Recent content by DHV90

Another small update. All battery and alternator terminals cleaned and reassembled, as well as checking resistance. Ran engine up, still no charge, substituted the indicator lamp/resistor combination for a much bigger bulb (21w indicator bulb I had lying around) on one alternator exciter...

Both no charge warning lights illuminate with the ignition but dont go off when the alternators are spinning. 24v light dims a little some times but never goes out, 12v stays on all the time The 12v exciter wire shows 1.2v when connected to the alternator but when disconnected it shows full...

That was my plan originally, i had the alternators off and rang round all the 4 or 5 local auto electricians, none of which have test rigs any more. I was told by all of them that with modern stuff if the alternator light comes on the dash they bin it and fit a new one, no point testing and...

So, at the regulator end of the F wire with the ignition on I have full battery voltage, showing there is full power going through the Armature wire, through the slip rings and back through the field wire with correct resistance. There is also switched live with good power at the H/M/L terminal...

Awesome, I had the direction of the F cable confused in my head, think its falling into place so I'll go back with the multimeter and do some more digging Thanks for that, again, its really helped!

Amazing thanks, this is really helpful sorry for taking up so much of your time. Does this mean that I, in theory, should see a voltage at the F terminal on the alternator when the field cable is disconnected? So the power to excite the coils probably comes from the alternator diode pack...

thanks for that Ill read through those diagrams today and try and make sense of it. I believe my setup is what is shown in the attached image. WL terminal definitely has full battery voltage, with almost nothing at F. I need to go back with the multimeter and do more tests, if you have any...

Cant see why a 1w bulb would reduce 12v down to 1? Plus the 24v side runs through an identical circuit and has full battery voltage at the end of the field cable in the engine bay, so theres got very something wrong right? Poor choice of wording as well, meant more along the lines of a modern...

Awesome thanks all the has really helped my understanding. Obviously this is not where the problem lies but I can move on to other bits without doubting myself if that makes sense. Thanks for the input everyone every post has been helpful. I've started digging in further, the 24v alternator is...

that makes sense now, thank you both!

Hi Richard, in that scenario with equal value resistors both sides are the path of least resistance, im curious of what happens when unmatched resistors are in parallel, and how much the current is split between them. Hi Vic, again, Im quite happy with all of that as has been explained before...

I've used a 50 ohm big ceramic resistor on the 12v side and 150 ohm on the 24v side both rated for up to 50w. I understand the logic well up until the parallel circuit part, I thought that current would follow the path of least resistance so struggling with why a parallel circuit is needed. Im...

Thanks Vic, i understand those things, the bulb in question is a filament bulb but a tiny one that runs on a fraction of a watt, not an LED but not enough to excite the alternator (from what I understand) Im just confused about why the resistor needs to be in parallel to the small filament bulb...

Ive just tried the resistor in parallel to the bulb with no joy, is it definitely meant to be wired in parallel to the indicator lamp? My electronics is really basic but I thought that the current would favour the path of least resistance, and basically bypass the resistor? Vas - how did you...

Bev D belongs to JD Marine