omar_munoz123 Posted July 28, 2009 Share Posted July 28, 2009 Does the negative cable that goes to the battery lead to a bolt on to the transmission...??? Is this how the cable suppossed to lead to...??? Pics Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted July 28, 2009 Author Share Posted July 28, 2009 Lolz "how" I mean is this where the cable is suppossed to lead to...??? Quote Link to comment Share on other sites More sharing options...
jasper Posted July 28, 2009 Share Posted July 28, 2009 That location is acceptable. The cable end at the - terminal probably should be cleaned up. Make sure you have a good ground from battery - to the body. Also a heavy ground strap from the engine to the body. Let me stress......Every connection should be clean and tight. Secure the battery when your done. Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted July 28, 2009 Author Share Posted July 28, 2009 Thanks i was worrying if it should be there or not but now i know Thanks again Quote Link to comment Share on other sites More sharing options...
Jesse OBrien Posted July 28, 2009 Share Posted July 28, 2009 Correct me if I'm wrong, but I believe the factory location is on the starter motor, not the transmission. I'm not sure what (if any) advantage this offers, I'm pretty sure all you're doing is providing a strong ground, and the bolt you're using is the crucial part of that. Here's where I have mine, if it helps at all: Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 28, 2009 Share Posted July 28, 2009 Correct me if I'm wrong, but I believe the factory location is on the starter motor, not the transmission. I'm not sure what (if any) advantage this offers, I'm pretty sure all you're doing is providing a strong ground, and the bolt you're using is the crucial part of that. That's right - the starter bolt is where this generally is connected. The starter is by far the largest current draw in the vehicle, so you want the most direct battery connection to go to it. The location on the trans is okay, but I wouldn't go any farther than that from the starter. I run my ground strap from the same spot on the starter to a good body ground - that way the engine and body are more likely to have the same ground reference level. I don't like having the chassis ground and engine ground voltage moving around with respect to each other. Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted July 28, 2009 Author Share Posted July 28, 2009 Correct me if I'm wrong, but I believe the factory location is on the starter motor, not the transmission. I'm not sure what (if any) advantage this offers, I'm pretty sure all you're doing is providing a strong ground, and the bolt you're using is the crucial part of that. Here's where I have mine, if it helps at all: If that's where the negative cable goes to then where does the positive cable go to...??? Because i looked at mine and saw that the positive cable leads to the spot where your negative goes to... Because for some reason my battery goes down in about a day or two depending how many times i turn it on, so the first thing i checked was the alternator and took it to autozone and they told me that it was good so i don't know why my battery dies out so quick...if anybody can give me info on why you think the battery dies out real quick i would really appreciate it Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted July 28, 2009 Author Share Posted July 28, 2009 Or is that thick red cable your positive cable...??? Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 29, 2009 Administrators Share Posted July 29, 2009 (edited) Thick RED cable is battery positive, goes to the copper bolt/lug on the starter solenoid. Thick BLACK cable goes to the starter "mounting" bolt for a good close ground connection. Transmission bolt does the same thing but the starter mounting bolt is closer, electrically speaking. and is the preferred location for that reason, as described above. Then be sure you have a ground strap/wire from the battery negative post or the starter mount bolt that has the negative battery cable, that goes to the car body. That ensures the car “body” electrics is also properly grounded, (the motor mounts are poor electrical conductors). Edited July 29, 2009 by BRAAP Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted July 29, 2009 Author Share Posted July 29, 2009 Thanks for the help... Now i just have to fix the problem Quote Link to comment Share on other sites More sharing options...
Jesse OBrien Posted July 29, 2009 Share Posted July 29, 2009 That ensures the car “body†electrics is also properly grounded, (the motor mounts are poor electrical conductors). I feel dumb now. I had always known that you were supposed to ground the engine to the chassis, but had never even considered WHY. This makes sense, and the world of engineering seems just a little bit smaller now. Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted July 29, 2009 Share Posted July 29, 2009 get rid of those crappy one size fit all connectors they are a disaster waiting to happen. especially on dark and stormy nights. It is cheap enough to buy new cables with real terminal clamps. On 280zx and z31 Nissan original cables went to the body then to the starter. I don't know why they wouldn't have done that on the Z. Even if not original I would take my negative to a convenient nearby bolt (or weld in a stud) and thence to the starter. YEs going to one of the starter bolts in the conventional way to run the ground strap. Another way tho not as good in my opinion is to buy a ground cable with a 10 ga take off and run a wire from there to one of the many convenient m6 bolts located about the engine compartment. Tired of chasing odd electrical faults - Ask Lucas prince of darkness about insufficient earthings. I take two 10 gage wires from each side of the engine compartment and then back to battery to ensure even grounding all around. Quote Link to comment Share on other sites More sharing options...
Oddjob Posted July 29, 2009 Share Posted July 29, 2009 If you would like to see the industrial, overbuilt, never-have-trouble-again solution, take a look here: http://forums.hybridz.org/showthread.php?t=147928 and scroll down to Post # 15. Fair warning: it's long and a bit theoretical.... Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted July 31, 2009 Share Posted July 31, 2009 good writeup but he fails to take into account that the body and etc take the form of many conductors in parallel which using Ohms law of parallel resistances equates to an imperceptible resistance in that circuit. But if you are having ground problems for say the rear lights then running a conductor back there is going to help immensely but with a lot of welded sections working together you don't have the problem the Brits did in the early days where things were bolted together and developed high resistance at the joints. Quote Link to comment Share on other sites More sharing options...
Oddjob Posted August 12, 2009 Share Posted August 12, 2009 (edited) good writeup but he fails to take into account that the body and etc take the form of many conductors in parallel which using Ohms law of parallel resistances equates to an imperceptible resistance in that circuit. But if you are having ground problems for say the rear lights then running a conductor back there is going to help immensely but with a lot of welded sections working together you don't have the problem the Brits did in the early days where things were bolted together and developed high resistance at the joints. Well, I don’t agree that a ground plane amounts to many parallel resistances. A ground plane is, by definition, one massive ground. Now it is certainly possible to have a number of paths through that single ground, but that will not necessarily result in “an imperceptible resistance”. However, it probably isn’t very helpful to quibble about theory, so I did a bit of empirical observation. The 1971 S30 on which I installed the star grounding system is a full-on restoration/enhancement, which is about 65% done. Everything on the chassis which would come off has been off, has been rebuilt or replaced and has been reattached with new hardware. Any rust found has been repaired by welding, including the replacement of the floor pans. In short, as regards grounding, the physical car is probably pretty average for a restoration, is very much better than an un-restored vehicle, and I am guessing is equal or better than a stock Z when it was new. I disconnected the star grounds at the buss and insulated them, effectively restoring the car’s grounds to “stock”. I then measured the resistance from the negative battery cable, which was attached to the stock location on the starter, to various points around the car. I then restored the star ground buss and re-measured. For this measurement, I borrowed a 3M 965 DSP, which is essentially an industrial digital VOM, costing about $3000. The instrument measures from 0 Ω to 999 MΩ. The chart below shows the results. The first two columns are the observed resistances in each case. The resistance readings for the standard ground and the star ground are directly comparable. The voltage drop calculations for the star ground apply even though the measured resistance is zero ohms in all cases. Note that I did not calculate voltage drop for the stock “ground plane” configuration. None of the voltage drop tools I usually use will do the calculation, because they assume a two-conductor (out and back) circuit of copper or aluminum of the same gauge. The ground plane material is steel (mostly), and of no certain gauge, with many connections. The best that can be concluded is that the ground resistance through the chassis is both higher and very uncertain. That much can be seen directly from the data. Since the measured resistances through the ground plane, in all cases, are higher than zero, I am left to conclude the voltage drop in a chassis ground is rather worse than the star ground. [The chart is in the .pdf at the bottom.] Crib Notes: For those who are not electronics types, a VOM is a volt-ohm meter, a test instrument. When measuring resistance, a low number is either a short or a really good connection and a high number is either an open or a really bad connection. Which is most desirable depends on what you are doing. In the case of a ground, a reading of zero is perfect, and anything less is undesirable. Even with a reading of zero, there will be some resistance and therefore some voltage drop. Even a very good meter does not resolve low resistances very well. Voltage drop at your load is undesirable because all electrical devices are designed to produce their rated results at a particular design voltage. In the case of your Z, that is about 14.5V with the car running. So if you expect your 55w headlight to produce its rated number of lumens, it must see 14.5V. If it is actually getting say, 13V, it will be dimmer than it should be. The interesting thing is that in this example, the bulb is seeing 89% of its design voltage, but will only produce something like 75% of the light it should. This is true for all the load devices in the car. Volt Drop Chart.pdf Edited August 12, 2009 by Oddjob Fix &^@#!! chart Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted August 13, 2009 Author Share Posted August 13, 2009 ok so i changed the negative cable to the starter where its suppossed to be and the battery keeps going down, i know for sure its the alternator and i need to get a new one but a couple of months ago i took it off and took it to autozone just to see if it worked and they told me it did but im gonna go ahead and buy one to see if it solves the problem, if the battery level keeps going down then what could be the problem...??? Quote Link to comment Share on other sites More sharing options...
Oddjob Posted August 14, 2009 Share Posted August 14, 2009 ok so i changed the negative cable to the starter where its suppossed to be and the battery keeps going down, i know for sure its the alternator and i need to get a new one but a couple of months ago i took it off and took it to autozone just to see if it worked and they told me it did but im gonna go ahead and buy one to see if it solves the problem, if the battery level keeps going down then what could be the problem...??? Omar: You don't have enough information yet to know for certain it's the alternator. Do you have a voltmeter on the car? If not, borrow a VOM from someone. Read the meter with the car off, on the battery terminals. It should be 12 to 12.7 volts DC. Now start the car. If the voltage goes up to about 14.5 volts, there is probably nothing wrong with the alternator. Does the car still have a voltage regulator? Also, please confirm this: The battery goes down when you run the car, not overnight when it's parked? Quote Link to comment Share on other sites More sharing options...
rsicard Posted August 14, 2009 Share Posted August 14, 2009 Omar: Get a Volt Ohm Milliameter (VOM) with a 10 ampere function. Disconnect the Postive cable from the battery and insert the VOM, with the leads and switches set for measuring 10 amperes, in Series between the battery positive post and the positive cable end removed. Hopefully the current seen will be less than 0.5 amp or 500 milliamperes (the same thing). If it is above 1.0 amperes on the 10 ampere setting, remove the fuses from the fuse box one at a time to try to establish which accessory is drawing current when it is not supposed to be. If less than 1.0 ampere, then disconnect and reset the VOM to the 500 milliamp scale or lower scale as needed and repeat the process of one at a time locating the circuit that is drawing the current when it is not supposed to be. This is a process of elimination. Once the circuit is located then get the wiring diagram or get back on this thread and give the results. We will try to help you further locate the fault. Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted August 14, 2009 Author Share Posted August 14, 2009 Omar: You don't have enough information yet to know for certain it's the alternator. Do you have a voltmeter on the car? If not, borrow a VOM from someone. Read the meter with the car off, on the battery terminals. It should be 12 to 12.7 volts DC. Now start the car. If the voltage goes up to about 14.5 volts, there is probably nothing wrong with the alternator. Does the car still have a voltage regulator? Also, please confirm this: The battery goes down when you run the car, not overnight when it's parked? Well when i try to start the car it reads on the voltmeter that the battery goes down then as soon as the car starts it goes back up. Also, when i rev the engine too hard it reads on the voltmeter that it goes down and as soon as i let go of the pedal it rises back up. And if i keep on trying to start the car the battery will die out, usually i disconnect the battery just in case the battery does die out when its parked in the backyard but i don't for sure. Quote Link to comment Share on other sites More sharing options...
omar_munoz123 Posted August 14, 2009 Author Share Posted August 14, 2009 Omar: Get a Volt Ohm Milliameter (VOM) with a 10 ampere function. Disconnect the Postive cable from the battery and insert the VOM, with the leads and switches set for measuring 10 amperes, in Series between the battery positive post and the positive cable end removed. Hopefully the current seen will be less than 0.5 amp or 500 milliamperes (the same thing). If it is above 1.0 amperes on the 10 ampere setting, remove the fuses from the fuse box one at a time to try to establish which accessory is drawing current when it is not supposed to be. If less than 1.0 ampere, then disconnect and reset the VOM to the 500 milliamp scale or lower scale as needed and repeat the process of one at a time locating the circuit that is drawing the current when it is not supposed to be. This is a process of elimination. Once the circuit is located then get the wiring diagram or get back on this thread and give the results. We will try to help you further locate the fault. I'm gonna try this out today i'll keep you guys posted thanks! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.