1994 Mustang GT money pit I mean project

Discussion in 'All Non-S197 Media' started by joe_momma, Nov 18, 2020.

  1. joe_momma

    joe_momma forum member

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    I ordered an AC Noise Condenser off a recommendation from a user at the SN95 site. It attaches to the coil. They are prone to fail, and mine looked original and I'm not sure if it is even connected.

    Went to the muffler shop last night and got the Borlas installed (ProXS). They definitely tamed down the exhaust some. It still sounds good, but not as obnoxious. I'm not sure on the drone yet, I took the backroads home as it was a straighter shot. It's a pretty mellow tone, and I think it's going to sound pretty good at WOT. I didn't have a good chance to really get into it. Turns out the factory cats are gutted, so we just left them in place. There wasn't any heat in them and you could see where they had been cut/welded. That would also explain the raw exhaust smell. I also had him weld up the bung where the smog pump went in, I previously just had a hose with a spark plug clamped on it.

    I tried to look for the block to chassis ground while it was on the rack, but had no luck. I also saw the name plate/plaque on the header, but I couldn't make the brand out.
     
    golkhl likes this.
  2. joe_momma

    joe_momma forum member

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    Over the weekend I got the noise condenser installed, along with the engine to chassis and battery to chassis grounds. I just added 1/0 gauge wires in addition to the existing cables. It wasn't bad, but it wasn't terribly fun either. I also installed those ferrite core things to the RCA inputs at the amp.

    And, I still have noise.

    At this point, I'm thinking it's in the power coming in to the HU. I'm not sure what else it could be, honestly. I'm also not sure what else to try.
     
  3. golkhl

    golkhl forum member

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    There is also a small factory rfi that bolts to the ignition coil bracket, any chance it could be your problem?
     
  4. joe_momma

    joe_momma forum member

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    That's the part I referenced above, someone referred to it as a "noise condenser". I bought a new one and soldered the connector from the old one on to it. No joy.

    I was doing some reading last night, and I may try a couple of things with grounds. I may try to run a ground back to the battery from the HU, or run one back to the amp (which seems like a not-so-good solution). It may be some sort of ground loop because of different grounding points. I've never had that be an issue, but it is something I can do to check. I could also try a ground-loop isolator, but I'd rather not if I don't have to.
     
  5. joe_momma

    joe_momma forum member

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    Did a little work this weekend.

    Tried the black plastic garbage bag on the back window to see if that helped with the tint removal. To my surprise, it actually loosened up the remaining tint enough for me to peel/scrape what was left of it off. It didn't go as smoothly as the videos I saw, but it at least loosened it up enough for me to get it all off. I used the bag with regular 409 cleaner. One item off the list, now I can get it scheduled for new tint. I'll be going 20% all around.

    Also messed with the radio some. I re-ran the amp ground to the rear seatbelt bolt. From my limited garage testing, it seems to have helped, although it didn't eliminate it completely. I won't know until I drive it for sure as to how much it helped. I was going to try and ground the RCA outputs to the HU chassis, but quickly got frustrated with that and gave up on it. I have some PAC ground-loop isolators on the way this week. I'll get those installed and hopefully that will take care of the rest of that issue. Driving my truck this morning ('16 F-150 Super Crew) I realized how much better my audio system is in it compared to the car. Granted, I've got much better equipment in it but the difference is staggering. I'm running JL C2 components up front - they make a ton of difference compared to the NVX budget components in the car. For the difference in price, I should have just went with those again. But, budget.
     
  6. joe_momma

    joe_momma forum member

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    I drove the car to work this morning, and the noise is improved, but not altogether gone. I can at least listen to the radio at lower levels without the noise killing it, so there's that. My ground-loop isolators should be here later this week.

    In regards to the Borlas, they are definitely more quiet than the Flowmasters. Drone is improved, but not gone. I think it may just be inherent to the exhaust system (unknown shorty headers, gutted cats, stock H). I'm not fighting that battle any longer regardless. They don't gurgle like the Flows did, which I do miss somewhat, but I think these will grow on me.
     
  7. tjm73

    tjm73 of Omicron Persei 8 S197 Team Member

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    If the drone is or gets bothersome, you could fab up a helmholz chamber to cancel it out. Someplace I have a Excel file that tells you how big the chamber has to be. If you want the file PM me and I will email it to you.
     
  8. Juice

    Juice forum member

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    For the noise, you can disable the charging system and run the engine. If the noise is gone, you have a bad diode in the alternator. If the noise is still there without the alternator charging, it is from the ignition system.
     
  9. joe_momma

    joe_momma forum member

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    How do you disable the charging system? Just unhook the power wire from the alternator? How do you isolate the ignition system, and what do you do if that's the culprit? I already replaced the noise condenser on the coil.
     
  10. Juice

    Juice forum member

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    Just unplug the small connector on the rear of the alternator. That will stop the alternator from charging. Or you can remove the belt. If the car is cold, it can run a few minutes without the belt.
    If the noise is gone with alternator disconnected, than it is ignition interference causing the hum.
     
  11. joe_momma

    joe_momma forum member

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    So the PAC ground loop isolators did nothing. Ready to torch this heap.

    EDIT: will try to check the alternator this weekend.
     
  12. joe_momma

    joe_momma forum member

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    Did a test with the alternator "off" best I can tell last night, and no change. I disconnected the large and smaller plugs on the alternator and started the car - still had the noise. I didn't disconnect the power wire that runs to the distribution block, but I don't know if that is necessary or not. I did notice that I didn't have a battery/charge light on the dash during the test, so it may have still been charging?

    I guess that's good, meaning my alternator is fine, but at the same time, I still have noise. I have one more ground to replace (the small one from the negative battery terminal to the support behind the driver headlight) but I'm not certain that is my culprit. I've got new battery terminals coming Friday, so I'll replace that when those get here.
     
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