I topped the engine off with the proverbial "cherry on top" with an FiTech EFI 600. Not a cheap piece of hardware by any means. After getting it installed and initially wired, I wired up the fuel pump as the EFI has it's own internal fuel pump circuit. Let's just say, first start didn't happen for me. I spent hours trying to figure out why I could read 12v across the fuel pump power wire but could not hear the pump run. When I say hours, I mean several days time. Even went so far as to check continuity back to the EFI unit and deemed something wrong with the EFI itself. After ripping the existing unit out, and installing a brand new one from Summit, I got the same result. Power at the fuel pump wire but no pump running.

After taking a long hard look at the RF schematic, I noticed ground was provided to the fuel pump relay I was tapping into from the Inertia switch. A cold sweat hit my forehead and I thought, "no way". I reached over, hit the orange plunger button to reset the switch, and the car turned right over. Boy did I not feel like dumb a.. of the year.

Oh man, I know that feeling!

[lahrs37]

I really enjoyed my wiring project and found it very rewarding. Take it slow, make sure you have plenty of grounds, document everything (and keep the records with your build documents), and test it all before you button things up.

I found that having a small lawn tractor battery on the bench or nearby helped to test circuits - just make sure you use a fuse when you do so, in the event that you don't have it wired quite right during the first test.

That is a cool idea!

[Big Blocker]

FWIW, the Russ Thompson TS switch is a spdt switch that won't take much amperage . . . don't try to use the momentary push button to power a horn or high beam lights - it won't last very long. Use relays and use Russ' switch to activate the relays.

Wiring is basically very simple when you think of it as; power has to come from somewhere (battery), thru appropriate fuses and then connected to whatever switch(s) the power needs to be controlled by (ignition, headlight, horn button, fan, etc.) before traveling to the device being controlled, and then a return path thru the ground of the vehicle. That's the loop . . . power-->fuse-->switch--> device-->ground.

One wire at a time . . . test every circuit before bolting everything up . . . test with a small lantern battery, NOT your car battery. Turn signals and flashers give the most trouble to everyone because they try to test with only one bulb at a time . . . the flasher(s) need to see full amperage draw in order to flash, one bulb won't do it. Be careful how bulbs are installed, it is possible to get them installed 180° out of sync. That will cause shorts to ground or short-circuits to the other close-by circuits. Tail/marker/running (whatever you want to call them) lights are NOT part of the Brake/TS circuit.

Doc

[ThickCobra]

FWIW, the Russ Thompson TS switch is a spdt switch that won't take much amperage . . . don't try to use the momentary push button to power a horn or high beam lights - it won't last very long. Use relays and use Russ' switch to activate the relays.

Wiring is basically very simple when you think of it as; power has to come from somewhere (battery), thru appropriate fuses and then connected to whatever switch(s) the power needs to be controlled by (ignition, headlight, horn button, fan, etc.) before traveling to the device being controlled, and then a return path thru the ground of the vehicle. That's the loop . . . power-->fuse-->switch--> device-->ground.

One wire at a time . . . test every circuit before bolting everything up . . . test with a small lantern battery, NOT your car battery. Turn signals and flashers give the most trouble to everyone because they try to test with only one bulb at a time . . . the flasher(s) need to see full amperage draw in order to flash, one bulb won't do it. Be careful how bulbs are installed, it is possible to get them installed 180° out of sync. That will cause shorts to ground or short-circuits to the other close-by circuits. Tail/marker/running (whatever you want to call them) lights are NOT part of the Brake/TS circuit.

Doc

Doc, you suggested not using the RT stalk momentary switch for the horn as it won't last. I did exactly that and it works fine. Is there a risk that it may fail?

Jay

[edwardb]

Doc, you suggested not using the RT stalk momentary switch for the horn as it won't last. I did exactly that and it works fine. Is there a risk that it may fail?

Jay

He said don't use it directly. Use it to switch a relay. Then the current of the device (horn or whatever) is handled by the relay not the actual switch. If you're using the RF harness, the horn relay is already built into the panel. So using the horn wire through the RT stalk is fine.

[Jeff Kleiner]

Doc, you suggested not using the RT stalk momentary switch for the horn as it won't last. I did exactly that and it works fine. Is there a risk that it may fail?

Jay

Hopefully Doc won't mind if I answer...it won't fail if you use it to activate a relay as he said. If you go directly to the horn it will likely be short lived.

Jeff

[Big Blocker]

Exactly what I was trying to say . . . it won't last very long if you use it directly to activate your horn. The switch contacts aren't rated for what a horn(s) draws.

Always use relays for high current draw items - always.

Jeff, with your F5 experience, you can answer for me anytime . . .

Doc

[GWL]

For those looking for the VW latching relay that Russ recommends in his system I've put together some research that I passed on to Russ a while back.

Original VW number is 111 941 583

Other manufactures part #'s

IMC...................835 54004 001
WD EXPRESS......835 54004 001
BECK/ARNLEY.....203-0002
MEYLE...............100 941 0006
VW...................411 941 583 B
VW...................111 941 583
EMPI.................98-9437-B
Echlin……….........ECH AR284
Standard Motor Products…….SMP LR35

I originally got mine from Air Head Parts at $66 (VW/Audi) with the original part number and it works fine but I just found the following:

The original VW /Audi part at ECS Tuning for $46.85 with free shipping:

https://www.ecstuning.com/Search/111941583/ES289938/

Other brands for less $.

Then I found this site, part cost $26.99 free shipping within US for $49+.

https://www.fcpeuro.com/products/vw-...ay-111941583my

Then I found a better price with the EMPI #, at $20.95 at:

98-9437-B RELAY,HEADLIGHT,12 VOLT,EA

Rock Auto at $25.79
http://www.rockauto.com/en/moreinfo....=39310&jsn=233

ECHLIN at NAPA $33.75
https://www.napaonline.com/p/ECHAR284

Hope this will help those of you that have had problems finding and/or keeping these relays working

George

[ThickCobra]

Doc, you explained it very well, I was just looking for clarification. I particularly liked your power ^ relay ^ switch ^ device ^ ground.

Paul, good to know the relay in within the fuse panel. I wondered what the clicking was each time I connected the battery.

Jeff, thanks for the additional expanation.

Jay

[edwardb]

Paul, good to know the relay in within the fuse panel. I wondered what the clicking was each time I connected the battery. Jay

The horn relay shouldn't click when you connect the battery. Only when the horn wires are connected.

[ThickCobra]

The horn relay shouldn't click when you connect the battery. Only when the horn wires are connected.

Something is clicking each time I connect the temporary battery. Oh boy. Something new to look at.

[edwardb]

Something is clicking each time I connect the temporary battery. Oh boy. Something new to look at.

There are two relays in the battery feed section of the RF fuse block. Horn and cooling fan. But neither should click unless their control wires are grounded. Try holding your finger on top of the case when power is applied. Should be easy to see which one is clicking. Or maybe find out it's something else.

[ThickCobra]

There are two relays in the battery feed section of the RF fuse block. Horn and cooling fan. But neither should click unless their control wires are grounded. Try holding your finger on top of the case when power is applied. Should be easy to see which one is clicking. Or maybe find out it's something else.

lahrs37, I hope I didn't high jack your thread. Hopefully, you're able to use some of this.

It appears to be the cooling fan relay that's clicking. I installed the breeze shroud and his adjustable thermostat, secured to the shroud. I also spliced in a manual toggle switch under the dash to allow me to switch the fan on when necessary. The wiring got a little complicated so I guess I'll spend some time tomorrow tracing wires.

[lahrs37]

lahrs37, I hope I didn't high jack your thread. Hopefully, you're able to use some of this.

It appears to be the cooling fan relay that's clicking. I installed the breeze shroud and his adjustable thermostat, secured to the shroud. I also spliced in a manual toggle switch under the dash to allow me to switch the fan on when necessary. The wiring got a little complicated so I guess I'll spend some time tomorrow tracing wires.

This is exactly the kind of thing I was looking for!