My FC has become an electrical nightmare. please help.
 

I'll start with the largest problem, starter spins, engine doesnt even try to start; if i pop start the car it starts right away. sounds simple but it's proven to be a tricky little gremlin. runs perfect once started though.

two years ago i did a 10ae interior swap( including dash harness and accompanying lock set) then last year i did the battery relocation to the passenger bin and turbo setup on the stock block, same engine harness all the same electronics except those needed for a tii ecu. running an rtek 2.1 ecu.
also wired various other electronics in the car (plug and play bixenon HID's, indiglo guages, boost and oil pressure guages, wideband)


now from the start! my first problem was the clicky starter issue, just kind of dealt with it.

the switching diode for my HID's burn out, one at a time, i replace them and shortly after comes the loss of my low beams, the highbeam indicator light is always on, i try to switch them off and the relay clicks, the lights flick and nothing changes, only does this once unless i turn the ignition on then off again. i replaced the switch and the relay, no difference.

one of my headlight motors dies, i replace it, it works at a different speed than the other one, but works.

then my left blinker started to flash fast, both bulbs intact, replaced the blinker switch. once again did not help.

same side headlight motor shits the bed, again.

some point around here i finish my turbo setup, from some reason i wasnt getting my 5v+ reference signal to my map sensor or tps, so i tapped in the 5v signal going to the airflow meter, problem effectively bandaided.

ONCE smoke came out from under my dash while it was warming up in the driveway, it stopped on its own, almost immediately, never happened again, could never find the source.

also noticed at some point that my horn only likes to blow once then stops working until i cycle the ignition switch.

then my stereo started to fail intermittently, eventually totally.

i finally get some free time, double check my cables for the battery relocation, they're fine. added an extra grounds from the alternator to the ground cable that meets the chassis then starter and beefed up the ground that runs to the firewall. didn't help, but atleast its off the list.

found that the remote wire to the starter was only getting 6 volts, so i wired in a new 12v relay and ran the remote wire directly off the start position of the ignition switch. This helped!! for a day..

the next, day i ended up stranded with it at work because it wouldnt start. it would turn over gloriously but not start. push started it and it fired right up, ran great, got it home.

then my right side blinkers start blinking fast. again, both blubs are good.

the next, next, day i pulled the dash half apart, in search of any burnt, melted or split wires, fuses or connections. everything i looked at, looked fine.

So i then went on my theory that the ecu wasnt getting full voltage while starting due to it turning over fine and pop starting fine. i was right, switched power to the ecu was only 5 volts. SO i wired switched power to the ecu directly from the ignition. and it helped!! for a day. after a few cycles of turning on and off it began to take longer and longer to start, eventually falling back into the same turn over but no start pattern.

also now my electric fan stays running after i shut off the car (its wired to switched power as the signal on wire) so somehow the ignition is back feeding into itself after shutoff.

i haven't yet measured the voltage at the ecu to see how its changed, but i'm done bandaid-ing the electrical system in my car, i need help fixing it correctly

i have checked for a short circuit via measuring from current between the - battery terminal and the chassis, in all ignitions points except when its actually running and there was none.

I have a battery disconnect switch that i use every time i'm done with the car so atleast i don't need to worry about it having a sporadic electrical fire in the meantime.

Im at the end of my ability without tearing the car apart and starting from scratch which i really don't have the time for. I really need some help in the right could as to what can effect all of these systems, what could be causing the issue.

i know its a lot to read, thank you for any advice! This is going on a two year problem, and downhill fast. I just want to drive my car!

Is that all? Checking grounds is a good thing but adding them isn't really necessary if the original grounds are up to speed. For example, the alternator grounds to the engine so there is really no need to add a ground as it is a waste of time.

Not really sure why people insist on the battery being moved to the rear. Seems for every person that does it they end up posting on this site why it's not working the way it did when it was just fine where it was initially.

The blinker problem could be rust built up in the light sockets or the little indicator bulbs in the dash are problematic or the wires at the CPU for the flasher relay are poor and a cold solder is preventing them from working as they should.


The starting issue could be a function of low compression or the starter is not turning quickly enough which could be caused by too low amperage.

The headlight issue could be that they are requiring too much power to run and it is taxing the wiring system or the grounds for the lights are in need of cleaning.

And then the wiring harnesses might be just in too poor of a shape to continue to work effectively.

And when you measured switched power at the ECU was this w/key to on and engine either off or on, or w/key to start?

No I inspected all the factory grounds and added one at the map sensor per Aaron cakes write up. Added the ground at the alternator to the chassis because it can't hurt and I'm getting desperate.

Battery was relocated due to intercooler piping interference.

Bulb sockets aren't rusty, it could be the CPU but if it is its likely just another piece of the larger problem.

Compression is strong, starter turns over fast. Just not getting fuel or spark while turning over due to voltage drop at the ecu.

The HIDs draw the same current as factory, plus it won't shift to the low beam circuit even with the headlights unplugged.

The wiring harness is still in question but the only way to get total inspection on it is to pull it, which is what I'm trying to avoid unless absolutely necessary. The harnesses aren't brittle cracked burnt or melted anywhere I've looked.

I've measured voltage to switched power to the ecu at off, accessory, on and start positions. Like I said it was measured last time I had "fixed it", I still haven't had a chance to touch the car since.

I really would like to know what can be causing so much voltage drop without any direct signs, and effecting the voltage of other random systems around the car like it is

The dimmer relay needs to be looked over then. The low beams change to high beams when the White wire has a ground on it thus the relay needs voltage on that wire for the low beams to activate. A sticking relay could also prevent the highs reverting to the low beam mode.

Pin 3B of the ECU should see no lower than 8 to 10 volts w/key to start. Same goes for pin 3I. Perhaps you need a higher amperage alternator.

Smoke from dash is a direct sign. Sounds like faulty wiring under dash. Find the source of the smoke.

And specifically look over the wire that comes off of pin 3B at the ECU. Wire color starts off as Black/Blue then converts into a B/W wire at FEM-02 as it then runs to circuit opening relay.

I've replaced the dimmer relay and it didnt help.
Pin 3b was seeing 5 until I rewired it then it was seeing 11 but I have to re-measure it now that it doest seem to be working again. Pin 3i had 12 but that also may have changed.

Running a Third gen alternator, in good working order.

I know the smoke under the dash was a bad sign but like I said I have looked but couldn't find the source, may have a shot if I pull the dash but I would really prefer not to.

I'll look into the b/w wire coming from 'fem-02' .
anything that may get me closer to finding the origin of the problem i happily look into. I'll have a chance to work on the car some more tomorrow afternoon

The replacement of the relay and or switch could be immaterial for it might be bad. The bottom line is, diagnosing this problem is straight foward, for either the White wire at the relay has a ground or it has close to 12 volts. It can't be both so just spend the fraction of a minute to measure it. When the wire has 12 volts the low beams work. When the wire has a ground the relay closes and the high beams work. If the voltage checks out for both situations and the high beams still stay on then the relay is stuck closed.

I'll take the half a minute tomorrow when I'm not working two jobs. That should be helpful in understanding the headlight issue, thanks! However I would guess its seeing partial voltage alike many of the other systems in the car.its all a step in the right direction though

Get over the 'don't wanna pull dash' idea. It's worth checking.

Its certainly worth checking, my issue is more so that I work 2 jobs, I don't have a garage to work in and have very little free time so if I can avoid tearing my car apart that much and a ton of time searching for something that I don't even know what I'm looking for, I would like to explore those options.
If I can't come up with anything and that's my only option, I absolutely will do that.

How is your battery grounded to the car? If you didn't run 2 or 4 gauge wire to the motor, directly from the battery, you did it wrong.

ummm, no.

From the factory, the battery grounds at the driver side strut tower and then goes to the starter from there. Adding a 2 or 4 gauge ground to the motor is senseless.

The battery has both a 2 guage and 6 guage ground directly to bare metal on the chassis within the rear bin. Engine is grounded at all factory points, plus from the engine to strut tower, and map sensor to chassis.

Is there a ground for the dash harness I could be missing?

Not specifically. Look at the bottom of the wiring diagram and it will list all the ground points for each of the electrical circuits requiring them.

My factory ground goes straight to the engine block and a smaller wire branches off in the middle to the strut tower.

There is a big cluster of grounds under the dash but it's way up on the steering column support, behind the gauge cluster.
Not the kind of thing to casually go missing, in other words.

Although I can see how circumstance makes it difficult for you, I must say that pulling the dash is really not that big a deal.
The first time, yeah, it's a PITA but after that, pretty simple.

Two hints (especially if working alone):
Remove the steering wheel and unbolt the ebrake handle.
Getting those two things out of the way makes it a lot easier to horse the dash out of the cabin.

I've already done a dash swap before which is why I was avoiding it. But because I want my car running I nutted up.
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Dash ground wasnt connected! Imagine that!
Though yet to see if that was the problem.
I'm going to look through all the body harness wiring and put the dash back in now. Keep your Fingers crossed for me guysm also any last minutes suggestions to other theories are still welcome!!

Found the source of smoke! I had tapped into the 12v switched power for the power mirror switch in the center console for my nitrous purge switch, well that wire is all melted from there to the connectors by the fuse panel behind the dash to as far as I'm not sure yet. Ive started Pulling the wire from the rest of the body harness, section by section. Looks like its going to be a hell of a process but maybe this will at least end all the problems I've been having when its all said and done.

all of the melted wire is out. Soldering in its replacement and getting everything back together is tomorrow's project! Thanks for convincing me to pull the dash. Absolutely zero chance I would have found this otherwise.