Need electrical help as this does not make sense to me. How can this even happen...

[Chrisw]

LAYOUT

- Car is an S14 with an S15 SR in it.
- Battery is in the trunk and is grounded out in the trunk.
- Large gauge wire runs from the trunk to the front engine compartment, to the BLK side of a 150A fuse.
- The RED side of the 150A fuse is hooked to where the original power post hooked up in the original battery location.

http://img838.imageshack.us/img838/4089/img0848sh.jpg

PROBLEM

- I get 12.**V at my battery.
- I get 12.**V to the BLK end of the fuse ONLY when the fuse is not attached. (If i hold the black wire in my hand)
- As soon as I connect the fuse to the BLK wire, I get 00.2*V.
- When the wires are connected by the fuse the car gets no power.
- I can boost the car by by connecting a + boost cable to the RED side, but if I connect the + boost cable to the - side it still gets no power.

CONCERNS

I was able to start the car under it's own power with the fuse connected last friday. I drove it to the gas station and turned it off. It didn't start again after that unless I boosted it from the RED side. From what I know, a 150A fuse is large enough (and it allowed the vehicle to start on friday with it installed). The fuse was installed almost 2 years and go and the car has run with the fuse installed many times.


PLEASE LET ME KNOW IF YOU KNOW WHAT'S WRONG.

THANKS.

Also, where is the main fuse for an S14 car located?

[Sileighty_85]

Shitty ground or not enough grounds?

[Chrisw]

Shitty ground or not enough grounds?

Not enough grounds? I need more then one? I have the batt grounded in the trunk. Where else would I need one?

_______________________________

Ok, so I played around with my ground a bit and I think that's what it is. I have the batt grounded out to this bolt. Is this a good enough ground or should I use a bigger bolt, ect....??

http://img843.imageshack.us/img843/8557/img0850v.jpg

[Chrisw]

So I tried taking the - cable from my booster cables and hooked one side to the - terminal on the batt. I then took the other end of the cable to a solid ground point in the engine bay and they batt works fine! Looks like the ground point in the trunk sux.

ANY ADVICE ON HOW TO MAKE THE REAR GROUND POINT ANY BETTER??

[GSXRJJordan]

You need to clean all the paint/grime out from under that ground terminal, assuming your crimps are good. You want to ground to metal that is welded to the frame (since the engine grounds to the frame up front).

I'm also concerned that you have the fuse out of the holder, sitting on rusty metal. Could start a very nice fire around that long black power wire you ran through the car (interior fires suck).

[Chrisw]

You need to clean all the paint/grime out from under that ground terminal, assuming your crimps are good. You want to ground to metal that is welded to the frame (since the engine grounds to the frame up front).

I'm also concerned that you have the fuse out of the holder, sitting on rusty metal. Could start a very nice fire around that long black power wire you ran through the car (interior fires suck).

The fuse is simply out of the holder while I was checking the Volts. It is usually inside.

I cleaned the terminals this afternoon with a wire brush attachment on a hand held drill. Did a good job. How do I know if my crimps are bad?

I assume my crimps are where I have the large gauge wire into the flat ring that bolts to the batt terminal....?

[Sileighty_85]

like what Jeff Said ^^

I'd branch off to more grounds.

Have one to the shock tower strut and another to one of the trunk floor board grounds.


Also you need to ground your engine to the chassis, If not your Alt might not charge as well and starting the engine will suck and possibly burn up small ground wires from trying to pull too much amps through them

[army240]

Also, just for your info... you should have installed your fuse as close to the battery as possible, because your wire is only safe after the fuse, not before :P

The way it is installed now, the wire passing trought your car is not protected. I mean, if it short to the ground, it will melt, put your car on fire, probably make your battery boil and finally explode if there is a spark close to it!

Frank

[Chrisw]

like what Jeff Said ^^

I'd branch off to more grounds.

Have one to the shock tower strut and another to one of the trunk floor board grounds.


Your suggesting I have several separate ground wires coming from the negative terminal of the batt and grounding in separate areas? (the one I have now and then the shock tower)

[Sileighty_85]

Your suggesting I have several separate ground wires coming from the negative terminal of the batt and grounding in separate areas? (the one I have now and then the shock tower)

Correct have them branch off the neg terminal

Then find some clean spots on the engine and run some ground points to the chassis

[Chrisw]

Ok, Now I'm stumped again...

If I leave the car as is, and take the negate wire from my booster cables, attach one end to the negative batt terminal, and the other to a rear strut tower bolt. The car starts.

Well I thought my problems were solved, I went out purchased a length of 4 gauge, and ran a SECOND negative ground from the batt, to the exact same bolt. Car wont start. As soon as I try to turn it over, the starter doesnt get enough power and the electrical system goes down.

The wire running the the back of the pic is the new ground that I just put in...
http://img580.imageshack.us/img580/1598/img0853y.jpg

So I take out the wire from the booster cables and try it again... car starts. WTF?? I believe that the booster cables are 4 gauge (looks like it anyways).

I also now have two grounds from the engine to the chassis (one on each side of the engine).

Any other ideas of what I can try??

[shiftdrift]

clean off your cable connections/crimp connection points and the actual bolt connection point. it has to be a bad ground, grind it down to bare metal.

[Sileighty_85]

take the wire from the shock tower and bolt it to the trunk floor

[Chrisw]

Thanks for constantly checking in and helping guys. I really couldn't work on this car without this site!

clean off your cable connections/crimp connection points and the actual bolt connection point. it has to be a bad ground, grind it down to bare metal.

I'll try this, but they are already pretty clean.

take the wire from the shock tower and bolt it to the trunk floor

With just a nut and bolt or do I need to get a bolt welded to the trunk floor? Any spot on the trunk floor will do (just below the batt box)?

And just so I understand... Why will this help? If I have what appears to be a sold ground point on the rear strut, why ground to the trunk floor?

[Nizzan4u2nv]

Run all 0ga. Do you still have a ground between engine and chassis?

[Chrisw]

Run all 0ga. Do you still have a ground between engine and chassis?

0 gauge??? Do I really need that?? And yes I still have two grounds between my engine and chassis...

[Nizzan4u2nv]

General rule is youre suppose to step up in size if youre gonna move it to the back.

[shiftdrift]

Mine is entirely 0 gauge.

[Sileighty_85]

With just a nut and bolt or do I need to get a bolt welded to the trunk floor? Any spot on the trunk floor will do (just below the batt box)?

And just so I understand... Why will this help? If I have what appears to be a sold ground point on the rear strut, why ground to the trunk floor?

There should be a spot on the back left side corner

cuz technically when using the strut tower bolt, Its actually part of the shock which really dosent make good contact with the chassis unless you clean all the paint off around the stud for a real chassis point.
Ive found when using a floor board bolt you get better results, since those bolts into the frame

[GSXRJJordan]

You certainly do not need 0ga for a stock 80A alternator.

I'm concerned that you say you connect one side of the booster pack to the battery's ground and the other side to the chassis, then start the car ~ there should be continuity between the battery's ground and the chassis, and you're adding 12V with your booster pack.

Either your battery is not hooked up, or you grounded your starter's main batt post, or something. I suspect you have a fundamental flaw rather than a dirty terminal/etc.

[codyace]

I'd start by disconnecting the power from both the starter and the alternator, and seeeing if you have 12v then through that fuse. I'm with Jeff, I think there is something simply hooked up wrong.

[Chrisw]

:( I'm soooo horrid with wiring in the first place!! Haha. This Friday I will make sure my ground has a sold connection on the trunk floor, and will also take the power off the alt and starter to see if I get power through the fuse.

My starter is also completely done so I will replace that but I'm not sure that has anything to do with my elec problem...

And Jeff, do I need this bolt welded to the trunk floor or can I just drill a hole and bolt one through? I don't believe I have the bolt that you described as my car is now completely stripped...

[codyace]

And Jeff, do I need this bolt welded to the trunk floor or can I just drill a hole and bolt one through? I don't believe I have the bolt that you described as my car is now completely stripped...
Clean sruface with nut/bolt is just fine

[GSXRJJordan]

Yeah the surface needs to be totally bare metal, but a nut and bolt through an area that's welded to the frame is fine. The trunk floor is popular, strut towers are good too.

While on the subject, you guys with roll cages can totally weld bolts to the cage for grounds, they work AWESOME.

[copmagnet]

And like was said earlier, PUT THAT FUSE NEXT TO THE BATTERY!!! RIGHT AWAY!!!!

As someone with almost 2 decades of electrical experience, I can't stress that enough. The fuse is there to protect the wire, and it only protects AFTER it, the wire before it is screwed. As it sits, if you ground out anywhere between the fuse and battery, your car is done. Seen it happen too many times. Also, my battery is relocated with only 4 gauge wire. Has been for 2 years with zero issues, but yeah 0 gauge would be nicer, especially if you do the Quest alternator.

And grounds are very important, make sure the engine block is grounded to the chassis well, and make sure that ground in the trunk is to bare metal.

[Chrisw]

And like was said earlier, PUT THAT FUSE NEXT TO THE BATTERY!!! RIGHT AWAY!!!!

As someone with almost 2 decades of electrical experience, I can't stress that enough. The fuse is there to protect the wire, and it only protects AFTER it, the wire before it is screwed. As it sits, if you ground out anywhere between the fuse and battery, your car is done. Seen it happen too many times. Also, my battery is relocated with only 4 gauge wire. Has been for 2 years with zero issues, but yeah 0 gauge would be nicer, especially if you do the Quest alternator.

And grounds are very important, make sure the engine block is grounded to the chassis well, and make sure that ground in the trunk is to bare metal.

ok, so it's not that I'm too lazy to move the fuse... I don't know how. :(

The fuse was installed in the first place to make the batt relocation simple. I needed a way to connect the line that I have run through the car to the existing wire that was already there... The fuse was the only way I knew how. If I move the fuse, I still wont know how to connect these two large wires... :S

[copmagnet]

So get a circuit breaker or fuse and put it in the back. The extra fuse/breaker won't hurt anything, but it could save your car.

[Chrisw]

Ok, So I have made a solid ground, and someone I know noticed my starter was crapping out so I replaced that.

The car's electrical system comes one, and when i turn the key, the starter cracks strong, but she does not start. I'm just learning about this car and am not sure what to check next... :S

Any advice of what to check next?

Here is a video of what the car is doing:

http://www.youtube.com/watch?v=SFzDSEvThIg

[codyace]

Sounds like starter isn't in correctly, or that yo udon' thave enough juice going to it

[Chrisw]

Sounds like starter isn't in correctly, or that yo udon' thave enough juice going to it

not sure how I could install it wrong.. It's two bolts. But I'm happy to try anything in regards to that if have anything to suggest.

So you think it is still a power issue? I assume my next step is then to rewire the starter? I have a friend who can likely help me do that. I know there are flow charts out there showing this wiring set up. Anyone have one they can share?

[Chrisw]

Ok, soI found this one but I believe it is for an S13. Is it the same for an S14? Im also trying to figure out where in this diagram I break off power to run it to the fuse box...

I'm still having issues with the car and would soooo desperatly like to get it running. Any help would be great and thanks to those that have helped so much already!

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-snc6/259908_10150665425195243_510650242_19131942_206159 3_n.jpg

[Mishkin_707]

The fuse you have on there, is it blown out?

[GSXRJJordan]

That diagram is correct, but you don't really need a fuse in there. Lots of race cars tie that excite wire to switched +12V though to avoid a possible power drain through the alternator.

[Chrisw]

That diagram is correct, but you don't really need a fuse in there. Lots of race cars tie that excite wire to switched +12V though to avoid a possible power drain through the alternator.

Ok, I will try to set this up this weekend so I can finally have this thing out to the track. I'm running out of track days!!

The fuse you have on there, is it blown out?

Nope, fuse is not blown.