Wierd electrical events when starting

jamyers

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Here's what I've got: '62 Ranchero, with a Duraspark/HEI ignition and the original 2-pole starter relay ("S" and "I" wires coming off the relay). I fed the ignition by replacing all but 1" of the original resistor wire behind the dash with regular wire, the only bit of resistor wire left is right at the firewall plug.

I've got two problems that I'm trying to figure out...

1. Occasionally, (like once a week or so) my Ranchero's starter relay will just click when I hit the key to start. Usually the second try it'll spin over and start just fine like nothing's wrong, sometimes it'll do it twice (just click). Battery is fine, I've cleaned all the cables and contacts. Replaced the starter relay a couple of months ago, but no difference.

2. When it does just go 'click', if you don't let off the key immediately, you get a lot of current coming back through the ignition feed wire (from the switch to the ignition coil). I know this because it burned the insulation off of the tiny bit of original resistor wire by the firewall plug (lots of smoke that morning) Since then, I've disconnected the wire from the "I" terminal on the starter relay, thinking that it was somehow back-feeding.

Any ideas what to look at next, and why it'd try to burn up wires?
 
Think about it...

Your ignition switch provides 12v to the coil. Your solenoid provides 12v to the starter.

The I post on the solenoid is connected to the starter terminal.

When you engage the solenoid, it is **supposed** to provide a 12v boost to the coil to aid in starting.

However, if the solenoid is not working properly or something else is wrong, causing the heavy 12v lead from the battery to the solenoid to not provide juice to the starter, the starter is going to try to pull it's current through the I terminal.

That would mean WAY more current than that little 18g wire can possible handle. That will melt insulation....

If you have the resistor wire in place, it will limit the current that this can pull, and henceforth not be a problem. Now that you do not have that in place, it's off the the races w/ the current draw and smoking the insulation on your wires.

So, one - disconnect the I terminal. With 12v constant to your coil - you don't need it.

two - figure out why your starter isnt getting it's 12v. I suspect the solenoid.
 
I understand that the starter relay is supposed to feed full 12v to the ignition when spinning the starter, but how would the starter try and draw current through that "I" terminal? At any rate, I've got it disconnected - so hopefully won't try and fry any more wires.

But why the clicking?

I think I may have to pull the starter and triple-check it's contacts/bearings/bushings/drive.
 
Bort62":1zeefvll said:
...

two - figure out why your starter isnt getting it's 12v. I suspect the solenoid.

I do too.

The heavy contacts inside the solenoid are not making good connection but the contacts enabling the "I" terminal ARE making contact. As Bort pointed out, the starter is attempting to draw through the small wire via the "I" terminal :evil:
Joe
 
OK, it finally makes sense to me how that'd happen.

Easy enough to change out the relay...I'll be sure to get a good old "Made in USA" one. Any part numbers for a really heavy-duty (aka last forever) version?
 
8) i suspect that you have a problem with your ignition switch. i had a similar problem with my 66 falcon and when i went to replace my ignition switch the old one fell apart.
 
JAMYER


.....THE SOLENOID MUST BE GROUNDED. CLEAN AND MAKE SURE YOU TIGHTEN ALL NUTS AND THE SCREWS TO THE BODY. DO THIS FIRST AND SAVE YOUR MONEY.

LIVE IN GRACE

LEROY POLL
 
If the solenoid is clicking then the ign switch is working... but the solenoid itsn't getting enough power to turn the starter.... os it just chatters thats the contacts making and braking contact. is the block grounded? is the sonenoid grounded? are you sure the wires are clean at the post? thats where most of this kind of prob comes from or a bad battery. the battery post should be shiney, the inside part of the cable clamp should be shiney as well so there is good conection....
Tim
 
When I said I suspected the solenoid, I didn't necessarily mean that it was itself bad.

Improperly grounded etc. would all qualify as well. However, if it is clicking, I doubt it is a ground problem w/ the solenoid itself.
 
All cable connections are and have been clean and tight, including the mounting screws (grounds) for the relay, as well as the block-to-battery and extra block-to-chassis ground cables. (After owning an MGB, I've gotten into the habit of obsessing about clean/tight connectors)

I've had the ignition switch out recently, gave it a going-over and it looks good.

I picked up a good-looking Standard brand made-in-USA relay this morning, and I'm planning on yanking the starter out tomorrow and giving it a once-over just for good measure.
 
Starter Relay was bad, go figure. I looked at receipts, and it's only 5 months old - but made in China, so I guess that's what I deserve.

The starter is fine, it checked out 100%. Not too surprising, since I rarely have to crank the engine more than a second or two.
 
Apparently, overtorquing the terminal nuts can cause some to fail; it stresses the internal wire conection to rear of the threaded stud.

Like Joe, I dissect them - if only for the recyclable copper!
 
I opened it up to see what was going on, didn't find anything obvious. I think the coil is just so cheaply made that it'd hang up instead of making clean contact.

Speaking of overtightening the nuts, I love how a standard open-end wrench is too thick to get on the thin inner nuts to back it up when you tighten. :evil:
 
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