: 2002 Deville Mechanics are stumped



soccer_eldorado
03-24-11, 08:25 PM
I posted on here about my 02 Deville losing all power both electrical and mechanical on the freeway. I changed the battery (which there was a lot of corrosion on the positive post), cleaned the positive battery cable, and still nothing, no locks, windows, any power accessories, nothing. I had it towed to the mechanic shop, they've had it two days, and they can't find anything, totally stumped. I hate the idea of taking the car to a dealer for some colossal fee, especially when I am used to fixing my own cars with years of being able to fix anything that happened. They put a jumper on the front contacts in the engine bay, and on the actual battery under the back seat, an still nothing. I'm wondering if its possibly the positive battery cable that goes under the car floorboard that might have had a short in it, or the PCM. Any thoughts? I'm totally stumped.

JimD
03-24-11, 09:25 PM
I posted on here about my 02 Deville losing all power both electrical and mechanical on the freeway. I changed the battery (which there was a lot of corrosion on the positive post), cleaned the positive battery cable, and still nothing, no locks, windows, any power accessories, nothing.Stop right there.

"A lot of corrosion on the positive post" means your original battery case was cracked OR the vent tubes were not connected properly. Corrosion at that point in your year/model means acid or acidic fumes are/were present.

Cleaning the cable terminals might not be solve the potential problem. What I would do is disconnect both battery cables and open the insulation looking for evidence of corrosion/oxidation on the surface of the wires, starting at the battery cable end connector.

If you, or whoever you hire, is not comfortable slicing open the insulation on a high current cable, find someone who knows what they are doing.

mhamilton
03-24-11, 09:28 PM
This shouldn't take a dealer to diagnose... if you have the wiring diagram for the ignition switch, you can easily check with a test light to see if the switch is getting 12v, and if not, trace back to where it is. Since you are getting nothing (no security light, etc) it sounds like it's a main 12v supply wire. I don't know how the main battery wires are routed on your Seville, but it could be broken. It wouldn't be a short, that would cause arcing as soon as it was connected to the battery.

jimsbox
03-24-11, 10:22 PM
I wouldn't get to focused on the red 12 volt side of the equation, you can have the same problem with a bad ground side connection. May be at the battery or may be from the chassis just behind the rt headlight to the engine just above the alternator.

Ranger
03-24-11, 11:31 PM
Cleaning the cable terminals might not be solve the potential problem. What I would do is disconnect both battery cables and open the insulation looking for evidence of corrosion/oxidation on the surface of the wires, starting at the battery cable end connector.
Been there before and well worth checking into. In a bad situation corrosion can get under the cable insulation.


"A lot of corrosion on the positive post" means your original battery case was cracked OR the vent tubes were not connected properly. Corrosion at that point in your year/model means acid or acidic fumes are/were present.
Remember, your fuse box is under the seat as well and if Jim's assumption is correct, it would be well worth your or your mechanics time to check out the fuse box and connections.

soccer_eldorado
03-25-11, 08:40 AM
The Mechanic said they went over all the fuses and connections, and they still can't find it. I'm hearing what all you guys are saying, but I would thing they've checked all of that. I have to wait until Saturday to actually go and get the car towed home as I'm at work until the shop actually closes. Speaking of the cleaning the terminals not being the end all say all, they cable connector itself looked almost like it had rust, to where no amount of cleaning (and I did a lot) made it shiny silver like a positive battery cable should look like (under the insulation). I'm leaning toward ordering a new positive battery cable and installing it when it arrives. As far as the negative battery cable goes, those are cheap, and easy to replace, so I'll probably do that as well.

00 Deville
03-25-11, 09:28 AM
Did you check to see if the battery vent tubes are hooked up as JimD suggested in post #2... you do have the group 79 battery with the external vent tube connections.... don't you.

soccer_eldorado
03-25-11, 01:15 PM
When I get the car back I will check. Based on everyone's response, the one that seems apparent is that there is corrosion within the insulation. I haven't cut it open yet, but it appeared that this was the case the last time I saw the cable/battery. How do I replace the positive battery cable? It looks like it goes under the floorboard up to the front of the car, how would I access it? I was thinking I could possibly fasten the new cable to the old, and then pull the old cable out the front, pulling the new cable with it, but I'm guessing there's probably fasteners under the floorboard that would make this task unfeasible.

postman2000
03-25-11, 04:55 PM
I had a similar problem on my 2000 deville.. Car was completely dead. The ground strap/wire that connects near alternator had broken do to being over extended by the front motor mount being bad. What i did was i put a set of jumper cables to both strut towers and to 2 places on the engine.. The engine fired right up. Took off the jumper cables and completely dead. What i did was just make my own grounds, I put one from the left strut tower to a bolt near the water pump and the right strut tower to a plate that on the 93-98 northstars actually was the ground..Been driving for 2 years like that no problem. I had replaced some much stuff on this car that when that happened i just took the lazy way out...

jimsbox
03-25-11, 05:05 PM
That is what I was talking about previously, goes from above the alternator to the chassis right behind the headlight. I also had to do the same thing using 4 ga. straps.

johnny kannapo
03-25-11, 07:38 PM
This shouldn't take a dealer to diagnose... if you have the wiring diagram for the ignition switch, you can easily check with a test light to see if the switch is getting 12v, and if not, trace back to where it is. Since you are getting nothing (no security light, etc) it sounds like it's a main 12v supply wire. I don't know how the main battery wires are routed on your Seville, but it could be broken. It wouldn't be a short, that would cause arcing as soon as it was connected to the battery.

A test light won't show 12 volts, it only lights up. It will light up with 3 volts.

Use a VOM

The acid will leech down the cable into the strands, look for areas on the cable that appear swollen, this could happen several inches down & this would be an indication acid is burning away the cable in that area underneath the plastic insulation.

If you have low current a simple load draw can kill all power leave you stranded by doing something like pushing the brake lights on or the radiator fan kicking on.

The PCM needs 11 or 12 volts minimum everything shuts down. Look over that smaller red cable, that powers the PCM which is everything. The neg. and grounds may be a problem.

postman2000
03-25-11, 08:17 PM
Yes Jim.. Thats the one.. Seems to be a subsequent problem to the engine mount going bad.. These cars have their fair share of problems, but atleast they all seem to have the same problems.. They usually dont stray from the normal things like ..Head Gaskets, Window regulators, Ground Straps, EGR Valves, Motor mounts ..etc...They definitely are a labor of love.. But i think their styling and performance is the best bang for the buck..

soccer_eldorado
03-26-11, 12:02 PM
Postman, I agree, the cadillac always has me coming back to buy another one every couple of years, and the Lincolns, they do have their problems, it just seems like its never that big of a deal to fix them. I have a mint condition 94 Continental (Yes, I know the P.O.S. 3.8 liter V6, but teh car is truely a pleasure to drive, and very easy to fix), and a 96 town car (extremely smooth ride, but hte AC never was quite cold enough), and I've had it 10 years, hardly every gave me trouble.

smooththg6969
03-28-11, 06:09 PM
where in miami are you located? I might be able to come take a look at it if your not too far from me.

soccer_eldorado
03-30-11, 07:34 PM
I live in Miami Shores. The mechanics today said that hte ignition switch fuse was to blame. They put in a new fuse, let the car idle for 15 minutes, and the car was fine, and then they drove 30 feet, and the fuse blew again, and then they put in another fuse, and said nothing blew. Do you guys think the ignition switch is to blame? They said they'd be just guessing if they put in a new ignition switch. What do you guys think?

Submariner409
03-31-11, 08:16 AM
Post #15 is identical to another thread you just started.....:sneaky:

Nowhere in this thread does it appear that you have queried the car's built-in DTC (Diagnostic Trouble Code) system to see if it has logged any electrical faults. Those IGN fuses feed a LOT of systems and modules.

ThumperPup
03-31-11, 09:16 AM
Post #15 is identical to another thread you just started.....:sneaky:

Nowhere in this thread does it appear that you have queried the car's built-in DTC (Diagnostic Trouble Code) system to see if it has logged any electrical faults. Those IGN fuses feed a LOT of systems and modules.

now that the op can get power then yes he should check the DTC and pull codes see what it says
but before he could not because he had no power going to the car at all no way to check the DTC
also woudl the DTC even have codes in it about this issue if there was no power to the system ?