Wiring Nightmare Causing Tons of Issues (420a, A/T)

[gunnermaiden]

Hey guys, long time no post!

I did search before posting but it seems like everyone's electric problems are pretty dang specific, couldn't find anything that answers my question.

So I went out to cruise in my car yesterday and finally it didn't start for the first since I owned it (bought it last year).

It's always been a pretty hard starter, but usually if I depressed the gas pedal just a bit it would be enough to get it going. The last time I drove it, it stalled out at a light but kicked over right away when I turned the key then was fine. (After I just typed this and thought about I should probably make sure there's no fuel clogs too..)

I had it parked in a cool garage for about 2 months after that. (I attached a photo), I found really bad corrosion (which is new) on the positive battery post, traced the wire to where it was grounded and it looked pretty bad on both ends. Obviously I'm going to have to replace it as it's pretty fried.

Now my questions:
1) I'm looking for a battery cable, none of the new ones I'm finding are labeled positive or negative, does this matter or does it only matter how they're mounted/grounded?
2) As I mentioned my car was always a hard starter, could it really have been just that one cable all along or are there other things I should examine electrically too? (The car does click when trying to start, but I can't tell where it's coming from).
3) This car has a million things wrong with it electrically, what are some other symptoms that bad battery cables could cause? I checked the negative wire and it seems to be in good condition and it is properly grounded. I'm hoping I'll kill 2 birds with one stone by replacing the one cable

I should note that the second pic is how the previous owner rigged up the power to the HID kit they installed (thin red wire). I'm suspecting that had something to do with how the cable got fried in the first place as that does not look appropriate to me at all. I disconnected the kit as of yesterday and am planning on redoing it a better way.

 

[spyderdrifter]

1) Your wires will never be physically labeled positive or negative. Generally positive is red, negative is black. When replacing the battery cables, you should keep these cables the proper color so you don't accidentally swap them on the battery. But if you don't keep the colors the same, they do have the exact same copper wires in them.

2) Yes, a bad battery cable that is highly corroded inside could cause any number of electrical problems. If there's corrosion inside, it's disrupting the current flow. The clicking you're hearing is most likely the starter, that's normal to hear when the battery isn't giving enough power to start your car. That also lets you know your starter is working even though the battery isn't. If both of your cables happen to be corroded, if you don't know, you should look at the other one, the battery could be suffering from lack of charge from the alternator since you said the positive cable is corroded. However, you need to be sure on that since you said the positive was grounded, and that's not how the system works. The positive should never be grounded, only the negative cable.

3) Bad battery cables could be the link to many electrical issues indirectly, all caused by a lack of charge from the alternator. Replace that cable first, and see if there's any change in the rest. Your electrical problems could all be from that alone, but you may not be able to tell until it's replaced.

Since there's a bit of corrosion on the battery, be sure to clean all of that off. Even clean up with a little water, but be sure everything is dry before clamping on the cables. Hope this helps, good luck.

 

[tunedbysaturnsl]

I'll second the battery cables. In general to a faulty cable itself, make sure they're tight. I got stranded back in the day due to loose cables at the battery terminals. I replaced the clamps since they've seen better days and used some of the anti-corrosion grease on them as well.

 

[spyderdrifter]

That anti-corrosion grease is debatable. I know people who swear by using it, and that's all fine. I have never used it on my cars, ever, and I've never had battery corrosion issues. That being said, I've also known other people to use the grease and the felt pads and can't ever get rid of corrosion.

 

[gunnermaiden]

@spyderdrifter: Thanks for answering so nicely and with tons of detail! Yikes on #2 about the positive not needing to be grounded. The bottom half of the first picture I uploaded is where the wire is "grounded". Does that look right? I can't find anywhere in my old book I have where it's actually supposed to end up, guess it's missing a few pages I didn't know about

Oh and my cable is actually labeled as positive which where I got that thought from, right on the metal head that touches the inside of the clamp it has a "+" stamped on it. I'll upload it later as I don't have a photo right now to show you what I mean.

@tunedbysaturnsl: I'm going to take an old toothbrush and clean it up gently with Coke, I've seen that suggestion on here quite a lot and it seems to be working well for other people! (Someone stop me ASAP if this is wrong!) My clamps were tight as Hell when I went to remove them, I actually had to tap them loose they were so tight.

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I have a few questions about wiring aftermarket HID kits as well, can I ask here or do I have to start a thread somewhere else?

 

[spyderdrifter]

No problem, I like helping whenever I can. The portion of the picture you're asking about is the starter, not really a ground (Don't qoute me on that just yet though). There's only the 2 connections attached to the starter, one veing the cable, the other being the little plug. I'd need to go look at my car to be sure which cable is the large one, but I think it's the negative cable, but I need to go lool to be sure for you.

As for the HIDs, I think you'd be better off starting a new post so you can keep the topics separated so things don't het too hectic in one. The previous owner of my GS installed HIDs, so I'm pretty sure I could come up with a wire schematic dornyou to hook up your own.

 

[1990TSIAWDTALON]

Take a set of jumper cables and clamp them on the ground of the battery then clamp the other end to the engine....see if it turns over. Do the same with the interior of the car, clamp a ground in there and see if your problems are still the same or improve. Just an old mechanics trick for checking for good grounds and will keep you from pulling a million fuses just to find out you needed more or a proper ground. Give it a try.

 

[gunnermaiden]

@spyderdrifter: Let me know how yours is setup. I found 3 more manuals and it looks like it's supposed to be connected to the starter motor but there's not really a good conclusion I can get out of them.

Also, I found a few other posts on DSMtalk about how this was happening to other GS's and they found out it was their anti-theft system. The manuals suggest that's factory, however since P.O hacked the car up pretty bad I honestly can't tell if mine has one, or if only some GS's had them. I do know my car has power locks if that helps.

@1990TSIAWDTALON: My interior wiring is even worse than my engine wiring, I still haven't found everything in there yet. I will keep that in mind, never heard of that trick!

 

[1990TSIAWDTALON]

@spyderdrifter: Let me know how yours is setup. I found 3 more manuals and it looks like it's supposed to be connected to the starter motor but there's not really a good conclusion I can get out of them.

Also, I found a few other posts on DSMtalk about how this was happening to other GS's and they found out it was their anti-theft system. The manuals suggest that's factory, however since P.O hacked the car up pretty bad I honestly can't tell if mine has one, or if only some GS's had them. I do know my car has power locks if that helps.

@1990TSIAWDTALON: My interior wiring is even worse than my engine wiring, I still haven't found everything in there yet. I will keep that in mind, never heard of that trick!

It just keeps you from running thru 20 some circuits or more. Its a good "test" then you go from there.

 

[gunnermaiden]

I took out the bad cable and just got done installing the brand new one, cleaned up all corrosion and degreased a good section of the engine bay while I was is in there. Charging the battery up right now and going to do a test start later after charging is finished. My lights are off the car right now so I won't be able to drive it until morning (assuming it starts).

I'll let you you guys know the results!

Edit: Found a complete diagram and the positive wire does post up onto the butt of the starter. Extremely easy, turns out. My bad.

 

[spyderdrifter]

Hopefully this solves your problems

 

[gunnermaiden]

Update: Still a hard start, but it did start.

Took me about 5-10 minutes to get it to turn over with a freshly charged battery. Still had to depress the gas pedal but it really only went after I quickly turned it from OFF to ACC about 10-12 times, then it rose out of the dead pretty slowly. Tested it after it warmed up, turned car off completely off and then turned it over succesfully about 6 times after first startup.

Can smell oil burning on startup and it occasionally backfires (no flame), not sure if that could be electrically related or not so I'll mention it anyway.

However, I was able to run all of my (connected) lights, crank the A/C, lock/unlock all doors with no stall out problems and no dash lights fading in and out so that's a plus.

Was not able to drive as someone so kindly blocked that section of my driveway, so not sure as of yet wether or not it helped during driving.

Any ideas? I'm thinking the actual starter itself, the key ingition, or the wiring between the two. No idea where to start.

 

[Vegas Smith]

I just replaced my starter cables last week. It's really simple (for my 1g at least) Positive cable from battery to starter. Negative cable from battery to transmission bolt/starter.

IS the engine turning over/cranking when you attempt to start or is it not even turning?

 

[gunnermaiden]

@Vegas smith : I did figure out how to wire the battery cables, and it was easy ^^. It is cranking but it's a REALLY hard start.

I also just realized after turning to the next page in my diagram that the starter relay is behind the radio. In my case, previous owner completly hacked the radio harness apart and probabaly chopped up the relay as well thinkng it was part of the stereo. There is no stereo in my car due to previous owner messing with things before my time so I'll be abe to easily access it. I am going to go check that right now as that might be my problem!!

 

[Vegas Smith]

If the car is cranking at an appropriate speed then the starter system is doing it's job. It may be some type of fuel/air issue.

 

[gunnermaiden]

@Vegas smith I'm thinking there is a fuel issue somewhere. What's funny though is when I took ti soemwhere about 7-8 months ago to have the A/C issues woked out, I didn't have to depress the gas pedal to get it to start until the A/C was repaired. Which is why I'm still thinking there is an electrical problem somewhere.

 

[gunnermaiden]

Found this wire balled up and shoved under where the ECU is sitting (under center console). Checked my diagram with where it's supposed to lead to and routed it through but I don't know where it plugs into. Any particular reason why previous owner would do this, should I plug it back in?

I should note that there are NO major performance modifcations at all. Cold air intake and headlights are it.

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Also, here's a pic of the mess behind the radio:

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2 loose harnesses (assuming they belong to the nonexistant stereo, one hanging from the top and one coming from the bottom) are tucked out of the way in this pic.

 

[Nathan1993]

I also have had, and am having issues with my 420a. My car has a full wire tuck and has a lot of the stuff unhooked/hacked. Granted I have the egr deleted, but I have the same hard start/stall and shut off issue. I cleaned up my air filter and it seemed to get a bit better. I know I have valve seals that are going out but that may play a role it it as well (I'm not sure). If you find something that works, let me know. Another good thing to check would be the fuel filter.

 

[PlanZero]

That plug is for the stock amp. No need for it anymore. The bottom pic isn't bad I've seen much worse. The loosely wrapped jumble of wires is how the stock wire harness looks.
A bad coolant temp sensor ($20 from any parts store) can cause all kinds of hard start problems, seems like more so on a 420a. Years ago I had a similar problem, replaced the CTS and it was fine. Actually I had to replace the plug on the CTS since the wires were cracked. Symptoms were just like yours, only difference was it was winter.
Also check the tps and throttle cable since you're having to open the throttle to start it. Slight chance something got knocked loose while they were messing with your ac.

 

[gunnermaiden]

@PlanZero :Thanks for clearing that up, I'll just remove it then. And where are both the TPS and CTS located on a 420?? Been searching on here for about an hour now and I'm finding is the GST's/X's and 1g's but nothing on the 420a. I'll deff check the CTS, didn't think of that.

Some more random symptoms are rough idling, hesitates to accelerate, running rich, all of which I read could be the TPS.

 

[gunnermaiden]

@Nathan1993: cleaned out all my air filters and I'm yet to check the fuel systems, follow my thread because I fix it/find the issue I will defintely update the post!

 

[gunnermaiden]

Edit: found the CTS, scratch location request. How loose should the CTS gauge unit wire be? My hand hardly skimmed it and it popped right off from the unit like nothing.

 

[PlanZero]

You probably hit the wire for the dummy gauge. That sensor has a spade connector, the CTS has a stout plug that should be clicked together. I forget if the CTS on a 420 is below the temp gauge sender like on a 4g if not it's in the same vicinity. If you have a Haynes or Chilton manual it should tell you. If you don't have one pick one up off eBay used for like $5-10

 

[gunnermaiden]

@PlanZero : found the plug, didn't have time to mess with it yet today but I'l check that coneection, I've already found a few plugs that were loose/cracked elsehwere.

Does anyone know a quick way to test the TPS and the CTS?

 

[1990TSIAWDTALON]

Unplugged and a multimeter on pins 2 and 4. Ohms should be around .58-.63 and swing to 5.0 volts plus or minus a few tenths. I just checked 2 of mine that way, they were 4g63 cars but I don't have link in them so I had to do the ohms method. Here is the write up I used......