[MYGOAT]

I have been having issues with a hot start problem. Muffled click click, but when cars cools down a bit starter cranks like a dream.
Amongst checking cable condition, upgrading cable size, good earths and using mini starter motors, there is a lot mentioned about using a Ford style remote starter solenoid. I have had a look at how these are wired up and don't really understand where the benefit comes from.
I have plagiarised a diagram from the net to help.
Obviously you still need to activate the original starter mounted solenoid as this is what throws out the drive pinion and then shortly after closes the main contacts which power the starter so that it spins the pinion. This is set into motion when the S terminal wire is made live when you turn the ignition switch to the crank position.
So, with using the Ford remote solenoid you jump the starter's S terminal via a short link to the large starter stud and the original wire that used go to the S terminal on the starter now goes to the Ford remote solenoid S terminal.
Apart from the S terminal wire being relocated everything else seems to be the same, electrically speaking. Does all the benefit come from the S terminal wire being kept cool?

[george kujanski]

The GM solenoid has two windings within it, a pull and a hold winding. The pull winding does the initial job of pulling in the Bendix drive, but to do so draws about 40A from the purple wire/ignition switch. Over time, these connections may be loose or corroded which adds resistance to that circuit, reducing the current available to the pull winding. Compounding the problem is as the solenoid gets hot, it's resistance goes up too, further limiting the current it can draw, thereby limiting the force with which to pull in the Bendix.

Using the external Ford-type relay, (it's not really classified as a solenoid), the path for the GM solenoid pull current is very low resistance, coming thru the large cables, not having to come from the bat thru the firewall, thru the ign switch, thru a neutral start switch, thru the purple wire to the solenoid.

The Ford relay only needs an amp or two to trigger it, which the original solenoid circuit has no problem delivering.

There is the additional benefit that the bat cable to the starter is normally electrically dead, only live when you start. Considering it has to wind around the exhaust manifold, etc. it's an added safety.

George

[MYGOAT]

OK, Thanks George.
So, it's all about getting as much of the full battery voltage to the S post on the starter motor, which it now will due to getting power straight from the starter motor battery post right next to it.
I'm off now to buy one of these Ford "relays".
You're a champ.

[george kujanski]

Early in the day for you folks down under, no? I actually have some relatives in Brisbane.

George

[MYGOAT]

Nope, its 2.30pm.

I am down south in Melbourne. Rather be in the Brisbane area (Gold Coast) a bit warmer up there.

[grandville455]

Was looking at this, and wondering what happens to the I wire then that goes to solenoid? Nothing? Any ford relay will work? No special part number etc?

[Overkillphil]

We source out the 73 Ford Pickup relays as the word in the group is they are better for some reason.

[george kujanski]

I believe the I term goes live when the Ford starter relay connects. It can be used to feed battery power to a points-type distributor during cranking, same as the "R" term on a GM starter usage in Firebirds.

George

[Sirrotica]

George, that's exactly the correct usage for the I terminal, to bypass the resistance wiring going to the ignition system giving 12 Volts on cranking to boost the output of the ignition system. When Ford switched over to electronic ignition the I terminal was deleted from the later model relays.

[grandville455]

So All A guy needs to do then is exactly like in the pic above? Seems much simpler than the way GM has it stock. I thought I had two wires on My Batt terminal down at the starter? I also thought I had one on The I side of the solenoid too? Can't remember right now. Where would that extra wire go then? My car used to be points originally. This is what i seen listed for a 73 f100

BWD - Relay Solenoid
Part # S63P

[george kujanski]

You also need to move the second cable from the starter solenoid big bolt to the battery side of the Ford starter relay. This cable is the battery feed to the rest of the car and the alternator connection.

In the above scheme, ALL the wiring down at the GM starter will normally be dead hence the necessary movement of the battery feed to the battery side of the Ford relay.

I prefer this setup also. The only downside is exposed battery connections at the relay; be careful of wrench dropping; a safety cover is a good idea.

George

[Sirrotica]

Originally Posted by grandville455

So All A guy needs to do then is exactly like in the pic above? Seems much simpler than the way GM has it stock. I thought I had two wires on My Batt terminal down at the starter? I also thought I had one on The I side of the solenoid too? Can't remember right now. Where would that extra wire go then? My car used to be points originally. This is what i seen listed for a 73 f100

BWD - Relay Solenoid
Part # S63P

Darby, I see you've never worked on anything with a Lucas electrical system on it if you think GM made it harder than it needed to be.....

[george kujanski]

Three positions on a Lucas light switch: off, flicker, and dim.

George Lucas invented the short circuit, then improved upon it.

George

[regamble]

Correct, getting the solenoid (relay) away from the heat is a major bonus, but also getting it away from oil leaks etc. As pointed out yes, please make sure to move the main accessory lead from the GM starter to the Constant Hot side of the Ford style solenoid. Look under the hood of any old Ford and it'll make perfect sense.

The "I" post on the Ford solenoid had been used for a couple reasons. One, as noted, it was used as a 12v bypass to the ignition system on cars with a resistor wire dropping the voltage to the ignition down to 7vdc while running. This keeps the coil a lot cooler and keep you from burning up points. Also, on some Duraspark systems, the "I" post is used to tell the ignition control module that the car is in crank mode which will then retard the ignition 10° for easier cranking. After a short time, Ford used the crank signal to the "S" post to retard the timing in the Duraspark box.

[BVR421]

Wasn't Lucas was better known as the Prince of Darkness?

OK. Somewhere, sometime in a land far away and long ago, I saw a Ford type relay, in fact I think it was on a Ford pickup or on a Falcon, that had a energizer button on it. The push button was right on top where most of the others have a big raised dimple. That would be a very handy thing to have what amounts to a remote starter button right there under the hood. Of course anyone with a Ford knows you can just short across the bat to primary and energize but having a button would be too cool. So.... does anyone know where to find the relay with that button?

[regamble]

BRV421, those are a constant duty relay, used for older winch setups on old non-remote winches (at least as my fading memory serves). I will look around and see if I have one, I used to. There was one on my 79 Bronco when I bought it. Otherwise, you're not looking for a "Ford Solenoid" you're looking for a Constant Duty Winch Relay. They are usually all metal housings instead of the plasic like they would sell you for a pickup. So, maybe try ebay or your local farm and ranch store.

[Sirrotica]

The constant duty relays have 2 sets of windings. One high draw, high power set to pull the pole piece spool in, once the pole piece spool shifts it breaks one set of contacts and closes another set. The second set is energized to keep it pulled in without as much draw and heat being given off. If used only on the primary winding under constant duty they will soon overheat. Many types of battery powered aerial lifts as well as battery powered forklifts use them if your in search of one. Make sure of the voltage because they come in different voltages depending upon how the batteries/battery are used in a particular machine and what voltage control circuit is used.

[grandville455]

Okay going to do this today, What happens to the I wire from the solenoid? Do I not need to use it at all with the ford solenoid Just cut it ? All I need to do is run a battery cable down to the big bolt and then run a jumper from that to the S terminal correct? then run the smaller battery wire that was on starter to the battery side of the solenoid and the original s cable to the s on the ford correct? Anything else?

[grandville455]

Success!! Hopefully one less thing to worry about this summer!

[johnta1]

Congrats!


If you have HEI, you don't need that wire to the I side anyway.
You should have 12 volts all the time to the ignition.
(not just on cranking)