Electrical issue under the bonnet + small fire!

Post by **HotRodMorrie** » Sun Jan 27, 2008 7:51 am

Hi all complete greenie here. I bought myself a '53 morris the other day and am having some electrical issues with it and i know very very little about electrics. I bought the car as a project for myself to learn how to do basic mechanical things on and seem to have gotten more than i bargained for.

Yesterday i had the car idling in the driveway, after about 2 minutes i smelt a nasty acetone sort of smell coming from under the bonnet then black smoke. I immediately turned off the motor and isolated the battery. Under the bonnet there was a small fire which i promptly put out. The following pictures are the item in question, i have no idea what this is or what purpose it serves. It looks pretty dodgy to me!

Can anyone enlighten me and give me some advice as to what happened, and how to fix it. Thanks in advance.

One thing to note is that the soldering on the side looks a bit dodgy, wondering if an earth wire or something came off it?

Post by **Orkney** » Sun Jan 27, 2008 8:00 am

where do the wires go to from the relay underneath ?
do have a crazy stereo or lots of watts of lamps on there?

Post by **HotRodMorrie** » Sun Jan 27, 2008 8:02 am

No stereo at all, nothing that would suck watts. Checking the wires out now.

Post by **HotRodMorrie** » Sun Jan 27, 2008 8:25 am

Wires from the black relay are all related to the headlight. Blue to alternator, so far ive only been able to backtrack the thick red wire to the fuse box, having trouble from there. Will have to take off the dash etc to find him.

Post by **Orkney** » Sun Jan 27, 2008 8:29 am

Hmm, well someone will be along who will hopefully know (when they get up that is LOL)
dash - if you take out the pod behind the steering wheel you can see and get to quite a lot from there.

Post by **8009STEVE** » Sun Jan 27, 2008 9:05 am

It looks like the a voltage stebiliser of some sort. The blue wire should go from the alternator direct to the battery IIRC.
I cannot think why it should be stabilised, then go to the fuse box.

Post by **8009STEVE** » Sun Jan 27, 2008 9:10 am

Check this
http://www.mmoc.org.uk/index.php?name=P ... ic&t=16856

Post by **Orkney** » Sun Jan 27, 2008 9:12 am

Could it be someones attempt at a fix of a problem with that alternator that's on there? Could be its too powerful or something?

Morrie Mogs had a dymamo as standard - an alternator is a mod, (not an uncommon one at that)
Can you find out what that alternator is to make sure its the right one?
Should think it would be worth testing it too - could just be its on the blink and threw out too much power causing the metal thing to fry?
Could also be that the metal thing just fried of its own accord?

Post by **Alec** » Sun Jan 27, 2008 8:39 pm

Hello Orkney,

electrics don't quite work that way. Alternators (or dynamos) don't give out any more power than they are asked to. Too large a unit would not be a problem in its self. The problem with diagnosing this is non standard wiring colours and knowing what modifications have been done.

I'm afraid it is a matter of tracing the defective circuit to establish exactly what it is connected to.

Alec

Post by **bigginger** » Sun Jan 27, 2008 8:46 pm

It *could* be somebody's attempt to emulate the factory fitted alternator, which had a few additions to the dynamo models. There should be a diagram in your handbook of that, which might be worth a look.
a

Post by **bmcecosse** » Sun Jan 27, 2008 9:45 pm

What's the engine ? Not A series !!
Any clues from the writing on the top of the silvery box ? Could well be something to do with alternator control.

Post by **bigginger** » Sun Jan 27, 2008 10:01 pm

Good point. It looks like I remember the electronic ignition packs being like years ago as well

Post by **HotRodMorrie** » Mon Jan 28, 2008 1:18 am

Right, found out that its a Bosch RE55 External Alternator Regulator. Obviously ill have to check out what sort of alternator it has now. The car has been running for ages without issues so im guessing the regulator just packed up.

The fact that it caught on fire is very disconcerting though. The car is going to the mechanic on monday so i guess ill chuck another regualtor in it and then get the mech to check it out for me.

Apparently the RE55 is earthed via its mounting points, im wondering if somehow it became un-earthed causing it to massively over heat.

Post by **bigginger** » Mon Jan 28, 2008 1:26 am

Or, if it needs a new alt, it'll have one built in
a

Post by **Matt** » Mon Jan 28, 2008 6:14 pm

I *think* that might be triumph 1500 unit, ala 1500 midget

Post by **bigginger** » Mon Jan 28, 2008 6:21 pm

Aha. An engine famous for bullet proof reliability and sheer power... ;)
a

Post by **WPR678B** » Mon Jan 28, 2008 6:51 pm

Looks like a Datsun unit to me judging by the rocker box. Probably wrong though!

Post by **bigginger** » Mon Jan 28, 2008 7:05 pm

Seems more likely - but I've never looked at one so can't confirm

a

Post by **bmcecosse** » Mon Jan 28, 2008 9:29 pm

Don't think it's a Triumph engine!
As for this problem - maybe easier to just get a suitable alternator at the scrappy - one with all the gubbins inside.

Post by **HotRodMorrie** » Mon Jan 28, 2008 9:33 pm

I was told that the engine is a nissan 1200 motor. Haven't really spent much time messing around with it yet.

As for a new alternator, i think that might be the go but ill look at that when i get a sparky to check out the wiring.