Ignition/Starter Wiring

[Lin]

For those who are more knowledgable than I regarding automotive electrical systems (that should just about include most of you!), I have a question.
The application is not a Healey but I figure someone here will know.


If I wanted to add a starter relay to the ignition/starter wiring system system. Should the relay go between the solenoid and the starter button, or should it go between the ignition switch and the starter button? I assume it should go between the solenoid and the starter button thereby relieving both the button and the switch. However, I know it is always better to ask than assume.



Thank you!


Lin

 

[Healey Nut]

A relay is an electrically operated switch . it has high amperage contacts and a coil energized by low amperage wiring which close the high amperage contact .

 

[healeyblue]

Lin
Yes between the button and starter solonoid.

 

[vette]

Lin, I believe I have a pretty good electrical background since I worked in the electrical industry for more than 40 years, but I have to ask a stupid question. Also I don't pay much attention to some of the newer schemes seen in the aftermarket. So here's the question, Why do you want to put an additional "Starter Relay" in a car. The Solenoid is already a Starter Relay. It allows a low current electrial circuit to pull in the High Current circuit from the battery main cable to the starter. Your ignition switch and starter button are already very capable of handling the low current pull in circuit. As it has been doing since the car was built. Now if your talking about a relay to start the car from a remote. I guess that is understandable. But then if you put the relay anywhere after the ignition switch you would have to leave the ignition switch on all the time to energize the relay. If you put the relay after a starter button, who's going to hold the starter button in when you want to use the remote. Just a few stupid questions. I haven't had my coffee yet. Dave.

 

[Lin]

Well, apparently no one sees a need for the starter relay. I was just thinking that it would be good to "relieve" the ignition switch with a relay, but I have been disabused of the idea.... I guess .
However, I did ask the question and I do appreciate the responses! I love this Forum.
Lin

 

[Keoke]

Well ole friend it might be an over kill but if you will feel better do it just like healyblue said.--Keoke

 

[vette]

Hi everyone. With respect to everyone, there is something about this concept that I do not understand. Typically, a relay is used to close a circuit that has higher amperage and larger wires, with a circuit that has much smaller amperage and smaller wires. The low side of the relay, or the smaller amperage side of the relay only have to pull in the coil of the relay which needs less amps than the circuit attached to the high side of the relay. You can see in my attached picture that that is just what your normal starter solenoid does. It is already a lower amperage circuit coming from your ignition switch to pull in or close the high amperage circuit between the battery and the starter.
If you install a relay in the circuit between the ignition switch and the starter solenoid, you would be using ANOTHER low amperage circuit to pull in or close an existing low amperage circuit. And the ignition switch would still have to be on, and the starter button would still have to be depressed to make power over to the starter solenoid.
If you used a relay to energize the solenoid from a completely different source than the ignition switch and the existing starter button, you would actually be building a completely parallel path to get power over to the starter solenoid. You would still have to turn the ignition switch on to get power to the coil so the engine would start. I don't understand why you would want to install all the additional electrical circuitry, wires , connections, and another component (the relay) that is effect would only by-pass the starter button. If your so worried about the starter button failing, put a new one in. see attached pic. I my be missing a whole different concept here, if I am please let me know. Dave.

 

[John Turney]

.... I my be missing a whole different concept here, if I am please let me know. Dave.

You're not missing anything except that the project has been canceled because there is no benefit.