I was curious as to whether the "I" terminal on the starter solenoid is full 12v with key in on,and run position. if so, could I run the 12v feed for my MSD box to this terminal?
I terminal? Which one is that? http://www.v8buick.com/attachment.php?attachmentid=37439&d=1101398444 12 volt feed to the MSD. Do you mean the turn on lead? (small red wire) You can use the original + wire to the coil for the turn on wire. The big red and black wires should go directly to the battery.
thanks, I guess I made a mistake they were marked "R" and "S" like in the pic yes I meant the red turn on lead. the original HEI bat feed wire was long gone before I got the car
It's an 82 Regal right? There are plenty of 12 volt ignition feeds in the fuse box you can use. Just run a wire from the fuse box. The R terminal is energized only when the engine is cranking.
yes, it is. I just wanted to make certain I used the right terminal in the fuse box,as the markings on the fuse box are very faded,and hard to read.
Use a multimeter, or a test light. You want battery voltage when the key is in the run and crank positions.
that's what I will do, I think I have a voltmeter I can use, thanks again was just wanting to verify that I had 12v to my box I know there's 3 "IGN" terminals, but I didn't know if they all were hot with key in run,and cranking positions, I'll check that out
On solenoids, GM is the "R" terminal, Ford is the "I" terminal, same function. I see a response to this topic by IgnitionMan on BuickThunder. Regards, Milton
What if there's a fuse there though? How do you utilize that terminal then? Or are you saying there will be a free spade you can use?
What some guys do is put a crimp on spade connector, and shove it in between the fuse and fuse holder on one end. The correct way to do it is to just trace the wire from the + side of the coil, back through the harness to the firewall. Then remove the wire from the firewall connector and replace it with a plain 14 ga. wire. It's not that hard to do it the right way.
I see. More than one way to skin a cat. As I understand you now, from the R terminal, I must trace back to the point at which the resistor wire is integrated in. Trace this resistor wire to the fire wall and remove it from the pin at the junction block and replace with a regular piece of 14 gauge auto wire. Take that new piece of auto wire and run it to + terminal of coil. The only question remaining then is what to do with the wire that is currently on + terminal of coil? That's the only way juice is getting to the R terminal on the starter right? Or did I just fall down again? :laugh:
No, voltage flows the other way, from the "R" terminal to the coil. That bypasses the resistance wire, but it only does so during cranking. Once the engine starts, and you let go of the key, and you are in run, nothing flows from the "R" terminal. It's just a bypass.
Ok, so technically then, if I run a wire from the panel to the coil that has 12v at both crank and run position, why do I need to have the R terminal wire connected to the starter at all anymore if all it is used for is to supply 12v at crank to the coil? The new wire will take care of all that right?
Ken, Use of the R terminal on the solenoid is only required if you have points, and a stock wiring harness. All other applications will not use that terminal. What that wire does is by-pass the build in factory resistor wire, to aid in hot re-starts. I don't know what type of ignition your hooking up.. some of the "points replacement kits" that fit under the cap, required a resistor on the coil, so be careful about eliminating it. Most of those kits were designed like this, to be a "drop in" deal, with no wiring required, other than the leads from the distrib to the coil. Aftermarket CD boxes are a different deal. As is adding in an HEI, and there are a couple of things to consider. There are only a couple feeds that stay hot in with the ignition switch in the crank position, that's why most guys find the original coil positive wire, and get that terminal out of the harness plug, and replace that wire with a solid heavy gauge wire to run an HEI. In an MSD setup, or other similar aftermarket CD ignition boxes, the original feed for the points is used for the key on signal to the box (light gauge red) and the heavy guage red goes to direct, hot at all times power. This can come from the battery, the back of the Alternator or the batter cable lug on the starter. You can shorten the original coil + lead in this application, thereby eliminating the majority of the reistance wire, and then hook your key on signal voltage to the box to this wire. The box is looking for 8 or more volts, and there is no current flow in this circuit, so the short length of resistor wire that is left is of no concern. Hope that helps. JW
In reality, the R terminal does not go cold when the ignition switch goes to run, it goes to the resisted voltage, fed by the coil end of the wire connected to the plus side of the coil. The actual R terminal is disconnected from the full 12 volt voltage at the solenoid, when in ignition switch run position, though. Regards, Milton
Jim, Thanks. It does help somewhat. I am using a Pertronix kit with a flamethrower coil. No more points. I have a black and red wire that come out of the distributor now which I guess I hook to the coil - and +. My goal here I think is to eliminate the resisted wire altogether and run as you say a full 12v from the firewall plug to the coil which will provide 12v constant at crank and run. I can then not even bother reconnecting the existing old positive wire (the wire that goes to the R terminal and also T's into the resisted wire)to the coil because I am essentially eliminating it at that point by bypassing it anyway. Is what I have said on the mark?
