Intermittent car electrical problem causing starting issues - any help pinpointing?

Question

I have this starting problem that I've been trying to fix for the past year now. Well, I'm not really a mechanic of any kind, so I spend ungodly amounts of money to local car mechanics for "maybe" fixes.

Unfortunately, none of them have been able to pinpoint and fix the problem. And quite frankly, I'm running out of money. Can anyone help me identify what the root cause of my starting issues are so that my next expenditure won't be for naught?

Here's a video of my car issue: https://youtu.be/q0b2f1U6w1U

Facts: (1) This doesn't happen all the time, but I can confidently say that it happens more frequently than it does start fine. Sometimes it starts up perfectly, other times I have to turn my key 10x more than I did in this video.

(2) Starter solenoid and starter motor have been inspected, and found to have no issues. The carbon brushes have also been replaced for good measure (also since we were already inside the starter motor so why not).

(3) Starter works perfectly fine - as in no hiccups - when power is applied directly to it from the battery. This only happens when starting it through the keys

(4) Battery charge / power level is fine. Tried swapping in a different battery to little avail.

Other facts that may be relevant:

(1) The car alarm and door lock has some sort of relationship with the ignition system (sorry, I don't know the right terms). If you don't unlock the car through the remote before trying start it through the keys, the alarm will sound.

Pretty standard behavior, I know, but the thing now is that unlocking no longer works - only locking. Not to worry. I just press unlock anyway even if it doesn't unlock the door just to trick the system and not trigger the alarm. (I do hear it make rhythmic/systemic clicks though). Could a short or some problem within the door/alarm system be the actual cause of my ignition problem?

(2) Interior cabin lights on the roof sometimes do not work. I haven't had "gotcha!" moments when they both act up at the exact same time, but their intermittent-ness is pretty similar

Any input would be very helpful. I am actually selling the car, and this is one of those problems I aim to fix first to prevent a huge depreciation hit.

Thanks in advance!

EDIT: Forgot my specs

1996 Suzuki Vitara G16B 1.6L Gasoline, EFI

Answer 1

It appears your issue may be related to the power delivery from the battery. The symptoms you have described here as well as in the video seem to point to this. As you said the starter works flawlessly when directly coupled to the battery and it does appear that the battery voltage is getting pulled down when you try to engaged the starter in your video by the way the dash lights dim. If there is too high a resistance in a wire or perhaps a ground connection is not making a solid contact this could cause intermittent starting issues as well as the others you have described here. I would first check a couple of voltages with a multimeter whilest the car is off. Check the readings directly at the battery itself as well as the terminals as sometimes a slight air gap can form between these two components and cause a massive voltage drop. If all of that turns out normal - somewhere between 12 to 14 volts - I'd then try to check for voltage at the starter solenoid. On most vehicles the positive side of the battery is connected to the solenoid via a fusible link - a plain looking wire that will burn up when too much current passes through it. Overtime this link may degrade and could cause your issues with starting, however, this most likely would be unrelated to your other symptoms but it's still worth checking. And finally, I know this is long, I'd check for voltage drops across both engine grounds and body grounds. Best of luck to you.

Answer 2

I had a similar problem with my car (intermittent starting problem). Sometimes it started just fine but other times I just heard a clicking noise and then nothing would happen. I also checked the whole starter and solenoid and replaced anything that could cause the problem. I also checked the battery and it was fine. No one could solve or analyze the problem. Finally, after lots of research I found that starter signal wire (the thin wire that goes from ignition switch to the signal terminal on the solenoid) was faulty. I used a method called Voltage Drop test to find the issue. However, since it was beyond my scope of abilities to replace the wire with a new one (it required disassembling part of the dashboard), I installed a 12V relay and it solved my problem. It now starts nicely every time I turn the key.