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Hello I have a 91 Camaro z28 with a lb9 305 automatic with a 700r4
I'm experience electrical problems and is causing the car not to start at all and won't even crank the engine. Half of the fuse box has power while the other half dosent. My headlights work, door locks work,windows work, radio comes on and dome light will work, but no gauges move, no buzzer sound when the key is switched to the on position. Before it started happening it worked fine and now it stopped all of a sudden. I don't even hear the fuel pump whining up anymore when key is on. I've checked the fuisble Links at the starter and they are all sending power to the car and I've replaced the fuel pump relay , starter relay and igniton switch and the problem is still there.im not sure where to check now I believe the fuse box is not getting power since I checked with a test light and only some fuses are receiving any power like mentioned above. The battery is charged aswell. I recently installed some headers in the car and checked for any wires that got burnt and I can't find the problem any help would be much appreciated
Could be, but fusible links don't usually fail without a lot of power draw. For instance, if the wire was grounded out on the headers.
Not entirely accurate. They are a thin section of wire that can become brittle over time when suspended next to the starter, bouncing up and down for 100k miles.
I had one go out on me. It wasn't burnt up or anything, physically fine on the outside. Had zero continuity though it so it was an internal break of the fusible link wire.
I have no vats or any lights coming on inside the dash at all. I'm going to replace all the fusible links by the starter today and see how it goes. I put the headers on Saturday that just passed and the car ran very well and I got home and shut it off and on tuesday morning it wouldn't start
"Just put headers on" is a GREAT clue... not that headers per se have anything to do with it, only, that in the process, they got disturbed; and ... just like you or me, they don't work as well when disturbed.
Nope no security light comes on in the dash. I've just purchased 3 fusible links and will replace them all and give it a try.
Thank you for the help I appreciate it greatly
I've replaced all of the fusible links and the car still isn't getting any power same problem consists I'm not sure where to check next
Any help would be appreciated
The car draws its power from the batt/alt, through those. There are 2 main ones, each of which feeds roughly half the car. Your car might have some smaller ones for the ECM and such but that's not where the problem lies. The ign sw for example has 2 batt feeds, one from each FL; those 2 feed everything controlled by the ign sw, including the starter, accessories like the radio and HVAC, gauges, and so forth, split up somehow. The headlight sw (all the car's lights except for turn signals and brake lights) gets its power from one. The brake lights from one of them. The power windows from one. And so on.
What size (color) did you put in? The way they work is, they are ordinarily about 3 or 4 gauges smaller than the wire they protect... so for example, if the big red wire is 10 ga, the FL would be 13 or 14 ga. "Rust" is one common color. Blue is another.
When you install them, you can check the wire they supply, and make sure it has batt power on it. If those wires do in fact have power, then the next thing to do would be to consult the wiring diagram for your car and see where you can most conveniently check for power further downstream (toward the load inside the car). The diagram will also clue you into where to look, by grouping things that don't have power together; once you figure out what all of the dead loads have in common, should be a piece o cake to track back upstream from their last common feed point toward batt to find the disconnection.
If I were the betting kind (I'm not) my money would still be on a fusible link. See my signature for why I think that.
By testing them I am using a test light and I see that the starter is receiving power from the battery. The light shows current is before the fusible link, and even after the test light lights up after the fusible link and is sending power through and I checked all 3 of them and they all seem to work but I'm not to fiamilar with electrical stuff and I apoglize if I seem kind of slow at this. Do I need to follow a diagram and test the wire downstream ? I replaced the fuse link with 16 gauge fusible links. If the power isn't making it to the fuse box would that be enough to stop the engine from cranking and all the gauges not working and fuel pump not priming ?
Cranking power doesn't go through the fusebox. The path is from the big terminal of the starter, through a FL to a big red wire, to the bulkhead connector, to the ign sw, to the neutral safety sw, to the starter. Depending on year etc. it may go through an "enable relay" controlled by the VATS system, DOWNSTREAM OF the ign sw. IOW, even if that goes bad, all it will do is keep the car from starting; won't affect those other things. Again, see my signature.
The key to your issue is, or seems to be, that there are multiple things not working. Now, see my signature... the simplest explanation for, say, 3 things not working, is NOT that 3 things broke, all at the same time! NOT alien abduction, NOT Elvis sightings, NOT a new law of physics!! It's that ONE thing that all 3 of the non-working things have in common, broke.
Electricity is SIMPLE. Gotta be the simplest part of a car. Now granted I'm too stoooopid to understand the really COMPLICATED parts of a car, like the drive shaft or something; so all I can really wrap my 2 brain cells around before they start fighting and all thinking comes to a halt, is the SIMPLE stuff like the electrical system. The SIMPLE concept of power starts somewhere, passes through fuses including links, connectors, switches, etc. to get to its destination, is just so SIMPLE. It's a whole lot like math; if you just put the whole "it's hard" crap out of your mind and decide YOU CAN DO IT, they you can.
A much wiser person than me, smart enough to be a sports team coach, once said something like, "if you believe you can or that you can't, YOU'RE RIGHT". This is no different here.
Still sounds to me like you have a battery feed problem to the ignition switch: all the things you just mentioned - starter, gauges, fuel pump - get their hint to start doing their thing, based on where that switch is turned. I'd be looking REAL HARD at whether power is reaching it.
Remember, ALL THREE of those things didn't just break all the sudden all on their own when you put those headers on: more likely, ONE THING that they all 3 have in common, is farkled. ONE THING. And that ONE THING is somewhere between the batt and the ign sw, and doesn't go through the fusebox.
Your car's wiring diagram should make it obvious. You hardly even need a test light: look at the diagram, find the section of the ign sw that turns those 3 things on & off, look at what feeds it, examine all that which should be nothing but a piece of wire and the bulkhead connector and another piece of wire and the fusible link, you'll find what's broke.
Tommorow morning I will start checking all the wires and use the wiring diagram to help me . I'm a little a confused by checking out ur signature as I am fairly new to third gen.org . I appreciate your help and taking your time to reply I will update tommorow to what I find
The simplest explanation that fits all the facts is most likely to be the right one.
Consider it carefully, one word at a time. "Simplest", "fits", "all", "facts", "most likely". Each word is important... sure, you can invent "explanations" that require alien visitation, divine intervention, luck, one-of-a-kind oddities, a confluence of multiple failures, etc. ... but ... ??? ... is that REALLY how the world works? not usually; "facts" involve observations and data, as opposed to assumptions and guesses; "all" means, if even ONE FACT is inconsistent with a proposed "explanation", THROW OUT that "explanation"; and so forth. You'll see, it's a rule to live by when troubleshooting.
Last edited by sofakingdom; Aug 23, 2017 at 09:16 PM.
I've just checked power where it passes through the firewall and both big red wires are providing power to the inside of the car and then I checked the ignition switch and it's receiving power at the wires and then when turned fully to the cranking postion the rest of the wires at the igniton switch light up . It is passing power after the igniton switch. At this point I'm very confused to what to do. I'm not too familiar with any of the diagrams
Yes sir power is passing through the starter relay when trying to crank it , 2 yellow on big and one small and one black/white have power with the key but there is green color wire that dosent have power at all even when cranking
The windows work, door locks work, radio works, headlights work, all interior lights are working ,and ac controls work, the following things do not work fuel pump, gauges ,and half of the fuse box has no power at all and starter I believe the engine is not getting any spark or fuel since when we try to jump it the car will not turn on
Quick guesses, if ALL fusible links are good now, might be the ignition box at the base of the column, might be the NSS Switch or maybe a burnt/melted wire at the back of the fusebox. I'd start probing with a voltmeter @ the C100 firewall connector PINS A4 ( power to ignition ) G5 ( Power to Fuse Block ),...... Both are RED wires.
These should help; Taken from the 91 Service Manual ---> FOR TPI :
Good news everyone that helped I found the problem it turns out that the ignition cylinder is bad and is not sending any power I managed to hot wire the car by touching a white and red wire under the dash and it fired right up Thank you everyone that helped
I fixed the problem permenatly turns out it was the ignition switch the whole time so I installed a new one and it fired right up Thank you everyone for the help
Best way is to solder, then heat shrink with the adhesive inside.
Glad to hear the OP got his problem solved: it sounds like the "half" of his car that didn't have power, must have been the "half" that's downstream of the ign sw.
You can see from John's wiring diagrams how the power feeds to some of the various loads in the car are distributed, and that if LOTS of stuff other than (or in addition to) the things that the ign sw turns on and off all go out at the same time, the first place to look is those links. (the part of the diagram he posted doesn't include the feed to PW, PS, PDL, wipers, etc. ... but they're all involved too) Logic dictates that when multiple things stop working all at the same time, one should look for the one single most likely thing that can break that would account for ALL of those things, AND NO OTHERS, losing their power feed. Like my signature says...
Best way is to solder, then heat shrink with the adhesive inside.
Glad to hear the OP got his problem solved: it sounds like the "half" of his car that didn't have power, must have been the "half" that's downstream of the ign sw.
You can see from John's wiring diagrams how the power feeds to some of the various loads in the car are distributed, and that if LOTS of stuff other than (or in addition to) the things that the ign sw turns on and off all go out at the same time, the first place to look is those links. (the part of the diagram he posted doesn't include the feed to PW, PS, PDL, wipers, etc. ... but they're all involved too) Logic dictates that when multiple things stop working all at the same time, one should look for the one single most likely thing that can break that would account for ALL of those things, AND NO OTHERS, losing their power feed. Like my signature says...
Thanks...well I'm an electrician on acft...but its slightly different from cars...I would probably put a nice but splice on it and slide and environmental splice over it, heat that up, then slide some heat shrink on it afterwords. I just didn't know exactly what they were was all. Thank god I haven't had any electrical problems yet...does that mainly come from the cars that sat for ever...and or outside for years and years on these third gen things?
Emphasis on "slightly"... electricity is electricity and follows the same rules everywhere, even when wrapped in sheet metal and set up on 4 wheels... only things that are "different" are, the "industry standards" that apply. Common practices and the consequences of how they're manufactured for example. Cars are VERY modular, much more so than most aircraft; also MUCH more mass-produced. And MUCH more cheeeeeeeeeeply built, since cars are SO EXTREMELY price-sensitive, and when car electrical systems fail, people don't generally die.
But electrons behave the same and follow the same rules EVERYWHERE. Houses, cars, planes, ... you name it.
Seems like the main causes of electrical problems in cars are heat, water, salt, poor design, inferior (cheeeeeeeeeeep) materials, and ham-handed previous owners. Not necessarily in that order. Sitting around doesn't bother them much, unless exposed to the elements or other damaging things like rodents.
I fell like you owe us,....... 1 
Please !!! 