'96 40 Amp Alt/VRR enquiry

[Tackleberry]

I have searched for an answer before posting without success, so I apologise if there is one that I missed.

The last ride I did on the bike covered about 7000km in just over a week. For about half the trip I noticed that the TCS & ABS light were constantly on. My dash lights and tail lights would drop out for extended periods also. The biggest concern was that the volt meter I have installed showed up 15.7v at some points. I also had intermittent starting issues, where there was no kick when pressing starter button, which I believe has been fixed by removing an extra cable form the positive terminal and getting a better connection.

I went through all connections relating to the alt and rectifier as per workshop manual without any error readings.

The bike has around 115 000km on it, and sat for two years before I got it about 18 months ago. When I picked it up it had 93 000km on it, so I have added around 20 000km in the 18 months, and a few extra FARKLEs which I have had somebody calculate the watts and I am within safe limits apparently, with extra to spare for the bike to use if required.

With the readings I am getting I am of the opinion that the VRR is on the way out, but I am open to suggestions from the wealth of knowledge here. Before I start spending big dollars at the dealer any suggestions would be great fully accepted to check.

Thanks in advance to the knowledge trust.

 

[Norm]

Several points which may be useful:

1) Don't bother with calculated Watts as they are so much "guesstimation" as to be useless. The "40 amp" alternator is not a 40 amp unit as the outputs which I have measured vary from 45 to 59.6 amps from the ND "40 amp" alternator.

2) I would expect that you have a connection problem in an area such as the main fuse on top of the starter relay. In many cases it is best just to chop this out of the circuit and to install a new sealed inline ATC fuse holder, IMO.

3) I have written extensively on the 40 amp ND on My-Mc and this group so doing some searches will bring up disassembled photos, directions to "full field" the unit to check to see whether the regulator is the cause of no output, etc.

4) The dealer is not generally the ideal shop to service this alternator as it is an automotive one and, besides that, they will have little or no experience or training in servicing alternators. There will be a small specialty alternator service business in your area who will recognize the alternator as the small frame Nippon Densu used on Suzuki automobiles as well as many other imports, farm equipment and other applications. Common as mothers-in-law! Parts are all common, off the shelf stuff with some variations between models. The only parts which unique to the Honda ST1100 one are the drive-end frame (the front part of the alternator frame which connects to the engine) and the rotor shaft itself which has a unique spline. Even a failed rotor coil or slip rings can be replaced by a specialty shop so, assuming the shaft itself is serviceable, the rotor can be repaired. This last because it may be useful to keep in mind in case.... After several years someone in UK found a local shop who can service the alternators so that issue for them is solved, IMO. You will undoubtedly find a specialty shop there although it may be more difficult than it might appear since these shops often are not known to or deal with the general pubic. If searching, talk with small independent automotive service shops and or heavy equipment/farm equipment shops who may be able to put you into contact.

4) The alternator has only two external circuits, the heavy battery or output wire and the small switched power one. There is a second spade lug connector beside the switched power connector in the alternator rear. This is intended for a no charge indicator light or idiot light but not used on the ST, excepting for some who have added the circuit for various purposes.

5) Check our the main fuse and look to your wiring for any obvious poor connections. Do some wiggle tests by pulling, pushing and twisting the harness where ever accessible.

I can walk you through alternator tests if needed as the manual is a waste of paper, IMO. One limitation may be your ability to measure current or to load the system.

HIH

Norm

 

[Norm]

I just noticed that you have HID's installed. Try disconnecting the HID units and retry as these sometimes have poorly designed modules which can create "noise" in the bike's wiring harness. I have had some issues with problems in electronic modules due to HID on some machines. This is not a high probability but easy to confirm. I like easy.

 

[Tackleberry]

Norm,

I appreciate your feedback thank you. I have a mate that owns his own Mechanical business here in town so he will be able to direct me to the correct electrical shop to check the alternator. Just got back from holidays so it will have to wait until funds are spare again, but I appreciate the direction. I have tried to measure the voltage across the battery when idling and the standard 12.7v appears as it does on the volt meter, so there is something happening when the bike is moving and under load, which as you identified I have had trouble testing appropriately. If you could send me any instructions, or direct me to them, on how to perform some checks I would be grateful because I thought the checks in the book were a little lacking.

As for the HID's this was one area I thought may have been causing problem on the older circuit so they were disconnected during one section of the ride and unfortunately made no discernible difference in the system that I could see.

Thanks again - I will chase up this info and see how I go.

Steve

 

[George]

Nortm is the 'lectronic MAN!