Alternator connections

[arcturus]

Putting everything back together. The photo I took of alternator connections doesn't show clearly where the black from what looks like to me a suppressor connects at the other end. It looks like the big nut and screw further down at the back. Can anybody please confirm?

[Ron Kwas]

Arcturus;

I am strictly deducing here, but I would expect the heavy Red wire to be the Alt output, going into the sleeving and off to the vehicle elec sys...so I would expect the heavy black wire also going to the suppressor to connect to the Alt output terminal (possibly labeled B+).

Green wire is Filed wire connected to DF term.

Red Wire is probably voltage sensing wire.

I also suggest having a close look at the vehicle wiring diagram where you should be able to confirm this.

Good Hunting!

[arcturus]

OK, problem solved. I was tired and not thinking straight. Fastened suppressor to wrong place, terminal instead of long bolt. Should have called it a day earlier.

[arcturus]

Got engine running but noticed alternator light stayed o. When I checked the wiring at the alternator I saw that the black wire from the suppressor had fried (see pic') As the connections are as per original i am assuming that somehow the suppressor had shorted out. if this is the case can I do away with the suppressor and connect red directly to +B. All thoughts and advice appreciated. BTW The radio is not connected. I never listened to it. preferred the music from the engine.

[Derek UK]

That looks all wrong to me and you appear to have power and earth on the same connection, hence the melt down. The suppressor shouldn't be part on any circuit but, I believe, just placed between B+ and a suitable case bolt to damp out any stray sparks. Not essential though for the alternator to work.

[arcturus]

So what goes to B+ ? I don't have a clear circuit diagram. It's my i44 B20b. 1969

[Ron Kwas]

arcturus;

STOP!... and understand thie following:

The heavy gauge Red wire is exhibiting signs of having been extremely hot also (partly melted and disformed insulation)...this indicates excessive current was flowing...where to is the question!

I only now see that it is a two terminal suppressor...

If Black wire was connected to B+ (Alt output) as I suggested, I don't believe the Suppressor is the issue...it is in series with the high current, and not only a Capacitor which would be from B+ to chassis (and which would be a single terminal, with Housing connected to Alt Housing), but a series Pi Filter (with two connections in addition to chassis connection). There should be NO direct connection between either of the two terminals of your Filter to Chassis (Disconnect from vehicle wiring before checking!)!

Here are the two arrangements:


What is clear to me is that a short to chassis (or an extremely heavy Load) exists in this elect sys, (and Black wire happens to be the one which fused open first!). I don't believe the Filter itself has a problem...but it and both associated wires passed excessive currents!

There exists a big problem in this elec sys! Since this high power wiring is not fused, melting insulation is the last step before an electrical FIRE! BEWARE! Engine can be run with Battery supplying power, but I strongly recommend disconnecting Alt output until you figure out what is wrong before connecting up Alt output again! Refer to Wiring diagram for this vehicle, and if this is an Alt conversion, refer also to Alt wiring of vehicle from which Alt originated!

In thinking about it some more...it sounds like a short to chassis may be present within (or at) the Alt (melted wires were passing Battery current to it)...CHECK THAT ALT, and associated connections!

Good Hunting!

[arcturus]

Disconnected and removed suppressor from circuit and connected directly to B+ stripped back sheathing but found no more evidence of shorting, the black must have acted as a fuse. Started motor briefly but red amp light stayed on. so switched off and disconnected battery. the heavy red disappears behind dash, probably ignition switch? Hope it's not alternator. How do I check the heavy red for short circuit. Have multi-meter but not sure as to setting for short circuit setting

[arcturus]

Wire from B+ goes to solenoid and from there to battery. Also on same terminal lead from ign' switch. The connection at solenoid looks dodgy. seems to connect directly against solenoid body which would cause a short. Shouldn't there be some sort of insulation from casing or is that part made of insulating material?

[arcturus]

Up date. Removed the suppressor and connected the red directly to B+, fitted a large rubber washer on solenoid connection so that the connecting wires don't short out on casing, re crimped all connections. The problem seems to be solved. I have had the car running for some time, constantly checking for cables warming up. Everything seems OK. No problems that I can see.The charge light goes out now when the engine runs.