Relay upgrades for '79 GS850G

[sarathchandars]

As I carefully extracted the existing wiring harness from my '79 GS850 I found that there are no relays barring the one for the starter motor (not counting the turn signals because it serves a different purpose). I'm planning to include relays for horns (I'm planning to install new hi-low pair), headlight (one relay for on-and off that power the headlight light and tail light on/off, and another for switching high-low beam) and replacing the starter relay solenoid with a more modern one variant.

I traced down to few options (I may change the brand/models but the ratings of the items below should be the same)
1. Horn pair: https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1
2. Headlight hi-low switch: https://www.amazon.com/gp/product/B0...DKIKX0DER&psc=
3. Headlight on/off: https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1 (this will be series with the relay above, so hi-low beam can work in conjunction with the on/off switch)
4. Starter relay: https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1 (the main circuit will get energized when ignition is on, so all lights and accessories can be on, but when the starter button is pressed, it will changeover to the starter circuit cutting off all lights; I'm looking for a 40A version and will use it if I get it)

Does anyone with experience modernizing the electrical of these bikes have any comment/advice on these?

Separately, I'm looking for avenues to overhaul the turn signal system as well. I found the note on bikecliff's website and found one for replacing the turn signal relay. But there is an aging control unit that I don't mind replacing if there are options to make it more modern. Any suggestions?

Thanks in advance!

[Nessism]

"Comment/advice on these"

Your bike will run to 100,000 miles in stock form with just standard maintenance. Adding relays is the answer to a problem that doesn't exist.

My opinion, before you go adding splices and cuts into your harness to add these relays, clean all the connectors, and refresh the harness in general. That will pay off in clean running, and make most of the mods you propose, unnecessary.

[sarathchandars]

Hi Ed. I value your advice! The unfortunate thing is that the turn signal is shot (I checked that all bulbs are fine) and the horns are missing, more worryingly there are no wires for the horns! Lastly the upgrade done by the previous owner for Dyna ignition has so many splices and just electrical tapes without connectors. Lastly, to examine the harness as per stock specifications, I took it out as carefully as I could, and found that few connectors are breaking off exposing the terminals. So it looks like I’m in for some reasonably extensive work so I thought I’d factor in some upgrades. I may not get to everything both because I may not have time or money or both, but preparing an inventory of everything.

this is before I get to the engine that smokes and smell like It’s burning oil.

[Burque73]

Hi Ed. I value your advice! The unfortunate thing is that the turn signal is shot (I checked that all bulbs are fine) and the horns are missing, more worryingly there are no wires for the horns! Lastly the upgrade done by the previous owner for Dyna ignition has so many splices and just electrical tapes without connectors. Lastly, to examine the harness as per stock specifications, I took it out as carefully as I could, and found that few connectors are breaking off exposing the terminals. So it looks like I’m in for some reasonably extensive work so I thought I’d factor in some upgrades. I may not get to everything both because I may not have time or money or both, but preparing an inventory of everything.

this is before I get to the engine that smokes and smell like It’s burning oil.

That sounds like a real mess. Would you like an unmolested harness? I have one from a '79 850. You may still wind up replacing some brittle or broken connectors, but at least the wire is all there.

[sarathchandars]

Hi Roger, very kind of you to offer. I'll still need to modify it "slightly" to support the Dyna ignition system. Does your harness have a turn signal system? If not, I will still have to (sort of) dig into the harness to make it work. The ideas that I had initially shared are actually relatively simple to implement with a modern blade fuse box. But the urgency depends on getting the turn signal system up and running... I haven't yet brought my multimeter out and stored the harness in a box. But once I get through the carbs and seal the airbox I'll get to the harness. Winter is coming

[Burque73]

No, I'm afraid the turn signal system is gone. I just have the main loom.

https://flic.kr/p/2qwtSzW

[salty_monk]

I ran basically the whole bike through a relay at one point... It's a bit of messing around but not hard to do & takes out most of the usual weak spots in an old loom.

[oldGSfan]

I gained 1.5V putting a coil relay in (but added a failure point). I may have accomplished the same by going through the whole path like Ed says (and he's probably right). But it works and the bike fires on the button better than any I've ever had.

Relay yeah!