Cleaning PCM and connections
Thread Starter
Instructor
Joined: Oct 2005
Posts: 150
Likes: 0
From: Wisconsin
Cleaning PCM and connections
I pulled the battery and battery mounting and found that the PCM is covered with a white fuzzy substance like you would get on the posts of the old style top mount battery. The wires look good and show no signs of battery acid. I have a problem with a cooling fan motor not getting power is why I have pulled all of this out. How do I clean this area. Do I remove the PCM or leave it installed and clean with Simply green and low pressure water or WD40? Thanks 
Thread Starter
Instructor
Joined: Oct 2005
Posts: 150
Likes: 0
From: Wisconsin
Originally Posted by Hoichi
You might want to pm Bill Curlee. He is the electrical guru.....he wrote the thread on grounds. I am sure he will know the answer.
Racer
Joined: Jan 2006
Posts: 479
Likes: 2
From: Hollywood Maryland
Cleaning the PCM area
I bought a used '99 FRC in which the previous owner ( lease) hardly maintained the car. It had the dreaded battery leak/destroyed HVAC vacum lines issue. I pulled the passenger wheel well access panel and saw the same things you did around my PCM. I also had acid damage all over the area below the battery. I decided to pull the passenger fender and then the PCM to clean/paint the area so it looks new. I used a spray battery CLEANER (not battery protector sealant) versus baking soda and water. You can get these at Advanced Auto, Auto Zone etc. It foams up and nuetralizes any acid and is minimally messy. I then cleaned the case of the PCM, its mounting bracket, and frame area behind the PCM bracket. There was no visible damage to the PCM case from battery acid. I polished the cover, remounted the PCM, cleaned the connectors using CRC electrical contact cleaner and hooked it up. I also used the battery cleaner foam through out the area under the battery. Put every thing back together and it started right up, no problems. Pullintg the fender may be a bit radical, but it gave me an unemcumbered view of the area. You can just loosen the fender by removing a bolt on the bottom under the passenger area and a bolt that's inside the middle of the fender area looking back. It's about in the middle and hard to see. Loosen the top fender bolts and you can easily pry the fender outwards to get to the PCM. Good luck.
Advanced
Joined: Jan 2006
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From: Winnipeg MB.
Safety Car
Joined: Jun 2004
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From: panama city beach florida USA
St. Jude Donor '09
as far as the acid dust i would air blow it away. if ya put water only yer gonna make flowing acid. look to fix fan first if its because of batt droppings then clean with baking soda and water. i need more info on fan . will it work if ya put a/c on ? 2or3 relays in under hood elect center for fans . swap them around. the fuel inj. relay i believe is the same. check the fuses there with a volt meter no test light. dont start disconnecting ecm ,s yet ya can make more problems
