Long time rider and MSF coach, but I'm new to ST100 think I may need to replace the rectifier/regulator on my 1995 ST1100. Any help would be appreciated.
Rectifier / Regulator location
- Thread starter JHale
- Start date
It’s located on the left side near the battery. You will need to remove the left pannier then the left panel to gain access to it. There will be a white multi pin code connector to it. Remove it and inspect it for melting and or burn’t connectors. To the left of it is the main relay, there should be a green 30amp spare fuse in a holder. There’s a black rubber boot over a red connector, remove the connector and inspect it for melting and or burn’t sections. Above it you should see three yellow wires coming from behind the frame, those three yellow wires will be going to the Voltage regulator/rectifier. There’s a red connector in the middle of those three wires, inspect it.
Lastly put a sheet of white paper under the alternator ( it’s at the back of the engine in front of the swing arm. Leave that paper under it overnight. Let us know if you have evidence of oil on the paper. Also let us know the condition of each of the above mentioned connectors and we can take it from there on what might be issues and further tests you need to do. I’m guessing you’re having a charging issue.
Lastly put a sheet of white paper under the alternator ( it’s at the back of the engine in front of the swing arm. Leave that paper under it overnight. Let us know if you have evidence of oil on the paper. Also let us know the condition of each of the above mentioned connectors and we can take it from there on what might be issues and further tests you need to do. I’m guessing you’re having a charging issue.
How many miles on the bike and what voltage are you seeing at the battery while running at @ 3,000 RPM.
Do all the checks mentioned by Kiltman. Do you have the Honda Service Manual, or the Clymer Manual? Some alternator testing will be required if you don't find a wiring issue first.
Do all the checks mentioned by Kiltman. Do you have the Honda Service Manual, or the Clymer Manual? Some alternator testing will be required if you don't find a wiring issue first.
CYYJ
Michael
Hello @JHALE :
Welcome to our forum community. @kiltman has given you good advice, abov.
While you are in there, very carefully inspect the condition of the connector with th 30 amp fuse that is just to the left of the main fuse. It is a known point of failure. There is a modification you can embody called the Red Wire Bypass that just about all of us who ride ST 1100s have carried out. This modification is highly recommended because when the OEM wiring fails, it leaves you stuck at the side of the road with no power of any kind, well and truly screwed.
There is a more elaborate modification you can make called an Ignition Relay Bypass, but in my opinion, that modification is optional - something you could do over the winter if you want to (I have not bothered). But, the Red Wire Bypass is an essential modification.
Michael
Welcome to our forum community. @kiltman has given you good advice, abov.
While you are in there, very carefully inspect the condition of the connector with th 30 amp fuse that is just to the left of the main fuse. It is a known point of failure. There is a modification you can embody called the Red Wire Bypass that just about all of us who ride ST 1100s have carried out. This modification is highly recommended because when the OEM wiring fails, it leaves you stuck at the side of the road with no power of any kind, well and truly screwed.
There is a more elaborate modification you can make called an Ignition Relay Bypass, but in my opinion, that modification is optional - something you could do over the winter if you want to (I have not bothered). But, the Red Wire Bypass is an essential modification.
Michael
We better ask this too, just in case. Has the bike got the original 28 amp alternator, or has it been upgraded to the 40 amp unit? To tell which you have, look under the engine at the left rear. The 40amp unit is air cooled and looks just like a car alternator, whereas the 28 amp has a smooth round case.