1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

electrical help ??????????

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Old 11-30-05, 03:48 PM
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electrical help ??????????

well i drove my car a little and then all of a sudden it acts like its loosing fire. so i park it at my house. i went out to crank it and my battery was dead. i was fine when i parked it and out of the blue its dead. i also can not get fire to the trailing coil and cant get the tach to work which feeds from the trailing some where. i dont know what the deal is. can anyone help me out, i dont know if i need a regulator or ignitor or alternator or what the prob is. if some one can help me out i would appreciate it thanks robert
Old 12-01-05, 03:56 AM
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need some advice on this badly can some body help????????
Old 12-01-05, 04:16 AM
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The car dying sounds like an alt to me. Make sure the belt isn't broken. It may have a short in it that caused the battery to discharge while sitting. Also check the battery terminals, cables, and ground. Sometilmes when these are bad, the battery can seem dead when it is not. Go ahead and get the battery charged and have both the batt and alt tested to be sure. It is free at most autoparts stores.

If the alt is bad, I would go ahead and pick-up a later model alt that has an internal voltage reg. Does your '79 still have points or has it been upgraded to electronic ignition? The dead tach may be due to a bad ignitor.However, I would fix the alt/charging situation first. The 79/80 cars share the voltmeter with the tach. If the alt is not charging, the tach/voltmeter will work as a voltmeter instead of a tach. Also, the 79/80 do not fire the trailing all the time. This is to keep the fire in the thermal reactor going. The 79/80 normally run the tach off the leading because of this. It may be different if it has been modded to have a 81-85 ignition, though.

Hope this helps some. If you can give more details to the car like if certain things have been modded or if it is still stock, that may help us figure out the problem.

Kent
Old 12-01-05, 08:36 AM
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well the battery is new and as far as i know its hooked up right i think it has somthing to do with the alt and reuglator, the battery will not drain if i take the reg fuse out over night. for the tach it dont do anything at all and i have checked the trialing and it want come on at all???????/ well thanks and if you can help me out more i would appreicate it thanks
Old 12-01-05, 08:42 AM
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test the output on the alternator. make sure its putting out between say, 12 and 14 volts. too much or too little and either the alternator itself has failed or the voltage regulator has given up the ghosts.
Old 12-01-05, 08:45 AM
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So, the igniton is still points then? If removing the fuse fixes the drain, there is probably a short in the alt or reg. Just get it tested and see what's going on. We can then figure out the tach issue. Just for the record, it is a 1979, right (judging by your profile)? If the alt or reg is bad, I would go ahead and upgrade to a later model alt. You have to do a simple wiring change, but that is shown in the archive.

Does the tach show batt voltage when you turn the key on? Does it show batt voltage when running or just shows nothing at all?
Old 12-01-05, 10:54 AM
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sorry i forgot i changed over to a electronic distributor before it went all together. everything on it is new or fixed except the wiring and ingintion stuff. the alt tested good on charging capabiltity but they said it could have a probelm inside that is causing it to drain, and the tach will do nothing at all does not move. well you guys let me know what you think and if i should upgrade what should i do what parts and all. thanks robert
Old 12-01-05, 09:37 PM
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with the upgrade alt what all changes? and will that help out that much? if so what can i do to my ignition to get it right?
Old 12-02-05, 02:33 AM
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If you want to upgrade the alt, how to do it is here:

https://www.rx7club.com/1st-gen-archive-71/electrical-83-alt-79-a-369140/

The '79 was the only 7 to have an external regulator. All the others have internal. The later ones tend to be higher output as well. I would probably just pick up a used one for cheap. The original alts tend to hold up better than the rebuilts you find at AutoZone and such anyway. You can even go to a second gen alt if you want. The 86-88 alts were the same wiring wise as the 1st gens (with the exception of the 79). This would eliminate the external reg and the current alt. Hopefully that will take care of the discharge problem.

For the tach, it sound like something isn't connected. Do the other gauges work? Even if the tach signal wasn't hooked up during the igntion swap, the tach/voltmeter should work as a voltmeter when you turn the car on (when all the warning lights are lit).
Old 12-02-05, 04:15 AM
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thanks, ill look in to that, i have talked to others and they beleive its the regulator, so i will change out the alt and do the jumper thingy. yeah i have a bunch of empty plugs under the hood and dont know what they are. i have tried to find someone in the area to help me but no response. i would like to get the ignition good to while im doing all this wiring. i thougt maybe doing a msd 6a igntion upgrade what you think on that.
Old 12-02-05, 09:50 AM
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There's a diode bridge in the alt (or the external regulator) that keeps current from going back thru the alt from the battery when the engine isn't running (that would be a hell of a deal!). So if that diode is shorted your battery will discharge thru the alt when the car isn't running.
Old 12-02-05, 10:49 AM
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well i checked the regulator and the points in it are worn and its not operating at what the book says, and also the alt is the original so i think im going to upgrade to somthing a bit newer, plus do some work on the ignition that way i wont have any more problems in the future from crap that quits. just not sure what all im going to use for this any suggestions
Old 12-02-05, 12:02 PM
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Well, there are a lot of options on the alt. I believe the 79 has a 50amp alt. The later 1st gens had a 55amp and the GSL-SE has a 60amp. You can also look into a 2nd gen alt. They are rated as follows:

86-88 NA 60amp
86-88 TII 70 amp
89-91 NA or TII 80amp

The 89-91 have a bit different plug on the back than the others. Since you have to adapt the plug anyway, these are as easy as the others. Just depends what you come across. I have the 89/91 on my GSL-SE. I really like it. The voltage is very stable even with lights on, wipers going, heater blower on, etc. I think you will need to use washers instead of the spacer if you use a 13b alt. The GSL-SE already has a 13b, so I was able to just use the spacer.

Since it looks like you want something trouble free, my recomendation is to get a used original RX-7 alt of your choice of year. Most will be in good shape, but if you want peace of mind take it down to a local alt/starter shop and have them go through and rebuild it. This way you will have a quality alt that you know is good and it may be cheaper than getting one from an autoparts store.

For ignition, the MSD is good. It is pretty big and expensive, though. I just happen to be looking to start a group buy on an ignition upgrade I have been working on. This lets you use the leading coil off of a 2nd gen car. Much stronger sparks than stock. Smooths idle, quicker revs, more power, and a couple guys have measured a 2-3 MPG increase.

https://www.rx7club.com/group-buy-center-69/sa-fb-ignition-upgrade-transistor-trick-486305/

/shamless plug

Let me know if you have any questions.

Kent
Old 12-02-05, 02:38 PM
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yeah i talked to you about that earlier, with the 2nd gen coil. now if i go with a lets say 2nd gen Na alternator and then decided to do the igntion upgrade with the 2nd gen coil what all would i have to change with my wiring? just curious, i have loooked around and read about the alt and ign you are takling about but not sure what it intels me to do with the wiring. also where is the best place to find a 2nd gen coil and alt off a 86-88 NA?? thanks for the help guys. im looking to get this done soon so let me know
Old 12-02-05, 03:10 PM
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On the alt end, you just need to do like that thread. The alt has three terminals:
- large post goes to batt +
- 1 terminal to switched ignition source
- 1 terminal to alt warning light

You should be able to just use the factory wiring. As for where to buy, check the 2nd gen for sale section on here or ebay. I bet you could find someone to sell both the alt and coil pack together.

For the ignition, you need to run + connection to the circuit and the coil. 2 wires from the circuit plug into your leading ignitor. 1 wire goes from the circuit to the coil. The circuit needs to also be grounded. The coil gets grounding through its mounts.

The circuits probably won't be done for another month or more. It also depends on if you want to keep the car stock. If so, just get stock replacements. Although, both the 2nd gen igniton and the alt can be installed without damaging/cutting stock parts. You could easily revert back to being completly stock if you ever wanted/needed to.
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