RMCIII 838 #1 Posted November 25, 2014 So Friday, it was still moderately chilly, 22 degrees, here in Cleveland. I go out to the garage and start the Jeep up to warm up. 1998 Jeep Grand Cherokee - 5.9L. Only made the 1 year. I'm not the original owner, (2nd.) but well taken care of... It has the Automatic Air Condition Control unit. Anyway, I come out after about 15 minutes, open the door, and smoke rolls out of the cab. It smells of burnt electrical. I also notice no fan is blowing. I shut the heater off. I check it over, to make sure, nothing is still burning. I can't see anything, but it smells horrible. I take it work anyway. No heat in 22 degree weather, driving 70mph, has a way to chill a person. Hands were almost numb. Would have taken the Tahoe, but the wife needed to run some errands. That night my neighbor and I dive into what we think is the fan. We remove the fan. Looks fine, no burnt wires. We look a little further and notice, on the wire connector to a AACC unit, the black wire looks a little melted. We dig a little further. Hmmm, unit won't come out, after removing the 3 bolts that hold it in place. We remove part of the interior fuse panel to create a pry point, for a screw driver, to be used to pry it out. When we finally get it out, we see the issue. The entire side, that has a connector, is completely melted. It had fused itself to he firewall. The connector was fused into the unit. I decide to take it apart and see just how bad the internals are. Can you say mother board FRIED! I was able to pry the opposite side open, when I did, it cracked the melted side, no worries it is no good anyway. The mother board, all resisters, diodes, and a few other smaller components were burned beyond recognition. Several of the components just fell off the board. My neighbor and I looked at each stunned. We looked at the inside top of the cap, it was melted on the upper inside also, it just had not made it through the top side of the cap.... This thing was seconds from igniting that whole unit on fire. No telling if it would have burned itself out before catching the whole Jeep on fire, or what. Today Jeep is running fine, got a new/used component. Electrical is a funny thing. Even new parts can sometimes be bad, so I chose to go the cheaper route. Not sure that was the best decision, but I can say, the AACC unit is working better than before. Now when you select Lo or Hi auto, the fan speed actually is on a Lo or Hi speed. It had not been that way in a while. I just chalked it up to the fan going bad. Had no idea the Jeep even had a module of that sort buried up under the passenger dash board. God is good. It was not luck that kept the Jeep from burning up. Rob Share this post Link to post Share on other sites
squonk 43,735 #2 Posted November 25, 2014 I'm thinking the resistors that control the fan speeds went bad and finallythings got hot enough to start melting away. I have seen tons of melted fan resistor blocks, connector plugs ect for blower fans on all makes and models. lots of amperage there. Usually the connector gets warm, the terminals get weak and lose connection and up goes the amps until POOF! 1 Share this post Link to post Share on other sites
RMCIII 838 #3 Posted November 25, 2014 (edited) You are correct about the amperage.. It has a smaller 15amp on the inside fuse panel and a much larger 40amp under the hood of the Jeep. But the strange thing about it was, neither fuse was blown...... Rob Edited November 25, 2014 by RMCIII Share this post Link to post Share on other sites
bmsgaffer 2,053 #4 Posted November 25, 2014 You are correct about the amperage.. It has a smaller 15amp on the inside fuse panel and a much larger 40amp under the hood of the Jeep. But the strange thing about it was, neither fuse was blown...... Rob Sounds like its made itself a nice 35 amp heater from the fried components. (The 40A is probably what goes to the resistor fan control). Glad to hear it stopped burning! I had a similar experience: My first car I had a pretty nice sound system hooked up but I couldn't afford a nice sub woofer amplifier so I bought a Bazooka brand or something like that 700watt mono amp (fuses rated about 80amps). I am a amateur radio operator and my antenna wire ran through the trunk next to where the amp was mounted. Apparently Bazooka does not shield their amps from ANY RF noise because the MOMENT I transmitted on high power there was a LOUD THUMP. Moments later my car began to fill with smoke. I have to pull over on the side of the interstate and I dive in my trunk (i had a Bonneville and the amps were mounted against the back seat, I could have slept in that trunk) and start tearing out this amplifier that now has flames licking out of it. Luckily I always have my tools with me so I was able to toss it on the embankment before my whole car burned to the ground. The amp totally roasted itself in the grass. 2 Share this post Link to post Share on other sites
RMCIII 838 #5 Posted November 25, 2014 Brandon - yours is much more comical than mine! Rob 1 Share this post Link to post Share on other sites
squonk 43,735 #6 Posted November 25, 2014 Those old Bonnies trunks were huge. All you needed was a set of ramps and you could haul all your horses to the show Luxo style! 1 Share this post Link to post Share on other sites
bmsgaffer 2,053 #7 Posted November 26, 2014 (edited) Haha just about! Had the power to back it up too! Get this, I had a bright white bonneville with a velvet red interior (stock color!). I was an electrical guy so I even hooked up LED lights under the dash that made the floor glow red. I thought i was hot stuff... It was my first car, despite the fact that it was a little odd color, i kept that car immaculate. And to think my wife still married me after dating me for a few years with that car! The car was only sold because it was totaled by a toyota tacoma rear ending me at 35mph. Edited November 26, 2014 by bmsgaffer Share this post Link to post Share on other sites
Ken B 3,189 #8 Posted November 26, 2014 Pimp Master Brandon.... Share this post Link to post Share on other sites
bmsgaffer 2,053 #9 Posted November 26, 2014 That was me in high school: 6'+, buck-twenty on a full stomach, glasses, in the amateur radio club! I was pimpin' Share this post Link to post Share on other sites
