Remote Starter Solonoid

[bmfm64]

So I added a Ford starter solonoid to my SBC starting circuit and everything works fine, I just don't understand why? I ran the main wire to hot side of solonoid and then to the starter. I pulled the S wire off the starter and put it to the S on the ford solonoid then ran a 6gauge wire from the momentary big lug to the S terminal on the starter. Works fine and all that but how does it work? the starter is still just as hot as before? I don't get it. Am I missing something?

[MikeyMan]

As I understand it, you get more "juice" to the solenoid on the starter. This helps make sure it engages the starter.
Originally, you have just a 12 gauge wire to your S terminal. Now, you have a 6 gauge wire. This should provide less voltage drop, thus extra "juice" to kick in the hot solenoid.

[bmfm64]

Thank you. I just don't get how 12v in a 12gauge wire is different than 12v from a 6 gauge wire? Weird.

[speedygonzales]

"gauge" of the wire has nothing to do with voltage. It's a current thing. Think of a small wire as a small hose. The smaller hose will not allow as much water flow as a larger hose.

Current which is measured in amps. Each size wire has an "amp pacity". Which you can look up in charts. You may see it most often on extension cords.

[Axle]

Also, the hotter that the wires get, the less current capacity (resistance of the wire increases. The smaller the wire, the more pronounced the effect).
Also, as the solenoid gets hot (heat soak for instance), the more current is needed to activate it.
If the activation current the solenoid needed is higher than what the stock wire can deliver it won't start. However, that is enough to activate the ford solenoid, so all the parts function and you can drive away.

Alex.

[bmfm64]

Thanks guys, I get it now. And I haven't had any trouble since installing the remote solenoid.
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[fixit-p]

The remote solenoid works because it addresses the real problem with a heat soaked condition (the purple S wire). A hot solenoid increases in resistance so it will actually draw less current not more (resistance limits current flow). The original S wire (purple) as it gets hot will also increase its resistance value limiting current flow to the solenoid when the S wires resistance gets high enough the solenoid wont engage.

[davebloomer]

Originally Posted by bmfm64

So I added a Ford starter solonoid to my SBC starting circuit and everything works fine, I just don't understand why? I ran the main wire to hot side of solonoid and then to the starter. I pulled the S wire off the starter and put it to the S on the ford solonoid then ran a 6gauge wire from the momentary big lug to the S terminal on the starter. Works fine and all that but how does it work? the starter is still just as hot as before? I don't get it. Am I missing something?

I have replaced one starter already this year and my new one is starting to sound bad on cold start and won't work on hot start so I suppose I am going to have to do this to mine. Thanks for the info.

[fleetsidelarry]

if your starter is "sounding bad" when cold, then the remote solenoid won't cure the problem, although it may help the hot start, depending on what the symptoms are then. if I understand correctly, the problem with a "hot" solenoid is that it doesn't engage at all, resulting in a "dead" battery "click" sound and the starter not turning over at all. if your starter is dragging but turning over, then I think the problem is elsewhere in the starter or the cable connections.

[davebloomer]

Originally Posted by fleetsidelarry

if your starter is "sounding bad" when cold, then the remote solenoid won't cure the problem, although it may help the hot start, depending on what the symptoms are then. if I understand correctly, the problem with a "hot" solenoid is that it doesn't engage at all, resulting in a "dead" battery "click" sound and the starter not turning over at all. if your starter is dragging but turning over, then I think the problem is elsewhere in the starter or the cable connections.

ok, I was thinking along the same lines. I am going to replace the old solenoid, upgrade my cables and add the remote solenoid all at the same time. Hopefully this will remedy my issues.

you are right it tries to engage while hot but drags creating a very loud sound.

I began to notice the issue while it was hot. It would crank very slow and sometimes kick back. After a week or so of this I began seeing similar symptoms during cold start too. I'm also going to take a look at timing as I have recently adjusted it.

The loud sound and attempt to turn over really makes me think it is trying to turn it over but not getting enough juice to do so.

If it is heat that is damaging the starters would it be the solenoid that is being damaged by the heat?

[bmfm64]

During my hot start issues I would get nothing. No clicking, no dragging of the starter just nothing. If you are getting kick back and slow starter I would say maybe hydro lock or something along those lines. Or possibly timing but the starter is not where I would start looking for issues.
Posted via Mobile Device

[bmfm64]

During my hit start issues I would get nothing. No clicking, no dragging of the starter just nothing. If you are getting kick back and slow starter I would say maybe hydro lock or something along those lines. Or possibly timing but the starter is not where I would start looking for issues.
Posted via Mobile Device

[fixit-p]

Originally Posted by davebloomer

ok, I was thinking along the same lines. I am going to replace the old solenoid, upgrade my cables and add the remote solenoid all at the same time. Hopefully this will remedy my issues.

you are right it tries to engage while hot but drags creating a very loud sound.

I began to notice the issue while it was hot. It would crank very slow and sometimes kick back. After a week or so of this I began seeing similar symptoms during cold start too. I'm also going to take a look at timing as I have recently adjusted it.

The loud sound and attempt to turn over really makes me think it is trying to turn it over but not getting enough juice to do so.

If it is heat that is damaging the starters would it be the solenoid that is being damaged by the heat?

You should probably start your own thread and avoid the Hijack, none of what you describe would benefit from a remote solenoid. Check your timing and battery cables (voltage drop test).

[fleetsidelarry]

Originally Posted by fleetsidelarry

if your starter is "sounding bad" when cold, then the remote solenoid won't cure the problem, although it may help the hot start, depending on what the symptoms are then. if I understand correctly, the problem with a "hot" solenoid is that it doesn't engage at all, resulting in a "dead" battery "click" sound and the starter not turning over at all. if your starter is dragging but turning over, then I think the problem is elsewhere in the starter or the cable connections.

and just to close the loop, the underlined part above is incorrect, there shouldn't be any clicking sound. clicking would indicate that the relay (solenoid) is switching, and if it's switching, then a remote won't help.

[FreakyMalo]

I found a much simpler solution to the F*rd solenoid. Replace your battery cables with welding cable. The type for a stick welder. It's heavy gauge and designed to carry a lot of amps.
I had the hot start issue; mine would slowly drag the starter and sometimes a jump would help but most times not. I redid the cables and had zero issues for 5+ years after that and the temps go 100+ here in the summer. I soldered my terminals on with a propane torch and rosin-core solder for a more corrosion-resistant connection. Be sure and use rosin-core because it's acid free. Find it at any Radio Shack.

The difference is in the filaments. Automotive battery cables have a few dozen fairly heavy filaments inside while the welding cable has a bazillion little tiny ones. When the electrons travel down the cable, they travel along the surface of the wires not through the middle. Smaller filaments provide more surface area, allowing more amperage to pass through.

The best part: you won't have all that extra stuff bolted to your firewall.

[fixit-p]

Originally Posted by FreakyMalo

I found a much simpler solution to the F*rd solenoid. Replace your battery cables with welding cable. The type for a stick welder. It's heavy gauge and designed to carry a lot of amps.
I had the hot start issue; mine would slowly drag the starter and sometimes a jump would help but most times not. I redid the cables and had zero issues for 5+ years after that and the temps go 100+ here in the summer. I soldered my terminals on with a propane torch and rosin-core solder for a more corrosion-resistant connection. Be sure and use rosin-core because it's acid free. Find it at any Radio Shack.

The difference is in the filaments. Automotive battery cables have a few dozen fairly heavy filaments inside while the welding cable has a bazillion little tiny ones. When the electrons travel down the cable, they travel along the surface of the wires not through the middle. Smaller filaments provide more surface area, allowing more amperage to pass through.

The best part: you won't have all that extra stuff bolted to your firewall.

The Ford solenoid wont fix a slow cranking condition the problem here is poor connection/cables.

What the Ford solenoid will fix (no click/no solenoid engagement) cannot be fixed by upgrading cables, those are 2 separate circuits.

[RichardJ]

I am not a fan of using a ford relay in that manor.

The purpose of adding a relay is to eliminate the resistance from running the wire up into the cab and back out to roughly the same place it started.
The wire going into the firewall can have corrosion on the crimp at the terminal. Corrosion on the terminal it contacts in the plug and corrosion on that terminal/wire crimp. A little resistance may be added at eack of the ignition switch terminals as well as the switch contacts themselves. Add a Neutral Safety Switch and you still have the connectors coming back out through the firewall.

I hope my drawings are good enough to show what I am talking about.

The first drawing shows the path for solenoid current. There are two coil windings inside the solenoid. The first one is the one we are concerned with and it draws about 12 Amps. That 12 Amps flows through the ignition switch. That coil is the one that pulls the solenoid in and gives the Click.
The other coil draws about 40 amps and that is what keeps the gear out against the flywheel. It draws all of its current from the battery cable and not through the ignition switch.

I don't know how much current a Ford relay draws, but I suspect it is only slightly less than the GM 12 Amps. The advantage of the Ford relay in a Ford or added to your truck is that it isn't exposed to the heat when mounted out on the fender.

You have to see that energizing TWO high current solenoids is not to your batteries advantage.
It is also not to your advantage to cut into the battery wire and add more resistance with extra connectors and extra switch contacts.

A Bosch relay only draws about 40 milliAmps, but the relay contacts can carry an easy 30 Amps from the battery wire to the solenoid S terminal.

Smaller, easier to install and does a better job, especially in the energizing circuit.

That 6 gauge wire is about two miles beyond overkill. That would carry an easy 200 Amps @ 12 volts. The typical GM purple starter wire is 12-14 gauge depending on the distance.

[VetteVet]

Here's another diagram showing Richards idea. No split battery cable, use the "S" wire from the ignition to activate the relay, ground the relay on terminal 85 and send a full 12 volts through the relay via 30 and 87 to the starter solenoid and you're done.

[FreakyMalo]

Should have added that I had already rewired the car with an aftermarket harness (with soldered terminals) when I had the slow cranking issue and tried a relay similar to VetteVet's diagram, only I tapped power from the batt. terminal on the solenoid. It didn't help but seeing fixit-p's last post now I know why; my upgraded start wire was enough to trigger the solenoid but the battery cable couldn't deliver the amperage. So it's two separate but related issues.

[Budman56]

Originally Posted by richardj

i am not a fan of using a ford relay in that manor.

The purpose of adding a relay is to eliminate the resistance from running the wire up into the cab and back out to roughly the same place it started.
The wire going into the firewall can have corrosion on the crimp at the terminal. Corrosion on the terminal it contacts in the plug and corrosion on that terminal/wire crimp. A little resistance may be added at eack of the ignition switch terminals as well as the switch contacts themselves. Add a neutral safety switch and you still have the connectors coming back out through the firewall.

I hope my drawings are good enough to show what i am talking about.

The first drawing shows the path for solenoid current. There are two coil windings inside the solenoid. The first one is the one we are concerned with and it draws about 12 amps. That 12 amps flows through the ignition switch. That coil is the one that pulls the solenoid in and gives the click.
The other coil draws about 40 amps and that is what keeps the gear out against the flywheel. It draws all of its current from the battery cable and not through the ignition switch.

I don't know how much current a ford relay draws, but i suspect it is only slightly less than the gm 12 amps. The advantage of the ford relay in a ford or added to your truck is that it isn't exposed to the heat when mounted out on the fender.

You have to see that energizing two high current solenoids is not to your batteries advantage.
It is also not to your advantage to cut into the battery wire and add more resistance with extra connectors and extra switch contacts.

A bosch relay only draws about 40 milliamps, but the relay contacts can carry an easy 30 amps from the battery wire to the solenoid s terminal.

Smaller, easier to install and does a better job, especially in the energizing circuit.

That 6 gauge wire is about two miles beyond overkill. That would carry an easy 200 amps @ 12 volts. The typical gm purple starter wire is 12-14 gauge depending on the distance.

So is it my understanding that this will fix the heat soaked starting issue? Boy if that is the case I wish when I asked this question, my thread http://67-72chevytrucks.com/vboard/s...d.php?t=534612, I would have got this answer instead of the ford solenoid fix. I have already installed the ford solenoid into my truK and got a bunch of S**T from my freinds for doing so. But it was the only fix that was offered. I wish some one would put this into the faq index so that when people like me come here to find answers we can have a choice of which way we want to fix our trucks.

HERE IS ANOTHER THREAD DICUSSING THE SAME ISSUE WITH INSTALLING THE FORD SOLENOID http://67-72chevytrucks.com/vboard/s...d.php?t=534853 HERE THERE IS ANOTHER GUY THAT SAYS INSTALLING HEAVY WELDING CABLE WILL UP THE RESISTANCE AND THUS ALSO FIX THE HEAT SOAKED STARTING PROBLEM.

[fixit-p]

Budman don't get too down on your mod just yet, while it is true what the mod addresses is current delivery to the S terminal which can be achieved with just a 30 amp ISO relay. There are two ways to wire in a magnetic switch (that's what Delco calls them on their larger starters) the best way IMO is the way you did it.



The added advantage with the way you installed it is that there are no hot wires at the starter near all that heat, that is what I personally like most about the magnetic switch mod.

The other way going around in regards to wiring in the magnetic switch is to use the magnetic switch only to power the S terminal and not interrupt battery supply to the starter.



That way makes no sense to me and you would absolutely be better off using the ISO relay instead of a magnetic switch. I tested a Cole Hersey solenoid and it draws 6 amps which is much higher than the ISO relay but there are other advantages other than just supplying power to the S terminal.

[VetteVet]

There's advantages and disadvantages to each system.
The Ford solenoid is very reliable and it makes for a nice terminal
point on the battery side for other accessories. It also separates the battery cable so that the starter side is hot only while starting. A major point when the cable gets against a hot header pipe and burns off the insulation. That alone might save your truck harness. They also save on current running through the key switch letting it live longer. If you've ever had to crank the engine longer than normal and felt the key switch wiring then you know what I mean. The relay also does have this advantage but it won't stand the current as well as the ford solenoid.

The relay can be put closer to the starter solenoid and is easier to wire in as stated.
it draws less current from the key switch than the ford solenoid. It is also fairly reliable but the cost goes up when the relay amperage capacity increases.

The biggest disadvantage for the ford solenoid is that it is easy to over come theft prevention systems. A hot jumper to the ignition coil or HEI dizzy and a screwdriver to jump the solenoid and vrooom the engines running and the thief is gone in less than 30 seconds.
I guess it depends on what you like.

[fleetsidelarry]

fixit-p and VetteVet, great summaries. clear, consise and informative. and this has been a good, informative thread.

[VetteVet]

Here's a few extras for the viewers.

Starter solenoid in action



Inside the solenoid-The contact plate at the rear moves to the right and connects the large post battery cable with the starter windings, while the solenoid electromagnet moves the bendix lever to the left to engage the flywheel.



Typical starter wiring.



A view of the inside of the starter.



Here;s a nice write-up on bench testing a starter.
....http://www.misterfixit.com/starttst.htm