Help with GM starter/relay problem

[zubzub]

all my alarm stuff is long gone and the work arounds are haunting my system.
In this case though I  am referring to the old relays jsut being degraded.   When I bench test the old relays they are basically operational but very  "leaky".  Voltage drops through  the main coil  and voltage where it shouldn't be, and this is after tuning them "by the book"

[Barn Owl]

Someone educate me here. After looking at the wiring diagram on the 4106, it still looks like that relay cuts out the alternator via the rectifier. In addition to shutting down extra loads why would it also go to the rectifier? The relay I am referring to is called a "generator/starter cut out relay". One never can learn too much about vintage coach electrical systems.

[TedsBUSted]

Someone educate me here. After looking at the wiring diagram on the 4106, it still looks like that relay cuts out the alternator via the rectifier. In addition to shutting down extra loads why would it also go to the rectifier? The relay I am referring to is called a "generator/starter cut out relay". One never can learn too much about vintage coach electrical systems.

Okay the curiosity got to me, so I looked.  I don't see a generator/starter cut out relay or  rectifier in the starter circuit of my  4106 schematic.

Are you possibly misreading the schematic's STARTER CONT & GEN RELAY to read as STARTER COUT & GEN RELAY?

At least with the 4106 schematic I have, to stop alternator from charging, which as mentioned isn't an issue at cranking speeds,  the regulator's Pos terminal would need to be opened by Regulator Sensing Relay. However, during cranking the regulator Pos circuit is supplied at least some current from Gen Tell-Tale resistor, to connection 57, to Regulator Sensing Relay's  S terminal, through closed contacts, to B terminal, and then to Regulator Pos terminal. But again, since alternator load is a non-issue at cranking speeds there apparently was no attempt made to isolate the alternator during cranking. Anyway, that's my take from the schematic I have.

I'm curious where a rectifier seem to come into play with your circuit? And, how the alternator cut out?

Anyway, I'll bet that most of these complex starter circuits were "streamlined" long ago. It sure seems like this circuit could have been greatly simplified by using a pressure switch at either fuel or oil pressure.

Ted

[GM0406]

The '04 I have is using two Iota Converters suggested by Tom.  I still get outfoxed by Murphy's causing trouble from time to time.  Of course your's truly left the boster box plugged in on them and burned up the batteries in the '04!!!  Don't do that!!  The little booster boxes work great when you shoot yourself in the foot like I did a couple of days ago when the shower light didn't work.  Until we were on the road and then it came on.  But we didn't see it as the shower door was closed and not see through.  Well after docking without connecting to land power, the batteries were run down in two days.  So when we tried to leave I was thankful for the little black box with the green light and telephone connector which when plugged in gives fast charge, and within 20 minutes we were able to start and go. 

With these Iotas, both coaches are coming up on 5 years for batteries with no problems at all.  And both coaches start like champs every time.  Got to believe this saves starters.   And no battery water loss either.  Amazing!!  Bill T.

[pvcces]

I'm glad to see you are having good luck with the Iotas, Bill.

Tom Caffrey