New St1100 owner...probably some old questions

[Nczcar01]

Purchased a 93 ST1100 last month so my old GL500 can have a stablemate. I have been pouring over many posts about the various electrical and mechanical issues that may arise as these great bikes age. My ST still has the original 28A alternator and understand it will most likely be a matter of time until I will need the 40A upgrade. Until then, I have been checking the weak points in the wiring and conducting various PM procedures. I removed the red 3P connector and hardwired the three yellow wires (some deformation of the plastic connector observed). Also noted heat discoloration on the the red wire insulation in the 4P connector that plugs into the starter switch, so I cleaned all the terminals, stripped the red wire to clean copper and installed a new female crimp solder connector.
No damage noted on the VR modular plug, but did clean the terminals and applied dielectric grease to this and other connections. Plan to install a voltage meter as well. While being around cars most of my life (old drag racer) I never really noticed how hot some of the wires and connectors normally operate. Has anyone taken temp readings of these weak connector points on the ST1100? I assume most of the wiring insulation on this bike is rated as 105C (just a guess as it appears to be similar to AWM electrical wiring), so to char or melt various insulation materials, poor/resistive connections must push the temp pretty high.
I am getting 14.6V at the battery at high idle with high beams, so this seems in line with what I read as in the normal range, but curious if anyone would know what temp ranges would be considered above "normal" at these weak wiring connection points.

 

[kiltman]

I can't comment on the temp readings, but from what you outlined above, you've addressed a lot of things that could cause grief down the road. Depending what you're planning on running for accessories the 28amp alternator will do OK.
I'm running heated grips and an electric vest, I have a GPS and phone connected as well. ( I have a 1990 ST1100 with a 28 amp alternator)

The red connector by the starter relay was my real trouble spot, until I did what you did and stripped the red wire back till I got clean copper to splice. That relay is a water trap which contributes to the corrosion of the wire. Plying it with dielectric grease is a good solution, as well as checking it after riding some length in heavy rain.
I have a digital voltmeter That I installed to monitor the charging system and it's always indicating that the battery is charging at a good rate.
Good luck with your search on wire temps.
Cheers

 

[Nczcar01]

Thanks for the information and confirmation. Currently not running any additional electrical equipment but will add a phone charger/GPS 12v outlet. After a short ride getting the bike up to operating temperature, I felt the alternator output wiring, various connectors around the battery area, voltage regulator (felt warm), along with starter switch and found most areas were pretty warm. I checked a few areas with my laser thermometer and found wiring ranged from 95-130F. The VR temp ran approximately 140-150F.

 

[kiltman]

There's a redwire bypass that is highly recommended, that takes some strain off of the starter circuit. I haven't done it yet but it's on my bucket list.
You should be OK with those accessories.
Right now I have a hard time justifying the cost of the 40 amp upgrade given the price of a newer post 96 model bikes on the market.
All the best with your st1100, They're great bikes, I've been having lot's of fun with mine. I keep a spare set of connectors in my tool kit ready to splice if I should have problems.

 

[Brant]

Thanks for the information and confirmation. Currently not running any additional electrical equipment but will add a phone charger/GPS 12v outlet. After a short ride getting the bike up to operating temperature, I felt the alternator output wiring, various connectors around the battery area, voltage regulator (felt pretty warm), along with starter switch and found most areas were pretty warm. I checked a few areas with my laser temp gauge and found wiring ranged from 95-130F. The VR temp ran approximately 140-150F.

That heavier mount for the VR works as an actual 'heat-sink'. Removing and cleaning both contact surfaces help with the heat dissapation..

 

[Nczcar01]

That heavier mount for the VR works as an actual 'heat-sink'. Removing and cleaning both contact surfaces help with the heat dissapation..

Thanks Brant. Didn't mention it specifically, but this was one of the PM's I performed earlier. Plan to apply silver thermal paste to the back of the VR tomorrow to help sink and transfer the heat to the aluminum mount.

 

[Nczcar01]

Voltage meter, silver thermal pasted VRR, 12v outlet have been installed. Waiting on a few parts (secondary air filter, fuel filter, Denso iridium plugs, LED lamps) to arrive and install while many of the panels and covers are removed.