383 240z Posted July 24, 2002 Share Posted July 24, 2002 I'm putting a ford starter solinoid on my chevy powered 2nd gen RX-7 (or is it8?) does anybody have the scematic on how to wire this? I rember seeing one from MAD RIVER in one of my HOT ROD type magizine but of course now I can't find it!!! Keith Quote Link to comment Share on other sites More sharing options...
Mike C Posted July 24, 2002 Share Posted July 24, 2002 The battery connects to the Ford solenoid. The switched side of the Ford solenoid connects to the GM starter with a batt cable. The start post of the GM starter is hardwired to the big terminal on the GM starter with a 10 ga wire or so. Then connect your OEM start wire to the start post of the Ford solenoid. You aren's really bypassing the GM solenoid, just making sure it gets full batt voltage when you turn the key. Quote Link to comment Share on other sites More sharing options...
383 240z Posted July 24, 2002 Author Share Posted July 24, 2002 Does this help with a heat soak/hot start problem? I don't like clearance between the solinoid (GM) and the header. Keith Quote Link to comment Share on other sites More sharing options...
Dave Posted July 24, 2002 Share Posted July 24, 2002 Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 24, 2002 Share Posted July 24, 2002 It helps to deliver maximum voltage, but does not change the heat to the starter. It'll start, but I just did mine and it still doesn't spin as free as it does when its cold which I was hoping for. There is a starter heat blanket that might help, I'd stay away from header wrap as you'll rust the headers out. I hooked mine up by removing the wires to the chevy starter put the big terminal on one of the large post on the ford solenoid, put the small wire to the 's' terminal, run a additional lug to lug starter cable down to the starter. Make up a small pig tail with a big loop end and small loop end. Hook the big loop of your made up pigtail onto the big post on the chevy starter and run the other end of the pigtail to the 's' terminal on the chevy starter. If your running a HEI, your done. If you run a point ignition you'll need to run a wire from the 'I' terminal on the ford solenoid to the coil to bypass the ballast resister during cranking. Thats about it. This whole diagram is in the archives, theres a link to a chevelle site I believe it is that I was able to find, sorry I don't have it handy. Don't buy the summit kit, save 10.00 bucks and get the parts at napa or pep dudes or whatever, I ordered a solenoid for a 73 ford truck with a 390 and got a 42" lug to lug cable for 15.00 total, summit wants 25.00 for basically the same thing with the little pigtail. *shrug* Good luck with it, regards, Lone Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 24, 2002 Share Posted July 24, 2002 Thought this my be something to think about here. I recently replaced my old (Non-solenoid starter that used the Ford remote solenoid) starter with a new mini high torque starter that has the solenoid attached to the starter. I wired it just exactly like the diagram above and incured a problem. The starter would stay engaged into the flywheel for about 2 to 3 seconds after the engine started (made a hell of a lot of noise). I found out that the starter motor was being spun by the flywheel ring gear, creating a voltage (just like a DC motor being spun by an outside power source) that then pasted through the jumper (12 supply to solenoid jumper on the starter) which then kept it pulled in. Eventually the ring gear kicks the starter gear out and the starter stops. To fix this I had to remove the start wire jumper on the starter, and replace it with a wire that comes from the "S" on the Ford solenoid. This way the 12VDC is cut immediately when you release the start switch and cannot be supplied by the spinning motor. It worked, and now I'm not spinning the starter with the flywheel anymore. It's similar to the electric radiator fan arrangement. When you turn off the radiator fans, they will generate 12VDC back into your electrical system at first and then slowly dropping off the voltage generated until the fans come to a stop. Quote Link to comment Share on other sites More sharing options...
Dave Posted July 24, 2002 Share Posted July 24, 2002 BLKMGK had a problem with his GM mini starter doing I think the same thing. I wonder if a large diode in the jumper to the GM S connection would also solve this? Looking at the wiring diagram it should do the same at the ford solenoid that it does at the stock one. But then again maybe not because its not connected to the battery lead. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 24, 2002 Share Posted July 24, 2002 I was told by a guy to knows this business that a diode would indeed do the trick too. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 24, 2002 Share Posted July 24, 2002 The only thing that comes to mind with a diode is that in order for it to allow the solenoid to operate correctly, then it must be biased the same way that would allow the solenoid to still be pulled in after the motor is running. If the voltage reverses itself while the motor was running then I would think this would push the solenoid open, but this is not the case. So biasing it to prevent the solenoid from staying engage would also prevent the solenoid from starting the engine in the first place??? Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 24, 2002 Share Posted July 24, 2002 Terry, if I understand the placement of the diode as described above correctly, I agree it would not help for the reason you state. Besides, diodes don't like to take alot of reverse current if it could be connected in some fashion to block the back-emf anyway. I only use them to block low current sneak circuits. Quote Link to comment Share on other sites More sharing options...
Mike C Posted July 24, 2002 Share Posted July 24, 2002 Now that you have the gear reduction mini starter, you should be able to eliminated the external solenoid. I had heat soak probs on both my trucks and replaced the crappy GM starters with CVR Nippondenso gear reduction starters. No problem now no matter how hot they get. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted July 24, 2002 Share Posted July 24, 2002 I am not sure what this fix is trying to do. If you guys tell me it makes the starter work better when hot, then I will take your word for it. But electrically it doesn't make any sense. Especially as wired above. The solenoid does two things. It pushes the starter gear into the flywheel and it connects the battery cable to the starter. The same movement that enages the gears forces a copper disk across the terminals on the back of the solenoid. Thus when cranking the terminal connected to the battery cable is connected directly to the starter lug (the terminal at the bottom of the solenoid) and the I terminal going to the ignition. What I think you guys want to do is connect the S terminal on the GM solenoid to the ignition switch (or the the S terminal on the Ford solenoid as someone pointed out earlier), but then connect the big cable from the ford solenoid directly to the starter lug. Don't connect anything to the GM solenoid's top lug or "I" terminal. This is essentially what Lone said to do by jumpering out the top and bottom lug on the GM solenoid. Even if you do this, all you are bypassing is the switch in the back of the solenoid. I don't see how heat could affect this much. (But then I have been wrong before.) Now I do know from personal experience that the copper disk connecting the solenoid lugs can get very corroded and burnt. When this happens, the solenoid will click as the gears are engaged, but the starter won't crank due to the bad connection. (Disassembling the solenoid and cleaning the contacts with a file will usually fix this. Or alternately shorting out the lugs with a screwdriver.) So maybe connecting the Ford solenoid like Lone or I said may give the starter just enough extra current to overcome the heat soak? But I would think that as long as the solenoid disk and lugs are clean that the voltage drop through the solenoid will be minor. Quote Link to comment Share on other sites More sharing options...
Mike C Posted July 24, 2002 Share Posted July 24, 2002 What you are really doing is bypassing the ignition switch wiring. That way you don't have the current/voltage loss since you are "switching" the GM solenoid with a 1" long 10ga wire. Since the current demands of the GM starter are higher when it is hot, the full 12v makes a BIG difference. The Ford solenoid just cuts current from the batt cable to the GM solenoid when deactivated, and supplies batt power when activated. Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 24, 2002 Share Posted July 24, 2002 Jim / Lone - I agree with your assessment - a real benefit of doing this would be had if you jumpered across the large lugs on the solenoid. A length of copper bar stock with a good sized cross section, drilled for the two lugs and bent just so would seem to really help. I also agree with Mike that if the S wire to the GM starter is too long, and maybe not in good condition, and/or the connection to the starter isn't good, that the solenoid might not pull in hard enough to get the copper disk that Jim is referring to push against the solenoid terminals in the GM solenoid hard enough to overcome all the corrosion, pitting, etc. that these parts develop over time. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted July 24, 2002 Share Posted July 24, 2002 I don't think the ignition switch is issue. Look at blueovalz's comment. Connect the S terminal on the GM solenoid to the S terminal on the Ford solenoid and it is all good. It is probably the voltage drop across the two big lugs on the GM solenoid. Thus don't use the wiring diagram above. Somehow get the big wire off the ford solenoid to hook straight to the starter lug (or jumper across the two big lugs on the GM unit) and connect the S wire on the GM to the S lug on the Ford. BTW, a DC motor and a DC generator are one and the same thing. Just a difference in prime power direction. Thus what blueovalz says is plausible. However I would have thought the overrunning clutch in the starter gear would have prevented the generator action. Maybe that is why some guys have seen the problem where others haven't, better clutches. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 24, 2002 Share Posted July 24, 2002 One last comment on this subject. I had thought about tying the 12vdc directly from the remote solenoid to the GM start lug, but was concerned about the timing of the gear spinning and its relationship to this gear being pushed into the flywheel. My reasoning was that the solenoid should be driving the gear into the flywheel before the 12vdc torque is applied to this gear via the motor winding. I was concerned that if the 12vdc was applied to the motor at exactly the same time that the solenoid was being energized, then the gear would be spinning before it reached the ring gear, causing grinding or worn teeth. Thus I returned the 12vdc back to the proper lug on the GM solenoid, thus allowing the Ford remote solenoid "start" signal to energize the GM solenoid, and giving the starter gear time to move forward into the ring gear prior to the 12vdc being applied to the motor winding itself (via the contacts at the end of the solenoid travel path). Quote Link to comment Share on other sites More sharing options...
383 240z Posted July 25, 2002 Author Share Posted July 25, 2002 WOW this has gotten more complicated than I had expected! I just wanted a convenient place to hook up my pushbutton starter for setting valve lash. The heat issue was just an after thought. This is for my RX-7 hybrid the factory stater was mounted drive side I thought a ford solinoid would be a good junction for the extentions needed to mate the chevy starter to the MAZDA wiring(the jap version of LUCAS I'm sure) Keith Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 25, 2002 Share Posted July 25, 2002 "So maybe connecting the Ford solenoid like Lone or I said may give the starter just enough extra current to overcome the heat soak?" Exactly. It gives it just enough extra to start thats my understanding. This isn't a phenomena common just to this application, I've seen other chevy's with headers experience the same thing. I didn't help things on my application by Y'ing under the starter and running 3" from there back in mine. If I were to do it again, I'd probably route to the other way, but theres less room with the T56 clutch slave and such on that side. *shrug* M anifolds that were more of a front dump pointing down might help a bit, although they just don't normally make manifolds like that. Perhaps turning rear dump manifolds around and trying to route outside of the starter might help, but the chevy is back there so far there just isn't alot of room to route 2.5" pipes by it to easily. I'm of the opinion that your exhaust routing obviously is the key to how badly the problem will be. I have another solution, but it involves my motor in another chassis non Z and thats becoming more of a real possiblity considering my situation. Good luck with it though. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 25, 2002 Share Posted July 25, 2002 If thats all you want it for, then it works great for that. I can now turn it over easily with a push button under the hood (or a screwdriver shorted from the big solenoid battery lug to the 's' terminal, old Ford habit for me... ). Regards, Lone Quote Link to comment Share on other sites More sharing options...
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