Chrysler Repair: Scanning the 94 Chrysler LHS computer, ambient air temperature, chrysler lhs

Question
Hi Roland,

My '94 LHS is approaching 220k miles and still running great but I'm starting to get electrical gremlins. I love this car and I would like to keep it going as long as possible doing my own work. Currently I've been running into issues with my ambient air temperature sensor in which occasionally it will stick at 75 degrees, when it definitely isn't outside. I've checked the sensor itself with a VOM and it appears to act normally in varying temps. (changing resistance) It's really intermittent and if and when I start the car where it sticks at 75 degrees, about 10min into driving it will fix itself and display proper temperature. What could be causing this issue? Does an open circuit default to 75 degrees? I've run the ATC self diagnostic procedure and it didn't develop any codes.

Also, I've been looking into getting a computer scanner for my car so that I can run the body diagnostics straight from the Chrysler factory service manual. Chrysler at this time used the DRB2 scanner. Now without spending an arm and a leg to get a scanner to do all the body diagnostics what are my options? I hate having to get nickel and dimed at the dealership but I would like to do all the tests they do (body specific.) I've also discovered that the '94 model has a unique computer connector. So called the LH SCI OBD1 connector, only used on that model year which becomes an issue when looking for scanners. Do you have any ideas or scanners that have worked for you?

Thanks!

Answer
Hi Drew,
The ambient temp readout will rather read OC if the sensor is disconnected. I would suggest taking a look at the plugs on the top of the body computer located on the right kick panel because if the windshield leaks water that drips down on the plugs you can get some gremlins. See if there is any signs of corrosion or water around the pin sockets. If so, use some electronic spray cleaner on them. You have to remove the end cap on the console and the trim panel and cut the dash liner to get to the computer. Remove the screw via the oblong hole in the right end of the knee bolster. Remove the lower corner push fastener or the console and maneuver it downward to access the 3 plugs.
On the scanner, I think you would need a DRB II equipped with both the underhood plug-in which it would normally have even though you might not need it, and the data link connector plug for the underdash socket. I believe that anything other than the DRB II will be limited to a very small subset of the possibilities. I bought one on eBay several years ago, but so far have not had any major issues with my simpler '89 LeBaron which doesn't have a body computer. Be sure you get one that has a cartridge for the '94 model year.
Roland