I just bought a '99 convertible. The A/C stopped working and I took it in for service. They just told me that battery acid leaked on the PCM / harness and it's going to cost $6000 to fix it!! I only paid $21,000 and cant afford another 6G's. Any advice?

 

PM sent.

 

Holy **** Batman, Six Grand Get another repair quote. Have you talk to the person/dealer you purchased it from? (lemon law)

 

I assume you took it in to a Dealership (i.e. Stealership). Thank them (and pay them) for their diagnosis and get it out of there!

Search for fixes. You must remove battery, use a lot of baking soda and water, they have acid cleaner/detecter, use it. You must remove and clean connectors. Also will need to paint. Some vacuum lines are bad (this affects your HVAC). Other people have fixed this.

Replace battery with an AGM (non-leaking battery) like an Optima, Excide Orbital, Sears Platinum.

Check your codes from the DIC (search for how to do this).

Good luck !

 

Thanks for the advice...and yes it was a dealer. My current battery is new. Apparently the leak happened a while ago. The dealer said the harness is bad and it's going to cost 2700 for the part and 20 hours of labor. I would love to take the time to do this job myself, but I'm in F-16 training right now (hence viperdriver...not the dodge) and have no time. How much does this usually cost if I find a reputable mechanic?

 

What kind of battery is it?

 

I have heard this and the same price quote TWO times. Run forest,,,,,Run as fast as you can!!!!!!!! I helped LVVETTE fix his $6000 dealer estimated damage for less than $100. PM him for the exact details! He will be more than happy to talk to you about it!

This is fixable and you can do it your self! The very first thing that you need to do is neutralize the remaining acid and acid residue. You can use a baking soda/water mixture or a spray can of battery acid neutralizer. Once the acid has been neutralized, you can start the repair process.

It consist of inspecting the wiring harnesses, connectors, and electrical components and repairing any damaged wiring and electrical components. The PCM needs to be removed and the outer aluminum case needs to be inspected and sealed if it is corroding.

Then you will need to repair the metal frame finish. Sand off any corrosion, use a rust converter, and repaint the frame.

Inspect ALL vacuum lines and vacuum components. If your HVAC vent ducting fails to be switchable, it caused by vacuum line acid damage.

There is a ground splice pack in the behind the battery that needs to be inspected and cleaned. If it was exposed to acid or acid fumes, this is what happens:



If you have specific questions, you can PM Me!

BC

 

Heres a post to an EXCELLENT write up on a battery acid leak post. My buddy MR1911 has the repair DOWN PAT!!!!!! Take a look at the post for some great details:

http://forums.corvetteforum.com/show...post1562589976

There are a couple of Excellent C5 shops near you, Contact CAJUNDUDE (Jason ) of Gulf Coast Performance! He does EXCELLENT work and will work with you!!!!!! His shop is in Huston TX but for excellent work, it isn't that far! Give him a call.

www.gulfcoastperformance.com

Bill C

 

Bill knows his stuff!
Aare you having any other problems, other than the AC? I'm curious as to how they KNOW the PCM and wiring are toast. I'd do some more research if I were you. Either that, or take it to Cajun and have him take a look at it.
Either way, make sure you get that acid neutralized and FAST, before it really does mess something up.
Good luck and keep us posted.

 

Sneakelnan is correct in asking what other issues that your seeing other than the AC issue. If just the AC is having issues, please explain what issues your having with it.


If you can, please read and post the DTCs that are stored in the DIC that will give us a wealth of info. It is possible that the STEALERSHIP could be blowing smoke and there is something entirely different wrong. Thats where reading the DTCs and providing us some more info on the AC NOT WORKING statement will help us give you a fix or help us help you make a decision on what you should do.

Here are some directions on reading DTCs and a website on DTC Code information.

These are the absolute best C5 Diagnostic Trouble Code (DTC) web sites!!!

http://www.corvettedoctor.com/Code_Main.html
http://www.corvettedoctor.com/index.html


Go to “technical data base” and then to “Corvette ECM Computer Codes”. Then select your year car. Read the instructions and then scroll down to the "READ MORE" window to view the code definitions.\

Here is another very good site:

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix!!


The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.

Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes)
If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, C or ;H. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present;
press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET
To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.





Bill

 

Mike

If somone sold you the Vette with that problem I'd be dropping him a call. You don't get a battery leak and fit a new battery without knowing that it leaked

Its going to be a lot easier getting through Viper conversion than fixing that problem.

Bill Curlee is the Forum electrical guru so you're getting the best advice out there

.......Even if he is ex Navy

 

Wow, I'm impressed. Thanks for all the help guys.

I took everyones advice and ran from the dealership. I just pulled the battery to take a look. I can see some external rust but nothing terrible. It looks like I need to pull off the side fender to get a good look at the PCM and the wire harness. I'll try that this saturday. So far all i did was spread baking soda and water around the area under the battery.

As far as symptoms... Originally, my A/C would blow cold air on one side and hot air on the other. If I shut off the car and turned it back on sometimes I would have both cold. The air would change from defog, center, and foot vents just fine, but the temperature would not adjust properly. I can also hear a noise sounding like a worn out electric motor running under the dash on the right side of the center vent. (where the right temperature actuator is located). I pulled the codes a while back and it said "right actuator short to ground" and "right actuator open". Soon after the fan stopped working too. I had to adjust the fan up and down repeatedly and it would finally kick on. Now... I can still hear the noise, the HVAC is stuck on hot, and the fan does not work. engine runs great and no other codes, just the HVAC problems.

 

Viper, you're having the EXACT same problems I'm having right now. And I KNOW my PCM is fine. My drivers side actuator is the one giving me problems. I have the new part, came today, and will be installing it tomorrow, or at the latest this weekend. I'll let you know how things come out. Hang on a bit until I get this finished. Of course, I also have a new HVAC control unit to go in also. But, I'm going to do the actuator first, as I'm 99% sure that is what is causing the entire problem.
Just sit tight for a day or so, and I may have the answer to your problems for you.

 

You said you just bought the car so, once again, did you get it from a dealer, in which case you may have some recourse, or from a private party?

 

Instead of removing the fender, there is an access panel in the passengers and driver side fender wells that will allow you access to the inner fender well.



You can get to the PCM, TAC module and access the vacuum stuff via that access. When you put baking soda on the area, if it foams there was some sort of acidic substance on the surface. Acid when evaporates on plastic and some metal surfaces is a white powdery residue.

As for your HVAC issue, try this:

Turn the HVAC system OFF.
Bring up the Diagnostic routine in the DIC and go straight into MANUAL MODE and scroll down to HVAC and clear all the set DTC. Once their clear, you will hear the actuator motors cycle.

Once they stop cycling, turn the HVAC unit ON and see if it works normally and if it causes any more DTCs to set.

My HVAC gave me fits (same symptoms) not long ago while I was on a long trip and I did some troubleshooting on the road and used this procedure and now its working great. Had to do it a couple of times before it worked correctly. Just something to try that might give us some more info.

As for your FAN issue, there are a couple of things this could be. I'm out of town and don't have access to my manuals so,,,,if you you can wait till Sunday or if someone else can chime in, Do you have DUEL CLIMATE CONTROL or MANUAL controls on your HVAC control panel??
Need that info to give you the correct information.

BC

 

Viper,
Got the new actuator put in just now, in a nice warm heated garage. Thanks John!
It fixed ALL problems! Heat, AC, and fan work as normal again. Took apart old one, and the main gear was cracked in half. That was what was causing the problems.
Run like hell from the dealership! Replace your bad actuator, and all should be well again. Unfortunately for you, you are going to have to pull the dash pad off to replace the passenger actuator. I was lucky enough to be able to lay on the drivers side floorboard and get to the left side one.
Let me know how things go bud.

 

Had air blowing out of all vents for several years. Found the battery acid problem on here. If car is running RIGHT the PCM is probably fine.
My wires sizzled like crazy when I used baking soda. Take out the battery tray by taking out the battery and removing 4 bolts holding the tray on. THEN use PLEANTY of baking soda and apply it ALL OVER EVERYTHING on the right side of the car. I had to undo some of the wiring harness to FIND the vacuum source. There is my post on here and lots more showing you how to fix this. Don't skimp on the vacuum line. I replaced only a few inches and a week later had no vacuum again. Replaced most of the supply line down to the check valve (which was also bad...a new one is at Advance Auto for $3.48 not $6 plus for the same part at the stealership). Left enough to let the original ends go into the check valve which is just inside the passanger fender and the lead going thru the firewall ending in a purple connector.
You might have bad actuators or MIGHT NOT. If there is no vacuum all you get is a mixture of EVERYTHING hot and cold and inside air and outside air. Recharged my AC recently because it wasn't cooling right. The damn check valve cracked again caused a similar problem.
Do it yourself and save a bundle. BIGHANK

 

I've had my Z for 3 weeks now. When I finished reading this thread I called the part store and ordered a gell cell battery. It will be there first thing in the morning.

 

Good idea SS! Even if it isn't leaking(like mine wasn't) the post can come out without warning and wreak havoc!

 

I had a lot of battery damage on my used FRC when I bought it. Frame corrosion, vacumn lines obliterated, acid on PCM cover etc. I decided to tackle all issues by removing the fender and having non restricted access to the whole area around and under the battery. I pulled the PCM and cleaned the case with CRC Battery cleaner (Find at your local auto parts store)which is a foaming product and is a lot less messy than baking soda and water. Has the same effect. I pulled the battery, battery stand, PCM, and PCM bracket. Sprayed the whole area with Battery cleaner including all wiring harnesses. Degreased everything, lightly sanded any corrosion damage, primed and painted areas damaged by the leaky battery. I used CRC Electronic Contact spray and sprayed the PCM Contacts and wiring harness contacts. Examined the PCM Wiring for any damage, there was none. Sprayed all wiring under the battery area with the CRC Battery Cleaner, used degreaser and soap and water. Reinstalled the PCM. Reconnected it. Started the car to make sure no codes. All OK. Found the damaged vacumn lines. Cut back the source line until I had good line and spliced in new line using 1/8" emissions hose and splices from the local auto parts store. Did the same for the supply line that goes to the large grommet on the firewall behind the battery. Before connecting the source and supply lines to the vacumn cannister near the passenger door, I encased the vacumn lines with 1/4" ID Rubber Fuel line in the battery area. No more worries about battery acid damaging vacumn lines. The fuel line hose is almost indestructable. While I had the fender off I changed out the vacumn cannister check valve (Get from dealer, it's cheap). I tested the HVAC operation before putting the fender back on. All worked fine. Cleaned the fender inside, access cover and reinstalled. Everything is still working a year later. Also switched to an Optima Red Top battery. You don't have to remove the fender, but I wanted to see all the damage and fix it. If you just remove the access panel, it's a lot easier if you lossen the bottom of the fender to swing it out away from the PCM and vacumn canister. Its an easy DIYer. And yes, I'd stay away from that dealer. If the car's not under warranty, then as suggested go to a good 'Vette shop and create a lasting relationship. This is a Corvette not a Cobalt. Dealers are pretty much useless with Corvettes unless they have a Corvette savvy reputation. Good luck. DON'T FORGET TO DISCONNECT YOUR BATTERY PRIOR TO REMOVING THE PCM CONNECTORS OR CONNECTING THEM!!!!!!