Is the starter soliniod reversable? And what is the point of the ignition spot on it? What purpose does this thing serve? Thanks!

Clayton

 

Clay, what do you mean by reversable? Its purpose is to make the electrical conection between the battery and the starter. When you turn the key to the start postion, or push the start button, which ever one your starting system uses, a magnetic switch inside the soliniod make contact and sends power to the starter. Ozzie.

 

Ozzie has it right. You need a BIG switch to handle the amount of amperage the starter draws. The solenoid is just a big relay - the starter switch on the dash sends a smallish current through the solenoid coil and the magnetic field pulls a steel rod with a big copper contact across two other copper contacts inside the housing.

You probably wouldn't want a starter switch on the dash that was big enough to handle all the current for the starter. First, it might take a bit of effort to engage it and second, you'd have to run big cables all the way to the dash from both the battery and starter. There are a lot of other reasons to use a relay close to the high power devices (battery, starter) and then control it remotely with a low power switch. Headlight relays are another example.

As far as the ignition terminal on the solenoid, well, that's kinda interesting. On a 12 V system, the coil and points are actually designed to run on about 6V. A resistor is put in series with the points and coil so that, under normal running conditions, the voltage across the coil is half the battery voltage - about 6V.

When you are starting the beastie however, the battery voltage may drop a LOT - especially in cold weather. That resistor in the ignition system is cutting the 6 or 8 V from the battery (when cranking the engine) to only 3 or 4 V. So now your ignition system doesn't have the voltage it needs to give you a good spark when starting the engine. That's where the ignition terminal on the solenoid comes in.

When you are cranking the engine to start it, the ignition terminal on the solenoid gets full battery voltage through connections on the inside of the solenoid. The solenoid ignition terminal should be connected to the coil to provide full battery voltage ONLY WHEN CRANKING THE ENGINE. If you put the full battery voltage across your ignition all the time you'll burn out points (and maybe the coil too) very fast. Basically, the contact bypasses the resistor in the ignition circuit so you get full battery voltage at the coil instead of only half.

You other mavens chip in here. I likely got at least one or two things not quite right and I'm not familiar with the 6V systems. Do they work the same way?

 

why do you want to reverse it

 

George, learned something about the ingntion post on the solinoid switch from your reply.thanks for sharing your knowledge.Wayne..

 

No, no, no. Revese the poles as switching the sides for the batterie cable and starter cable. I want to reverse it because I've moved my batterie & soliniod and using the same cables the thing fits better with the cables on the opposite ends then the way it was.

Thanks about the ignition spot answer. That's sounds really familar. I think I knew that when I wired it, but time has passed and I forgot. Thanks.

Clayton

 

it's just a big relay, i don't think it maters which way the current flows

 

It doesn't matter which way the current flows through the solenoid but I believe there are internal connections that need to be correct to work. My "original" 6V solenoid didn't have an ignition connection. The coil part of the solenoid "relay" came out to the small wire going to the start button and was internally connected to the battery post, thus having -6V on it. The start button simply grounded (+6V) this terminal completing the circuit and energizing the relay. If you reverse the power connections, you won't have voltage to close the solenoid.

When I converted to 12V neg ground, my new solenoid's internal coil was connected to the mounting frame. I had to supply +12V through a new starter button to get the solenoid to close. If I reverse the power connections I think the ignition connection will be on all the time. Anyway, use an ohmmeter to check the internal connections. Your solenoid may be different.
J

 

Question there seems to be two differant coils offered some have an insternal resistence of 1.7 ohms and others have .6 ohms do you know what the difference is??? Ed ke6bnl

 

No, I don't but I bet some of the other folks can help with that question.

 

ignition terminal on the solenoid


george

if i understand your post, the 6v posi. ground system do not have this connection. i just put a new 6v solenoid on my 49 and it did not have this and it woks great. is this somthing only for thr 12v guys.

thanks