Taurus Car Club of America : Ford Taurus Forum banner

1 - 20 of 57 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter #1 (Edited)
Audiophile/electrician needed!

Gentlemen and Ladies, thanks for considering my problem.

I'll try to be brief, but thorough. I've searched the internet for countless hours, but none of the suggested solutions seem to fix my dilemma.

History:
I have a 2006 3.0L Vulcan SE. Been driving it for about 4 years. Great car. I keep up on all recommended maintenance. It's at around 105k miles, currently. Everything appears to be OEM, other than standard maintenance replacements like tires and brakes, etc. Standard RCU (non-Mach). I rarely, turn the volume past halfway and typically around 3 to 4 notches on the display.

Everything has been running perfectly all these years... until recently...

Problem:
Over the last several weeks my speakers have started to cut out intermittently. All sound just stops for a second and comes back. This occurs on all sources (FM, AM, CD). Nothing else cuts out; all display lights stay on.

It never does it while sitting still. Whether the engine is running or on Acc power, the speakers continue without interruption. It only seems to occur after I've been driving several minutes and even then, only once I get up to 50mph or above. Hitting bumps do NOT seem to affect whether or not it occurs. Dropping below 50mph seems to "fix" it.

Weird, huh? :huh:

Although, it has happened maybe once or twice below 50mph, but only in the last few days. Problem getting worse? Hot weather, perhaps? Also, a week or so ago, the weather got considerably cooler and I did not observe any cut-outs on that day. Fluke? Or pertinent?

What I've tried so far:
Pulled the door panels and looked at all the wiring. Connections to speakers are well designed and I don't see how any wires might be shorting to ground, unless I overlooked something. I have a printout of the wiring diagram from the wiki.

Jiggled wire harness in multiple places. Tapped on various body panels, door panels, dash, etc., but could not replicate problem. Pulled the ICP in the dash and reseated connections. Lots of jiggling of wires, but never once made the speakers cut out.

Took my multimeter to the back of the RCU and checked voltage to power wire. On Acc (engine off, radio on), I'm getting 12.4 volts. With engine running, voltage goes up into the 13s (forgot to note exact #). Is there something else I should be metering for? Will it only show while the speakers actually cut out?

Then, I acquired a MACH RCU with tweeters and installed. Still the same exact problem so bad RCU wasn't causing it. At the same time, I sanded and smoothed the body grounds for the battery to chassis and in the trunk for the black/green RCU ground to chassis. Also applied dielectric grease. Also, cleaned both positive and negative battery terminals. Battery is less than a year old.

Summary/discussion:
After several years of perfect performance, speakers are cutting out only above 50mph. Unaffected by bumps. Still occurring after replacing amp. The usual internet suggestions haven't helped.

Could it be weather related? As best as I can tell it has seemed to have started with the increase in summer temperature. I can't be certain of that, though, because the temp hasn't fallen low enough or often enough to make anything more than an assumption.

I'm not a rich man, but I am well versed in turning wrenches so it seems silly to pay someone money to fix a problem that I'm capable of doing, myself. I just need to know what the cause of the problem is so I can repair it. Can anyone help me?

Thanks and regards,
-Patrick
 

·
Registered
Joined
·
33 Posts
Discussion Starter #2 (Edited)
Another thing I'm wondering is if doing the "Big 3" would fix the problem. I'm trying to determine how everything would be fine for so long then start getting worse one summer, then it occurred to me that perhaps there are some bad connections "forming" in the charging system engine compartment. So, instead of removing and cleaning all those other connections, maybe I should just do the "Big 3."

Anyone with electronics troubleshooting skills?

-Patrick
 

·
Registered
Joined
·
33 Posts
Discussion Starter #3
Also done:
Today I pulled, cleaned, and checked connection of antenna at both ends. Pulled the ICP again and checked some voltages with the engine off and radio on. Assuming the wiki wiring diagram color codes are still the same, the "audio system on" measured just above 11 volts, the red/yell "fused ignition" measured barely 12.10 volts and the blk/pink "fused ignition" measured same. I also checked the black ground wire and got zero resistance to chassis ground.

The "audio on" was almost a volt lower than battery voltage. Is that significant?

Does that help? Should I pull the door panels again? and double check for possible ground shorts? If so, would that coincide with speakers cutting out above 50mph?
 

·
Registered
Joined
·
33 Posts
Discussion Starter #4
Bump. Any expert electricians or audiophiles?

Today I measured some resistances in my power cables. From battery (-) to chassis I get over 1ohm from the battery post to the copper wire and another half an ohm or more to the chassis. I measured similar on the positive terminal. Is this as expected? I'm running out of options and happen to have the day off so might spring for the Big 3 upgrade.
 

·
Registered
Joined
·
33 Posts
Discussion Starter #5
Wow. The more I search, the more overwhelmed I feel. Thank goodness for forums full of experts like this one!

After further poking and prodding of the search function here, I'm seeing mention of a relation between the radio cutting out and the Transmission Range Sensor. I found a wiring diagram specific to my 2006 and I see something called a "Digital Transmission Range Sensor" in the wiring loop for the audio system. Posts regarding problems with the radio connected to the TRS all seem to be older generations. Also, they all mention repeatable issues like no radio in reverse or similar and problems shifting and/or power steering.

However, my power steering and shifting are all buttery smooth. So, is the TRS something I should take a look at with the 2006? Or was that a 1996 problem?
 

·
Registered
Joined
·
221 Posts
When the sound cuts out is it in all speakers?
I dont think big 3 would help at all, the stereo doesnt flicker right? it holds power and light when the sound cuts
The mach system pulls very little power no need to upgrade wiring but you might find something coroded or loose
 

·
Premium Member
Joined
·
449 Posts
I would say leave your door panels alone, focus on the rcu... I would suggest installing a light inline between the rcu's power and ground and install another light between the "SYSOn" wire and the ground and route both of the lights to right on top of the dash and when you have the issue see if one light is out and figure out what the RCU is missing... On side note Big3 is for when you run an aftermarket amp and a very big one at that... Your don't need to fool with that...
 

·
Registered
Joined
·
33 Posts
Discussion Starter #8
When the sound cuts out is it in all speakers?
I dont think big 3 would help at all, the stereo doesnt flicker right? it holds power and light when the sound cuts
The mach system pulls very little power no need to upgrade wiring but you might find something coroded or loose
Yessir, the sound cuts out on all speakers and nothing flickers. Does this suggest it's not a wiring problem? Or, at least, not a power problem.
 

·
Registered
Joined
·
33 Posts
Discussion Starter #9
I would say leave your door panels alone, focus on the rcu... I would suggest installing a light inline between the rcu's power and ground and install another light between the "SYSOn" wire and the ground and route both of the lights to right on top of the dash and when you have the issue see if one light is out and figure out what the RCU is missing... On side note Big3 is for when you run an aftermarket amp and a very big one at that... Your don't need to fool with that...
Great idea. I've been trying to think of a way to hook up my DMM so I can check it while driving, but had no idea which wires to connect to. That or I can have a friend hang out in the trunk and check while I drive. Kidding, of course.

If you think it's likely one of those wires causing the problem then I will try that.

Thanks!
 

·
Registered
Joined
·
221 Posts
all speakers cutting out would narrow it down quite a bit, so im thinking from the deck to the rcu is ok, wires from rcu to speakers is ok, looks like your stuck in the middle somewhere lol probably rcu like xman says

You say you changed rcu and still same problem? maybe power line for rcu to wherever it gets power from, is the rcu actually grounded to metal with screws? might try that too
 

·
Registered
Joined
·
1,923 Posts
I am not a stock audio guy. It does appear you covered the bases that I would have. The first thing I did after I bought my car was to remove all stock audio conponents. The big 3 isn't the issue. Its sounds like an rcu issue but that is a possibility you will have to confirm.

If you had an aftermarket head unit I would have assumed a short in the door panels which I have experienced in the past and it does mimic the problem your currently having. If you do ever decide to go the aftermarket route. You should run new 16ga wire to and protect the speaker wires with loom and electrical tape to prevent shorts later on. Also doing the big 3 in 4 ga even with no system can benefit your car in over 5 ways especially in the winter. (0/1 gauge) for the big 3 IF you install a system over 1,500 watts.

Good luck on the multimeter short/ non continuity hunt.
 

·
Premium Member
Joined
·
449 Posts
You'll have to splice into the power,ground and SYSON wire at the rcu and run some automotive with to a small like the is in view of the driver...

Great idea. I've been trying to think of a way to hook up my DMM so I can check it while driving, but had no idea which wires to connect to. That or I can have a friend hang out in the trunk and check while I drive. Kidding, of course.

If you think it's likely one of those wires causing the problem then I will try that.

Thanks!
 

·
Registered
Joined
·
33 Posts
Discussion Starter #13
So you think I should splice in immediately after the RCU or further up towards the ICP, especially the SYSON?

I did replace the RCU and the exact same problem is occurring. It's so weird because cut-outs above 50 almost sound kinda-sorta like a TRS thing, but shifting and all other electronics are buttery smooth. I simply can't warrant spending money on an aftermarket system, but darn tootin' if I do decide that, I'll install it all myself!

I want you guys to know that I appreciate you taking the time to consider my problem. I'll update if I ever solve it in case it helps someone else.
 

·
Registered
Joined
·
33 Posts
Discussion Starter #14
I'm still leaning toward some sort of corrosion related issue due to the fact that it's been perfect all these years with no changes in the system. As a further update, I did pull, clean, and grease all related fuses. They were, indeed, quite dirty. I haven't had a change to test it, yet.
 

·
Registered
Joined
·
221 Posts
I think i remember a problem similar to that and thought i fixed it by grounding the rcu chassis to the body of the car, sand down the metal a bit where its going to contact and actually mount it with screws, cant hurt and shouldnt take that long. Im a little lost on what the other members are saying its being a long time since i messed with the mach

Oh ya make sure it sits flush against the body of the car so the chassis of the mach is not being twisted when you screw down the screws
 

·
Registered
Joined
·
33 Posts
Discussion Starter #16
Not sure if this helps troubleshoot the problem for anyone willing to help; this morning I had to take my dogs to the vet, but never had radio on. Engine was completely warmed up by the time I dropped dogs off at home. When I got back in the car to go to work I turned the radio on and the speakers were cutting out randomly. Engine was on, transmission in park. I immediately jumped out and grabbed my DMM, but the time I got into the trunk and unmounted the RCU to start metering points the speakers never cut out again. I waited a while, but no dice. I did measure 13.8 volts on the main power and only 12.8 on the SYSON line. It's 13.8 when NOT connected to the RCU, though.

UGH!! but at least I know the problem is not exclusive to over 50mph (just a whole lot less often). Rather, it only starts doing it when the car is well warmed up...apparently. And even then, I think it's only occurring when the engine is actually running (not on acc power).

I think i remember a problem similar to that and thought i fixed it by grounding the rcu chassis to the body of the car, sand down the metal a bit where its going to contact and actually mount it with screws,...
You mean ground the case of the RCU or the mounting frame? I measured zero resistance from RCU case to car chassis ground. The ground for the RCU harness was cleaned and sanded previously so it should be a good ground. Nonetheless, I did attach at wire from the RCU case to car chassis ground as you suggested , but my commute to work this morning indicates I have NOT yet fixed the problem.

Think I'll stop at a parts store on the way home and buy a couple small taillight bulbs or something to try the test-light trick xmanglc suggests.
 

·
Registered
Joined
·
33 Posts
Discussion Starter #17
Another thought:

when troubleshooting a problem we know we should first consider what, if anything, has changed. Well, other than the hot weather, I did recently change my transmission fluid and filter. I was very careful to keep it clean under there, but is there any chance a small particle got in there and is somehow affecting the TRS just right to cause this problem? Shifting the lever does NOT affect speakers, though.

Not likely the cause, right?
 

·
Registered
Joined
·
221 Posts
ya the case of the rcu, i remember something weird about the ground, i think there is 2 ground wires on that amp and at least one of them wasnt black. But ya if thats ok maybe something shorting or the +ve power wire for the amp is loose somewhere. Do you need any wiring schematics? I could find those. gl;)
 

·
Registered
Joined
·
221 Posts
Another thought:

when troubleshooting a problem we know we should first consider what, if anything, has changed. Well, other than the hot weather, I did recently change my transmission fluid and filter. I was very careful to keep it clean under there, but is there any chance a small particle got in there and is somehow affecting the TRS just right to cause this problem? Shifting the lever does NOT affect speakers, though.

Not likely the cause, right?
I dont think that sensor is anyhow connected to the mach system, do you have any audio wires running through the shifter?
But you did say you installed tweeters, did this problem start after that?
 

·
Registered
Joined
·
33 Posts
Discussion Starter #20
ya the case of the rcu, i remember something weird about the ground, i think there is 2 ground wires on that amp and at least one of them wasnt black. But ya if thats ok maybe something shorting or the +ve power wire for the amp is loose somewhere. Do you need any wiring schematics? I could find those. gl;)
I have wiring schematics. Thanks, though! I don't see +ve in the schematics, though. That's main power?

At this point, I think I need to make an extended lead for my DMM and start metering both ends of all the wires so I can check for shorts the right way. Also sounds like maybe I should trace the power and SYSON wires through every nook and cranny.

I WILL solve this problem somehow!!
 
1 - 20 of 57 Posts
Top