Russ Thompson Turn Signal setup

[Phoenixmsb]

Hello all!

In the middle of my Roadster build and am up to the electrical. I've had no problems to date (well, just some small ones) but I'm up to the point of installing my Russ Thompson turn signal setup. I've had no worries tackling my wiring but I'm worried getting into this. I'm just doing the turn signals and using the button on the stalk for the horn. My question?

Has anyone come up with a small wiring harness that I can kind of Plug-and-Play for this? I'm not sure with getting into relays and that sort that isn't factory packaged - I'm just looking for an easier way I guess.

Thanks for any input on this.

Bruce
Phoenixmsb

[edwardb]

What you're describing is very simple if you have the Ron Francis harness. Doesn't require any relays or anything exotic. The five wires coming out of the Russ Thompson turn signal just need to be positively identified and wired to the Ron Francis harness exactly as shown in the schematic. Russ provides instructions explaining which wire is which. But a good idea to confirm with an ohmmeter or continuity checker.

Two wires from the momentary switch (button on the stalk) to the two horn wires in the harness. Doesn't matter which is which. The relay for the horn is in the Ron Francis fuse panel. The momentary switch closes it and honks the horn.

Three remaining wires -- one common, one right, one left -- go to the wires shown in the schematic as the turn signal switch. When the turn signal has the right turn actuated, voltage is applied through the common lead to the right turn lights. When the turn signal has the left turn actuated, voltage is applied through the common lead to the left turn lights.

I'm assuming with my answer you have the hazards and indicator lights wired exactly as shown in the Ron Francis schematic. That means separate indicators and the double pole switch on the hazards. If either of those are not wired exactly as shown, the above may not work correctly due to backfeeding.

Also assuming you're using the kit provided headlight switch and low/high beam switch. The relay(s) typically associated with the Russ Thompson turn signal are related to the low/high headlight function. Relay(s) aren't needed if you use the kit provided switches and wiring.

[Phoenixmsb]

Thank you for this help. I'll keep your notes as I DO have the RF harness.

Thanks!
Bruce

[32J]

Hi - I'm starting on the harnesses and the Russ Thompson turn signal system. I have the MKIV Roadster with the Ron Francis harness, and Rev W of the installation booklet (Nov 2019). The wiring schematic for the dash harness and the turn signals, etc. is shown as Rev T.

The paper instructions that Russ provided with the signal system mention a VW relay, a Bosh Relay, and some diodes. This looks to be for someone who is is building a harness from scratch. Do I still need these? I'm presuming that I can just join the wires from Russ's system into the dash harness.

Thanks,

32J

[edwardb]

Hi - I'm starting on the harnesses and the Russ Thompson turn signal system. I have the MKIV Roadster with the Ron Francis harness, and Rev W of the installation booklet (Nov 2019). The wiring schematic for the dash harness and the turn signals, etc. is shown as Rev T.

The paper instructions that Russ provided with the signal system mention a VW relay, a Bosh Relay, and some diodes. This looks to be for someone who is is building a harness from scratch. Do I still need these? I'm presuming that I can just join the wires from Russ's system into the dash harness.

Thanks,

32J

The wiring diagrams included with the harness are to provide a switching method for low/high headlights using the RT momentary switch. Something that a lot of builders want. Not to get off track, but there are other ways that are perhaps a little easier and better. But to your question, no you don't need to build those circuits to use the RT switch for a basic turn signal function. The three wires from the switch wire to the Ron Francis harness exactly the same as the kit provided dash switch. The other two wires are for the momentary switch. Some use that for the horn. Which can also be done without modification and again only replacing the kit provided dash pushbutton switch.

[32J]

Thank you, Sir!