Red Wire Bypass ( + Red/White wire )

Joined
Sep 13, 2011
Messages
30
Location
Norway
Hi.

I want to show you my version of the Red Wire Bypass.
My english is not 100%, but i will give it a try....

I started to do the red wire bypass. But when i study the electric scheme for my ST1100A '93 i figured out i had to do a little more then the red wire bypass threads are saying.

People do the bypass for reducing the heat / current through the connector to the starter relay.
Original there is one large current passing first in , and then out of the connector. (Main current). The current came from the regulator/rectifier, goes into the connector and then out again from the connector to all the supplies to the electrical system.

One major fault in the OEM- setup. (My opinion), is that this large current is NOT passing through the 30A main fuse.
When the bike is charging, the current flow from the regulator and out to the supplies to the electrical system. -Not passing the main fuse.
The only very little current flowing through the 30A main fuse, is for charging the battery and for the ABS-fuses.

When you do the ?normal? Red Wire Bypass, the main current from the regulator still flow through the connector. Passing the 30A main fuse on the connector, and then to the battery. -Then through the fused Red Wire Bypass and out to the supplies.

You still have the main current flowing through the connector to the starter relay.

My opinion / solution is to do a Wire Bypass also for the Red/White wire from the regulator.
The current through the connector is then removed completely.

I have now Bypassed the Red wire with a seperate fuse.
I have bypassed the Red/White wire with a seperate fuse.
I have also removed the connector for the Red wire from the battery, feeding the fuses for pump motors and the solenoids for the ABS. (Removed connector, and connected direct to battery).

Kairo


IMG_2446 (Small).JPGwiring diagram st1100 92-95 abs 2.jpg
 

CYYJ

Michael
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Kairo:

Thank you very much for writing the description of your modification.

I have a 2001 ST 1100 - is this modification appropriate for all years of the ST 1100, or only for older models, such as your 1993 bike?

Michael
 

John OoSTerhuis

Life Is Good!
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Bettendorf, Iowa
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1991 SSMST1100
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1058
Yes, connecting the red/white wire from the VRR directly to the battery +post is an acceptable modification for the older ST1100s with the oil-cooled 28amp systems.

For those doing the 40amp upgrade, the old main 30A fuse (or smaller) can be left in and the red/white lead used as a fused, unswitched (always hot) circuit for an electrical farkle of your choice. BTDT Also for a 28amper with a red wire bypass if there's enough lead left to splice into.

Regards, John
via iPhone 4S
 
Last edited:

John OoSTerhuis

Life Is Good!
Joined
May 10, 2005
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5,219
Location
Bettendorf, Iowa
Bike
1991 SSMST1100
STOC #
1058
PS I just advised another STrider about this possible mod. He'd done the red-wire bypass. Bike ran fine for awhile. Then his battery wasn't being charged. Long story short, the old main fuse had blown and the red/white wire had no connection to the battery. Unfortunately, by then he'd replaced the battery, VRR, and had the bike apart to install a replacement stator. :(
 

CYYJ

Michael
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Toronto & Zürich
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Yes, connecting the red/white wire from the VRR directly to the battery +post is an acceptable modification for the older ST1100s with the oil-cooled 28amp systems.
Thanks for the quick reply John.

Just to confirm, and to remove any possible doubt: This modification is NOT needed on the later production ST 1100s with the 40 amp alternator, correct?

Michael
 

John OoSTerhuis

Life Is Good!
Joined
May 10, 2005
Messages
5,219
Location
Bettendorf, Iowa
Bike
1991 SSMST1100
STOC #
1058
Thanks for the quick reply John.

Just to confirm, and to remove any possible doubt: This modification is NOT needed on the later production ST 1100s with the 40 amp alternator, correct?

Michael
Couldn't do it even if you wanted to - there is no red/white wire on ST1100s with OEM 40ampers. Look at their wiring diagram. :)

John
 
OP
OP
Joined
Sep 13, 2011
Messages
30
Location
Norway
Thanks for the quick reply John.

Just to confirm, and to remove any possible doubt: This modification is NOT needed on the later production ST 1100s with the 40 amp alternator, correct?

Michael
The wire from the VRR on the 40A alternator is not going through the connector for the starter relay.
You still have your red wire, feeding all your supplies (Main current). This wire is going through the connector for the starter relay.
This connector have been a weak link on the earlier models
You can still do the "Normal" Red Wire Bypass on your later production ST1100 with the 40amp alternator, and eliminate the possibiliti for a heated / melted plug.

Kairo
 
Joined
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Messages
2,211
Location
West Michigan
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'98 ST1100
STOC #
8470
BTW, When I did the red wire bypass on my '98 I also added a 45 amp relay, close to the fuse panel, to eliminate the load current through the ignition switch. This also eliminated the "IR" drop of the load current in the wire up to and then back from the ignition switch.
I also added a horn relay to eliminate the high current through the horn switch.
 
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