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PostPosted: August 4, 2017, 9:38 am 
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There you go. Electrical problems become way less mysterious when a voltmeter is used to check out everything - including stuff we assume is working fine.

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PostPosted: August 4, 2017, 10:00 am 
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The voltage changes when the wire is not able to supply the requested current. Or the requested current is more than the wire can supply. If you think of it as plumbing with voltage being fluid pressure and current being flow - there is a short piece of narrow pipe in the circuit. It doesn't look like narrow pipe but perhaps it has a very thick wall section so it's a restrictor. Down stream of the restricter there is less pressure, but only if there is a demand for flow. If the demand for flow is stopped the pressure will rise to full pressure.

If the crimps are not put onto a cable with enough pressure, oxides can form on the copper and cause resistance to flow. So for electrics clean connections mean bare metal with no oxide. Oxides form quickly on metals except for gold. The pressure on a crimping tool is supposed to be enough to cause the metal to flow thus getting around oxide and making a gas tight seal so the oxides don't form later.

Using the volt meter you found the place where the pressure drop is occurring. You can't really do that with the ammeter because the flow will be the same all the way around the circuit. The volt meter though will show you how much the pressure changes in each part of the circuit and that lets you know where the power is being dissipated.

Congrats!

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PostPosted: August 4, 2017, 10:21 am 
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horizenjob wrote:
The voltage changes when the wire is not able to supply the requested current. Or the requested current is more than the wire can supply. If you think of it as plumbing with voltage being fluid pressure and current being flow - there is a short piece of narrow pipe in the circuit. It doesn't look like narrow pipe but perhaps it has a very thick wall section so it's a restrictor. Down stream of the restricter there is less pressure, but only if there is a demand for flow. If the demand for flow is stopped the pressure will rise to full pressure.

If the crimps are not put onto a cable with enough pressure, oxides can form on the copper and cause resistance to flow. So for electrics clean connections mean bare metal with no oxide. Oxides form quickly on metals except for gold. The pressure on a crimping tool is supposed to be enough to cause the metal to flow thus getting around oxide and making a gas tight seal so the oxides don't form later.

Using the volt meter you found the place where the pressure drop is occurring. You can't really do that with the ammeter because the flow will be the same all the way around the circuit. The volt meter though will show you how much the pressure changes in each part of the circuit and that lets you know where the power is being dissipated.

Congrats!


I crimped on a new connection so.... it has to be through the switch or the wire is bad or both. I will do some more testing to see what is going on.

now how do I mount the front of this shock cover to hold it (the thing above the wide band gage)? hummmm.... long threaded post? It needs to look clean.
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PostPosted: August 4, 2017, 4:44 pm 
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it has to be through the switch or the wire is bad or both. I will do some more testing to see what is going on.


I was looking at the picture you posted above with the probe on the terminal. Here is a quick test for you. It reads 5V when it is connected to the starter but if you pull that wire off, the voltage jumps to 12V? This means there is a bad connection upstream of where your testing, it could even be the crimp you have the probe on. ( I know you replaced it, just saying in theory ) The wire and the connections upstream are capable of delivering 12V with no load whatsoever. A voltmeter is designed to provide minimum load. When the the selnoid is connected it requires power to actuate it, the circuit is not capable of supplying that power because it has a restriction and thus you no longer see the 12V, you see only 5. That means the selenoid is getting 5/12 of the power going thru the circuit and 7/12 of the power is being lost in the wire, it's connections or the switch.

I guess if you measure the voltage across the 2 switch terminals it will read 7V when you turn it on. You can take a little short piece of wire and short it across the switch terminals and the car will just start right up. If that happens you will have now "hot wired" your first car!

Switches and wires are supposed to conduct, so normally if you connect a voltmeter along their length they will read 0 or close to zero. IN this case there is somewhere in that circuit you should be able to read about 7 volts.

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PostPosted: August 4, 2017, 7:06 pm 
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Replacing the wire from the switch to the starter fixed the issue.... Found the drain too but that will be in the electrical section.

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PostPosted: August 4, 2017, 8:28 pm 
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So what was it, bad crimp?

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PostPosted: August 4, 2017, 10:34 pm 
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Dunno. There was a new connection on both ends... I replaced that one with a whole new wire

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PostPosted: August 7, 2017, 10:51 am 
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The drain ended up being the IG wire that runs to the Alternator. For some reason this was pulling 5amps while the kill switch is on. To solve it i just move the wire to the 12v switched terminal block. Now the car pulls 0.13amps with the kill switch on. I have left it on without a tender to see how long it will take the battery to drain.

The car is still a bit hard to start and I am not quite sure why but I think there needs to be more drives before I can determine what is going on.

Speaking of!!! I got to put a good 60mile canyon drive on her yesterday (after fixing the check engine light... I forgot to plug the alt connector back in when looking for that drain) and it was soooooooo nice. Of course I was stuck behind people for most of the drive but that didn't bother me. It was nice to just cruse and be with the machine. However, I did just putter into the gas station since am not too familiar with how much a half of a tank really means.

Engine temps stayed well below 200° when driving at slow speeds and at high speeds it was around 175°-185° but it was also a cool day outside. Still a "hummmmm" on this one

One thing though, the power cut off a few times, then back on, in the car for no reason. I'm not sure what is going on. At one point I smacked the dash and the power came back on but that might have just been coincidence. Once I got home, I took the dash cover off, pulled on all the wires with the car on and off and nothing. Checked all the grounds in the engine bay and still nothing. Battery connections are good and I even smacked the dash a few times to see if could get it to do it again but no such luck. I'm not sure what to do about that.

After fighting the power issue i moved on to something else... clear engine cover!!!

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PostPosted: August 7, 2017, 4:03 pm 
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that clear engine cover is just a mold. I am now trying to figure out how to make it less boring.... thoughts?

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PostPosted: August 7, 2017, 11:41 pm 
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I have left it on without a tender to see how long it will take the battery to drain.


You can only discharge a battery so many times. Car batteries are not intended for or rated for this, that's what they call a deep cycle battery. So turn it off before you let it sit for days like that. A drain of .13 amps or 130 milliamps will use up about 1 amp/hour for every 8 hours you let it drain. I forget your amp/hour rating but you can pretty much assume that would tell you how long it will take to go dead, but it will damage your battery to do this.

I don't understand your electrical system, is the ECU still doing your alternator voltage regulation? It seems to me the 5A draw would be the alternator field windings. That implies the alternator is running full on all the time. That will cook your battery so that sort of points to why you have had troubles with your battery. It is possible for them to explode, but your battery just uses the damp fiberglass mat so not very much would happen. It's bad news for the old liquid filled ones because they launch acid everywhere.

Sorry I don't have more particular advice, good luck.

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PostPosted: August 15, 2017, 9:03 am 
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Same deal Saturday when I tired to drive the car. She wouldn't power up and lost engine power (not electrical power) like a misfire at one point on the highway but came back on as I was pulling off the shoulder. However I think I found my random off, connection and start issue.

Yesterday I decided to do the same procedure again with starting her up, pulling on wires etc. First the car didn't want to start again and when she did she immediately died. Started her up a few more times and got her running. As I was pulling on wires i noticed that the wire from the kill switch (4pole) to the 50amp fuse switch was warmer then I liked so I decided to replace that with a larger wire. Then I power her back up and nothing. Considering how this is one of those pull to reset fuses (yeah i am getting rid of that for a push button), I removed the wire, reconnected and still noting. So I pulled out the old trusty multi-meter and started measuring stuff.

With the switch on, there was 12v to the two main poles and 12v to one of the smaller poles. However the other smaller pole going to the fuse did not have 12v. I did an continuity test just for the hell of it and with the switch off there was no continuity from the main to the all of the poles and with the switch on there was 0ohms to all but the issue pole which was reading 700ohms. So as a test I moved the fused wire to the working pole and boom she started up really fast. I don't think the starter even cranked once. She has not done that in a long time.

So the switch is bad but the good thing is that I can still use it since only the one pole is bad. If I turn it off everything still dies.

I wont know if this is is causing all of the issues until i can drive her (raining like crazy out here for 3 weeks!) but i will keep you guys posted.

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PostPosted: August 15, 2017, 9:38 am 
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Once again, a multimeter makes all the religious-like mystery vanish and the Truth presents itself!

Regarding the breaker/switch - is it intended to be used as a switch on a regular basis? I didn't think they were intended for 100s of uses. Either way, must feel good to have found the problem!

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PostPosted: August 15, 2017, 10:10 am 
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No its not to be used for on and off, I have a separate switch with that but with the drain issue it was being used frequently.

Hopefully this is the issue... or at least one of them.


Still looking for some creative ways to mount these guys
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PostPosted: August 21, 2017, 3:32 pm 
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I was able to put about 100miles on the car Sunday with out any cutting out or other issues. The scoop kept the air temps to around 109-115°. Not sure if it helped since I left it on the whole time but it was about 90° outside. The engine temps also never went above 195° so that is good.

The CEL did come on at mile 90 but I cannot tell what it is from in the datalog since its showing on but no error code. I will need to run the car some more and see if it comes on again.

I have data logs too in case someone is curious about that....

The datalog shows my car doing 150mph at some point which isn't remotely true (i wish) so i am not sure how far off that is and when it becomes off.

I also did an infusion on the engine cover Saturday but that came out like crap. I borrowed some resin which i think was just too think. A moot point though since once i put it on the car, i didn't like the way it look any way. I will probably just leave the engine exposed.

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PostPosted: August 28, 2017, 9:56 am 
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Damn this car is fun to drive!!!! Although, even after aligning her again, the steering wheel is still cocked to one side a bit instead of being straight. I'm not quite sure how to fix this. Maybe center it and the turn it slightly to the left so that when it is aligned she will will be straight? Hahahahaha

I am trying to get all of the mounts on the car before she heads to powder coating in the winter. I figured I could swing the mount in towards the chassis but then the wing hangs a bit out in comparison. I'm not sure how to deal with this cantilevered loads or is it an issue at all?

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Option two which doesn't look as good and puts the wing out further from the car is below. this does resolve the cantilevered issue though. However I will need to change the taillight mount.
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I'm not sure which way to go. The two big issues are that the wing mounts are far apart and are mounted at a angle so the mounts also need to be at an angle.

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No I have not done any wing mount testing since i need a way to mount it first. Once I have that I can raise the wing up or down to compensate for air flow etc.

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