BIS ignition fault?

[Gadge]

Decided to fit my new distributor today. I've set up the points and fitted it in only when I did a static set up test on it there was no power going to the points? So I checked to coil wire to the distributor and there's none there too so went to the coil and sure enough there's none there too at both sides. Where would be then next port of call as I'm out of ideas?

[Gadge]

Ok I now have power to the coil - not intirely sure why the test light didn't respond earlier but it does not ..... Abet very dim leading me to think that perhaps the battery is flat. But still no power to the dizzy 

[ChrisRLewis]

Maybe that the test light is dim because it is a ballast resistor circuit to the coil, therefore the voltage is much lower.

[Gadge]

Ah I see. Thought it would still be a stronger current than that though? The distributor is a marelli one so I'm wondering if im doing something wrong? I've been searching for a live current in it but just can't seem to find one.

[Gadge]

Ok my ignition woes continue but I'm a little further to the cause of the problem. The coil is fine but still no power to the marrelli dizzy so refitted the old ZELMOT and would you "Adam and Eve" it, I got power. So I removed that and held the marrelli in my hand and connected the LT wire and it it got power. Result .except that soon as I touch the marrelli to the engine there's no power. So I did what anyone  would do in my position who knows very little about auto electrics....... I boiled the kettle and sulked

[gammakeith]

The distributor basically earths the coil controlled by contact breaker.  You will only see voltage (or a lit timing light) with the points open.  As soon as the points close there should be little or no measurable voltage at the LT wire/contact breaker.  If you are testing with the points open and you have current flow then the condenser in it might be shorting out (or possibly the points are assembled wrong).  You will not see that until you complete the circuit when the current flowing through means that the voltage now drops right off (it won't be 12V anyway due to ballast resistor).  If the points are open and the condenser is disconnected it should make no difference if the distributor is earthed or not.  It would be so much easier with a multimeter as you can check actual volts and resistance 

Keith

[Gadge]

Damm that's good stuff Keith I'll get on that ASAP. The points in the marrelli system seem to look like they are pre assembled on like a frame that just drops in to the dizzy body hence why I can't get my head around them being wrong but the condensers a great shout so I'll look into that

[gammakeith]

The "moving" contact breaker point has to be insulated from the pivot. They normally run in an insulated bush arrangement.  It might be worth double checking that all the washers and bushes look to be present as that could be the source of your short to earth.  However, if its a replaceable unit then that does seem unlikely.  However, it will be worth checking that the LT wire is not damaged where it passes though the distributor body and that the insulating washers are present where the wire (and condenser lead) clamps to the contact breaker points (the current can short to earth via the spring otherwise).  Condensers don't usually short out when they fail but you never know.....

Good luck!

Keith

[Gadge]

Again, thanks Keith this information is valuable too me . I had a quick look last night again and did a continuity test on the dizzy and its showing that there's a current flowing though it regardless of weather the points are open or closed so we are defiantly looking at an earthing issues. The LT wire is split as it goes into the plastic clip on the distributor body. It's not touching any part of the body so I'm not convinced that it could cause such a big short but ive got another one on its way. I've put a photo of the points and condenser that's it currently uses

[gammakeith]

I've not seen a unit like that before but you are getting there.  Try disconnecting the condenser at the points and see if the short goes away.  If it does then its the condenser!    If not (which I suspect) then reconnect condenser and disconnect LT wire to the points at which point the short should vanish.  If it doesn't then it must be shorting as it passes through the distributor (or somewhere close).  If the short goes when you disconnect the LT lead and the contact breakers are open then there is a fault with the points unit - probably the insulation for the moving contact breaker.

Keith

[gammakeith]

On further inspection of the picture, its possible that the clip that connects at the contact breaker has rotated so that it is touching a metal part on the distributor.  If so, that would cause your issues and would be an easy fix!

Keith

[Gadge]

Ok there's now light at the end of the tunnel. I removed the points today and found some damage. Have a look at the picture below - bearing in mind this it suppose to be new.



You can clearly see it at the bottom of the moving part of the points (sprung side) is bent out and its this I belive that was touching the rivet on the base plate and earthing out. Also once removed I tested the points in the close position and still no reading on the multimeter. So must be gunked up. It would seem someone has had ago before I had it 

[dombooth]

Give me a call pls mate.