Hitchcocks Forum

I've posted a few times before about my lighting problem, well whilst investigating i have found that someone has disconnected the original reg/rect units and fitted a power box at some point. I assumed i could just disconnect the power box and reconnect in the new reg/rect units from hitchcocks...... well i did this and it blew the 20a fuse in the lh side panel. even with the ignition off??

now for starters i cant see this 20a fuse on the wiring diagram, but it appears to have a red wire connected direct to the battery and then has a black wire which goes into the harness and disappears off up to the headlight.

so, is this 20a fuse something to do with the power box? why would the reg/rect unit cause the 20a fuse to blow?

the engine runs with the power box connected but not the reg/rec unit.

please help, i've got the MOT on Friday and was planning on going on a long ride on Sunday!!

Cheers
Ian

Hi IAN D---------- If it runs ok with the power box in-circuit then leave any investigations until after you return from a really fun-packed Sunday ride !! Besides, why would you want to reinstate those god-awful reg/rect. units anyway ??

Hi Alan R, It runs ok, but the headlights don't work and i need them working to get through the mot on Friday before the big ride on sunday.

oh and i hadnt realised the powerbox was there until i took the seat off, and i had assumed the reg/rec unti was knackered hence buying a replacement before i got stuck in.

The reg/rec should be a reasonably straight forward fit. The three wires the come out of the alternator that aren't earth need to be paired into a combination of 2 and 1 that provided the highest voltage output (multimeter required). These then are your AC wires that connect to the two wires that are the same colour ( yellow in my case) coming out of the reg/rec. ( I'm assuming that you've got a single phase reg/rec ) then the other two wires will be + and - usually black and red. Assuming your bike is negative earth ( no by any means a certainty) the negative goes to a suitable earth and the positive can go to the input side of the ammeter or straight to the battery. To see what polarity you bike is look at which terminal of the battery has wires going to the frame. A lot of the early type are positive earth so this is an important check. Good luck

Hi Simon, thanks for the reply, my bike is a 2008 sixty-5 model so it has the plastic plugs. Getting the reg/rec plugged in is the easy bit, its the fact that as soon as i plug it in the 20a fuse blows, without the ignition even being on.

That sounds like a short to me. Either you are connecting it up wrong or there is a short where there shouldn't be. I suggest if the lights aren't working its possibly a related matter and the Power Box might not be the problem. Firstly I would isolate which wire is shorting to and establish via a wiring diagram what it's purpose is, light ignition etc and then I suggest that you pull out the headlight or switch block and start looking for a short. It could be a wire that has been scraped bare or a connection that's come loose. Good luck.

Perhaps I have this wrong but I thought the headlight on the 65 was AC fed direct from the alternator through an AC regulator to the light and thus only works with the engine running. If so I can't quite understand why the powerebox/reg rectifier unit is suspect. If the headlight isn't working with the engine running then surely it must be either the alternator coil, AC regulator or wiring thats at fault. It's a different circuit to the power box. If I'm right, so long as the power box is delivering charge to the battery, then I would leave it in place. Re fitting the reg/ rectifier unit seems a retrograde step and not one that will cure the lighting issue.

Thanks Frank, I have argued this fact in a previous thread so much I give up and will not bother posting on it again because people just dont listen

Hi guys--------- FRANK, NORM ---- add my name to that as well... I had a Bullet 65 a few years back and seem to remember problems with the headlight bulb holder shorting out ??-------- IAN D, from that last description you have a direct short that's independent from the ignition switch... My guess is either one (or a pair) of wires chafing together OR onto the frame somewhere.....Anyone remember how to use a Wheatstone Bridge to calculate the distance to a fault ?? No ?? Me neither, alas.