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Discussion Starter #1
Recently picked up a 96 cobra for cheap as a new project car, but the wiring is giving me headaches and I am by far very competent with major wiring. First off the factory fan was removed and replaced with a manually controlled fan and then that was torn out and nothing was put back in, so there are currently 3 bare wires for the fan hanging out (not sure if this is at all important). So the problem is when you turn the key there is absolutely no power to anything in the interior or exterior, no lights, locks, radio, etc. The only thing that does happen when the key is turned is the ccrm clicks with every key turn and the battery light on the dash stays on. The ccrm fuse also clicks anytime I pull the eec fuse out and touch both ends. Also clicks when I touch the brake pedal when the key is off. I've checked most the grounds I believe and all the fuses look good so I'm wondering if the ccrm is shot. The battery is also good. I've been trying to find similar threads but I haven't seen the symptoms of zero power and clicking ccrm. Anyone have any input on this like I said I'm kinda out of my element here.

Also with the key on, one side of the eec fuse reads 12.4v, while the other side reads 1.2, not sure if thats a problem.
 

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King Trashmouth
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Gut feeling here is when aftermarket fan and CCRM are mentioned, I would dig deeper into whatever wiring they did.

That said, what do you have power to? Do the gauges, lights, interior, etc... function? Is it a no power condition, or a no crank/no start condition?

Does the theft light blink a code? If you don't have power to the ECM, you should get a 1-6 code for no communication.

That said, the CCRM shouldn't have anything to do with cranking. I think it's for A/C, low/high speed fans, PCM, and fuel pump. I think the crank signal is chassis side wiring.

Btw, nice A-body collection. I've got a 70 Cutlass and 68 455 Cutlass wagon myself.
 

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Discussion Starter #3
As far as wiring that's been touched I've only noticed the battery terminals have been replaced, the grounds on the rad support above the battery have been moved( there's two thicker black round wires that come from a round connector below the battery and they are both connected to the neg batttery terminal rather than the rad support which I believe is correct), and the fan wiring like I mentioned. As far as power in the interior there is absolutely nothing, the only thing that changes when I turn the ignition is the battery light comes on and the ccrm clicks. If I hit the power seat button I hear a very quiet hum but I get no response from everything else. And no cranking or any sign it can crank.
I have power to the engine fuse box but I haven't checked if it gets past that point but I'm assuming the ccrm is seeing some sort of voltage hence why it's clicking. If the ccrm doesn't send power to the Econ would that cause the no interior power condition? Or maybe I'm looking at a bad ground somewhere( I've checked the easy obvious ones).

Right on! Oldsmobiles and mustangs are an odd combo but I have a real passion for both so it's cool to find someone in the same boat!
 

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King Trashmouth
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Grounds are pretty easy to check. The main one should be from the driver's side engine mount stud to the negative terminal. I usually have a spare ground strap laying around to test things like this, and just bolt it somewhere from the engine or chassis to the negative terminal.

If you have power at the engine bay fuse box, next place I'd check is the under dash fuse panel. A couple of the fuses from the engine bay one feed that, and that's going to feed things like your ignition circuits that turn on/off a lot of accessories.

A-bodies were my first real passion. I wanted a Chevelle so bad, but I'm more than happy I ended up with a Cutlass instead. The Mustang was just a fluke I happened upon along the line.
 

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Discussion Starter #5
So got to checking the interior fuse box, I checked a couple of the main fuses and circuit breakers to see what they read with the key both on and off.
cb12(door locks, keyless entry and trunk release) - 12v key off, 1.28v key on
cb14(power windows) - 0v key off, 1.38v key on
fuse 15(cluster, chimes, cluster warning relays) - 0 key off, 2.3v key on
fuse 18(cluster, trans control module, ccrm, ignition system) - 2.3v key off, -10v key on
Im confused by all of it but especially confused by 18, why is it a negative reading and what would that mean? 18 definitely seems to be controlling a lot of the important devices. Seems like the interior fuse box doesn't have near the right voltage with the key on.
Also with the key out of the ignition if you hit the brake pedal or try moving the power seat forward or backward the battery light on the dash lights up and the ccrm clicks. Just another symptom.
 

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King Trashmouth
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I'm smelling a short or loose wire somewhere here.

What really makes me scratch my head is the negative reading. Where are you putting the ground probe on that one? On the chassis? If so, the negative would mean that your ground probe potential (voltage) is 10V higher than your power probe on the fuse. That could mean you either have a short or insufficient ground. Try measuring it with the ground probe directly on the negative terminal.
 

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Discussion Starter #7
The ground on all those was put on the dash metal frame by the fuse box but I'll run the ground out to the battery and see if I get a different reading. Thanks for the tips
 

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Discussion Starter #8
Any idea what this connector is for? It has 2 black with grey striped wires and its right next to the battery off the main harness and I didn't see anything close that would plug into it.
The last guy replaced the battery terminals so I pulled the electrical tape off both positive leads on the terminal and with no tape both wires pulled out of the crimps with a light tug. Not sure if loose crimps would cause a low voltage but I'm going to pick up some better crimps and try that also.
 

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Discussion Starter #9
So today I took off the ccrm and measured all the pins from the harness with the key both on and off.

Mustang
Pin Circuit Wire Color Application Abbreviation
1 260 R/O Power to Cooling Fan (Low Speed) PTF
2 260 R/O Power to Cooling Fan (Low Speed) PTF
3 38 BK/O B (+) to Fan Relay B (+)
4 38 BK/O B (+) to Fan Relay B (+)
5 238 DG/Y Power to Fuel Pump PTP
6 261 O/BK Power to Cooling Fan (High Speed) PTF
7 261 O/BK Power to Cooling Fan (High Speed) PTF
8 37 Y B(+) to EEC Power Relay B(+)
10 37 Y B(+) to EEC Power Relay B(+)
11 37 Y B(+) to Fuel Pump Relay B(+)
12 361 R Vehicle Power VPWR
13 16 R/LG Ignition Start/Run IGN
14 228 DB Low Speed Fan Control LFC
15 570 BK/W Power Ground PWR GND
16 57 BK A/C Clutch Ground PWR GND
17 639 LG/P High Speed Fan Control HFC
18 926 LB/O Fuel Pump Circuit FP
21 198 DG/O A/C Cycling Switch ACCS
22 331 PK/Y Wide Open Throttle A/C Cut-Off WAC
23 347 BK/Y Power to A/C Clutch Coil PTAC
24 361 R Vehicle Power VPWR

Results:
Key on/key off
1 0/0
2 0/0
3 12/12
4 12/12
5 11/.5
6 0/0
7 0/0
8 12/12
9 -
10 12/12
11 12/12
12 2.3/.1
13 12/.5
14 0/0
15 0/0
16 .1/0
17 0/0
18 0/0
19 -
20 -
21 10/.4
22 0/0
23 .1/0
24 2.3/.1

So the only things that jump out to me are prongs 12 and 24 only having 2.3v with the key on. If they send power to the pcm and its not enough to power the interior electronics that might explain some of the symptoms like the battery light coming on. Anyone have any ideas what would cause that lower volt reading?
 

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King Trashmouth
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That sounds like those pins are the input power to the CCRM, which means your problem is going to be somewhere between the fuse box and those pins, likely a bad connection or short somewhere.

Unfortunately I can't help out too much since my service manual wiring diagrams don't want to run on new software. But basically you'll need to trace that red wire and keep probing it for voltage. You might also check resistance to ground to see if there's a short.

Keep in mind the interior electronics and battery light are independent of the PCM. When I had a CCRM issue that didn't power u get a difference.the PCM, the only things I noticed was the theft light blinking and the odometer went to all dashes (not applicable in your case.) And the battery light is its own pretty simple circuit between the fuse box and the alternator.

---------- Post added at 08:52 AM ---------- Previous post was at 08:51 AM ----------

That sounds like those pins are the input power to the CCRM, which means your problem is going to be somewhere between the fuse box and those pins, likely a bad connection or short somewhere.

Unfortunately I can't help out too much since my service manual wiring diagrams don't want to run on new software. But basically you'll need to trace that red wire and keep probing it for voltage. You might also check for resistance to ground that might indicate a short.

Keep in mind the interior electronics and battery light are independent of the PCM. When I had a CCRM issue that didn't power u get a difference.the PCM, the only things I noticed was the theft light blinking and the odometer went to all dashes (not applicable in your case.) And the battery light is its own pretty simple circuit between the fuse box and the alternator.
 

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Discussion Starter #11
So sounds like I have 2 separate problems both relating from a bad ground or short that's causing low voltage. Would a bad voltage regulator or alternator cause this? I'm hoping to inspect all the wiring closely and see if I see any obvious signs of a short.
 

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Discussion Starter #13
So tonight I focused on why the battery light and only the battery light illuminated anytime something in the interior or exterior needed power. I started with this wiring diagram and the blk/org had constant 12.5v and the wht/yel and lt grn/red had 12.5v with the key on and connector unplugged. Then I plugged the alternator connector back in and remeasured all the fuses in the interior and they all checked out fine with the exception of #13 which was blown and #8 that only had 10.9 volts. I replaced both #13 and #8 fuses but then when I turned the key off, the battery light stayed illuminated and lightly pulsed which was a new thing, almost like #8 is causing a draw and turning the battery light on.

Also with alternator connector unplugged, most all the interior fuses read 12.5v, but with the connector plugged in they read 12.3. Would this be enough of a difference to set the battery light off? Otherwise I don't know what else in that circuit would cause it to turn on and off as I try to turn different things on.

Also when I put my negative end of my multimeter on the neg battery terminal/cable and the positive end of my multimeter on one of the radiator support grounds I get a reading of 10v. I tried this on my 01 and I got 0v. Now the last guy redid the grounds but he put both the smaller black ground wires that come out of the round connector below the battery and put them in with the main battery terminal. The stock routing puts one wire to the battery and the other wire to the radiator support and then a 3rd wire jumping between the 2 also acting as a ground between the radiator support and battery, now I'm wondering if I need to redo those to stock.
 

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Discussion Starter #14
It was bothering me so I ran out quick and re did the grounds and wouldn't you know the whole dash lit up and had power. I stopped there and called that a win for the night but kicking myself in the ass for not fixing that first, would have saved myself a lot of time and headache. Thanks for the help on this anyway I sure appreciate it, but I'm sure I'm a long way from having it running but I'm glad to have this figured out.
 
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