Newbie wiring questions

[kevinhall]

Hi,

Picked up our 72 crossover dormobile at the weekend and unfortunately ended up finishing the journey on a recovery truck Ran beautifully for 200+ miles, then ran out of battery.

Took the battery out on Sunday and hooked up to a charging system and had a look around at the general wiring to see if there is a problem and it looks a bit of a mess with half chopped loom everywhere, wires not attached to anything. So questions:

- the dynamo/alternator wires dont go to a regulator, is there a simple way of checking first whether it is a dynamo or alternator and secondly whether it has an internal regulator?

- the positive wire from the dynamo/alternator goes into a juntion box, which then splits the positive feed with one wire going to a box just at the right corner of the engine hatch and the second feed going to the battery. Is there normally just a direct feed from the dynamo/alternator to the battery. What is the box above the engine hatch? Seems to have the interior loom etc leading off it so is it just a junction box effectively?

Any help appreciated!

 

[Araon]

Any pics?

 

[buddysbuddy]

This is an Alternator.....

Does yours look like this?

As for you other Q, can you post some pics?

 

[kevinhall]

^^ yes looks like that and reading around, it only has two ouputs, one positive one to dash so must be alternator with internal regulator. Will get pics of the rest tonight light permitting.

 

[71Westy]

There is also a diagnistic test socket (yes, even in the 70s) where you describe - a box shaped connector where the diagnostics "computer" would have plugged into. I believe dynamo/alternator output was one of the things tested.

Nick

 

[kevinhall]

^^ it is indeed a diagnostic port - amazing what you find when you know what you're looking for. Ok, so even though loom looks butchered its making sense what it might be doing.

Here's a couple of pics:

I'm guessing that normally there should be two +ve feeds off the alternator as in buddysbuddy's picture with one going to the battery and the second to the diagnostic port. The rest of the wiring is probably the old regulator wiring from its pre alternator days?

 

[Tofufi]

I'm afraid I can't help with the wiring, but is is worth noting that your engine is missing a rather large (and significant) piece of the metal tinware designed to seperate the hot and cold halves of the engine. Also at least one small piece which goes under the cylinder head tin on the side photographed. You also don't appear to have a proper air filter?

Worth sourcing and fitting those bits ASAP, and checking you have the rest of the tinware & thermostat setup too, in my opinion.



Welcome to the forum by the way

 

[kevinhall]

^^ cheers. Tinware is just off so I can give it a good clean up and while I was checking everything over. It will be back in before I drive it again The airfiler setup seems to work fine but am on the look out for an original one

Anyone able to confirm how the wiring should be before I start stripping bits out?

Oh, and thank you for the welcome

 

[kevinhall]

Right, so finally had some time off to try and get things working and didn't go to plan! Battery charged up nicely, got the multimeter out and good 12.4 volts across the terminals. So popped the battery back in and got the bus fired up with a bit of a cough and a splutter. No generator warning light before start up even when earthed so thought this might be a problem but multimeter back on and getting 13.7ish volts across the terminal so alternator is putting out charge. Lights on, drops to about 13.3v across the terminals so struggling a bit. Thinking that it's probably the gauge of the alternator feed I decide to strip it out and put a new 120/20 alternator feed wire in it's place, straight from alternator to battery.

Now the muppet part! In putting the terminals back on the battery caught the spanner on the body work and shorted the battery. Alternator feed connected at this point. Now he fires up fine but just getting a steady 12.4v across the terminals so no charging. Could I have killed the alternator? Is there a fuse somewhere I could have blown? Or is my wiring simply wrong?

 

[kevinhall]

In case it helps anyone else, problem was the dash light. Had ruled it out as the old setup was charging fine and the light didn't work. But popped it to an auto-electrician who confirmed that my wiring was right, got the warning light working and now a good 13.7v across the terminals and 30amps so all good. Time to start enjoying the bus

 

[wilgartw]

yes the charging light is a vital bit of the circuit!

sorry to tell you this after the fact.