tach pegs and smoke from the cluster

[Tscott38]

Been test driving the 68 440 w/ electronic ignition kit and an old-style voltage regulator ( I think) lately and i've driven it about 50 miles total since putting it all back together.  Has been performing well - until this weekend.  While driving i noticed a very slight (millisecond) miss, during which I noticed the tach pegged, the ammeter pegged, and a very small puff of smoke comes out from behind the cluster.  It just as quickly went away and I kept driving.  Happened once again a mile later, and I kept driving - happened a third time another 2 miles down the road - the ammeter pegged from one end to the other of the gauge and the engine died.   Key wouldn't turn the motor over - fusible link was burnt in two. 

Once home, I took the bulkhead connector off and saw that the black wire from the alternator was heated up to the point where it fused itself to the bulkhead connector.  So the two wires that got hot were this one and the fusible link.

Noticed that the BATT post on my alternator (dual field w/ one field grounded) was slightly loose.  This is the post that has two wires going to it with a black splicer/connector at the post.  Noticed a bit of White powdery residue on the black boot when I took the alt off - not sure what it was or if it means anything, but it was an observation.  That same powder was evident inside the alt where the windings were.  The post was not real loose, but not snug - it moved around a little and it shouldn't have. 

Pulled the wires out of the bulkhead disconnect out from behind the cluster and saw that that black wire that goes from the alt to the ammeter I think had a heated glossy look to it - and the insulation was gone on a section just past the terminal block - about the size of a pinhead.

  I know I have a short somewhere , but why did the tach peg?  I have not looked at the voltage regulator yet. 
Thanks for any replies.  I sure do appreciate everone on this board.  I've learned a lot. just from reading. 

[Dino]

The white residue is typical for a loose connection.  Tighten it all up, replace the wire and whatever else got fried.  Pull the cluster to see what's going on there and while you're at it, replace the cluster coltage regulater for a solid state.  I run the Ivr4 from RTE specialties.

Not sure why your tach pegged, is it still working properly?

[Tscott38]

Thanks for the reply.  The cluster voltage regulater is already a solid state -  my gauges are all new, as is the circuit board.  the voltage limiter (i think thats what you mean) is built into the board.  The gauges all still worked when it died on me 2 days ago.  I believe the smoke was from the black wire coming from the alt thru the bulkhead disconnect. 

The regulator under the hood is what I believe is for an older alternator.  the alt charges fine - been gettign 14.5+/- out of it - but I don't know if that could be part of the problem, or that loose post on the alt.

One thing I forgot to mention is that wire had a splice on it just inside the bulkhead and was a huge glob of solder - it wasn't corroded or anything, just a nasty splice.  DOnt know if that could have caused some form of overload or not.  that wire got real hot and fused to the plastic bulkhead.

Everything else seems OK.   

thanks again

[W4ATL]

A solid state voltage regulator for the battery is recommended when using solid state ignition. The RX346 from Year One is a drop in replacement that looks like your mechanical regulator. Check for any nicks on the wire going from the voltage regulator to the field of the alternator.

[Tscott38]

Thanks.  I said that I had an old style regulator, but after looking at the RX346 on Y1's site, now I'm not so sure.  Mine looks like that, but you take the cover off and it had red wire windings, and what looks like points of some kind  - that is the old style isn't it?  Solid state is transisitors and the like.  Pardon me, but I know nothing about electronics.  Nothing arc'd in it though - it has a good ground - still looks like new inside.

[Dino]

Thanks.  I said that I had an old style regulator, but after looking at the RX346 on Y1's site, now I'm not so sure.  Mine looks like that, but you take the cover off and it had red wire windings, and what looks like points of some kind  - that is the old style isn't it?  Solid state is transisitors and the like.  Pardon me, but I know nothing about electronics.  Nothing arc'd in it though - it has a good ground - still looks like new inside.

Yes you have the original style.  The solid state limiter looks the same, just doesn't have the date code but they look near identical.  You'll want to install a solid state limiter though to rule out future issues.

[W4ATL]

Thanks.  I said that I had an old style regulator, but after looking at the RX346 on Y1's site, now I'm not so sure.  Mine looks like that, but you take the cover off and it had red wire windings, and what looks like points of some kind  - that is the old style isn't it?  Solid state is transisitors and the like.  Pardon me, but I know nothing about electronics.  Nothing arc'd in it though - it has a good ground - still looks like new inside.

You have the old mechanical regulator. The RX346 is designed to look like the mechanical. I would put in an electronic regulator to make sure the old one is not sticking. It is recommended with solid state ignition. It may not be the problem but you need to have it. That is why I was suggesting making sure the wiring is good from the voltage regulator to the alternator.

Something could also be shorting out inside the alternator - from the BATT terminal on the alternator to ground. I am recovering from an internal short that occurred in my alternator but it failed with a short all the time. I think I saw the ammeter peg over for a short period of time before the major failure but it was so quick I couldn't really tell what was going on. Not sure if it was giving me a clue to imminent failure.