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[scotty]

Hi probs with a 1993 ironbarrel , just off idle volts across battery 12.5 volts fast idlr 1500rpm gets over 13 more revs drops to 11, stop engine and battery volts is 10.75. Alt wires disconected give 20vac between pairs with headlight on fast idle gives bright light but increase gives a dimmer light got me beat dont know if I should get another sparx unit or a lucas one which I think is a wassel who own the lucas name oh for the good old days when the company name on the box was the mob that made the part inside.

[Scalyback]

It could be the regulator, or rectifier/regulator (has 4 wires to it.



Sometimes if they are old, they can start to break down and leak power as the voltage increases. Usual sign is if it is getting pretty hot (very to bloody hot range).



This does not sound like an overheating issue as they tend to start out well and slowly break down as the journey progresses, but do check that some previous muppet has not hidden the thing away in one of the toolboxes which is what happened to Tornado!



Ideally, it should be under the seat, or in a position where the passing air will cool it, especially when the headlamp is on.

Otherwise, I am not sure, but will have a think. Anyone else?

[PeteF]

At 1993 I'd be looking at the reg/rec too, they weren't brilliant when new so if it's the original it could be on the way home.
I'd also be interested at the voltage off your alternator before the regulator. This should be a 3 wire alternator at that date so everything is powered by the battery.
If you do have to replace the reg/rec don't enclose it (as Scaly says) I even fitted a heat sink plate to the back.
Just a thought before you do anything else - check the earth wire!

[Lennie]

Mine did exactly the same, the faster I went the dimmer the lights became, I exchanged the single Regulator/rectifier unit for the two part Regulator and Rectifier. Problem solved.

[scotty]

Hi looks like I, ve found the prob, battery chargeing all over the place think maybe a plate loose in batt. Put a alarm batt in place and get 13.8 at half throttle and holds steady ordered new lucas set from uk and motobatt battery local.unit im replaceing was sparx first one lasted 10 years this one about1 and the plastic around the coils starting to crack not as well made as the first one thanks for all your help will post when I get new bits.

[PeteF]

13.8 seems reasonable - ideal is 14.2

[Blown265]

Evening gents
On the subject of regulators, does anyone have experience mounting the Boyer Powerbox in an airstream vs inside the toolbox?
What were the observed differences?
Cheers
Paul

[PeteF]

Well Blown, I fitted mine under the seat to be sure, but Paul Goff, who knows a thing or two about auto electrics, says you can put the one he supplies in the toolbox. http://www.norbsa02.freeuk.com/goffyelectrex.htm

[Scalyback]

Location of rectifier... To quote a section from a Scaley epic...



On buying Thunderbolt, I had installed a Neolite reflector with a motovision lamp and it was a stunning success. It had to be about the brightest combination on the market and had served me very well at night. However when I had done the same for Tornado, I had overlooked a very basic and important point. Thunderbolt has a modern three phase electrical generator, where as Tornado had some old magnets and bits of wire spinning around inside somewhere.



The trip started well. The light worked and the ammeter indicated that the battery was charging. It is usual for the ammeter to show discharging when the engine is ticking over, whilst stopped at a junction, but it then picks up and goes back into charging as you start off again. but this was not happening. At every junction, the needle would slip further into discharge, and then back into charging, but each time it showed less and less charging.



By the time I was about ten minutes away, the needle was only going between big discharge and at best, small discharge. I was thankful for the high capacity Lithium-ion battery, but knew it was being drained at the similar rate of ‘a lot’ at junctions to ‘a bit’ when moving. Luckily, the battery held out, and by the time I pulled up at the meeting, it was already early twilight
The meeting went very well and when I left, the ammeter went straight into charge. things were looking up! Then they started looking down again. Not really knowing all the electrics, I stopped as the charging rate failed again, and tried to see what was wrong. Well, the regulator/rectifier which controls the rate of charging was missing. It should have been under the seat to keep it out of the rain, but allow air to circulate and cool it.



I did find it after a while. Some previous owner had moved it to the left side toolbox. It had been quite happy there, just running the LED’s and electrics, but the second I started to use the 55W headlamp, it got rather hot. With no air flow to cool it, it just kept getting hotter and working less and less. I waved air into the toolbox to help cool the regulator as I was not in a position to try disconnecting and moving it in the dark with only a torch. Cooling it would have probably been faster by throwing a couple of strips of bacon into the toolbox and cracking an egg over it, but alas, I was clean out of both.

[Adrian]

I'd hope the newer kit that Paul Goff and others sell would be better able to cope, but for preference I'd still want the unit where it could get a bit of breeze. A.