QuestionHello, I have a 1999 Chrysler LHS that blows fuse #17 every time I put the car into reverse. When this fuse blows, the abs and brake dashboard lights stay on as well as the defrost running at high with hot air. The climate control panel goes off and will not work.I have tried disconnecting all of the reverse lights and checking the rear wiring for shorts{none-found} but still keep getting the blown fuse #17. Thank You for any help.
AnswerHi Chuck,
The reverse position of the transmission connects fuse 17 to the reverse warning lights at the rear and to the automatic day/night mirror in the cabin. Either of those circuits could be shorted to ground. When that happens of course all the other devices powered by fuse 17 also fail.
The easiest and most likely point to check for a short to ground would be at each of the reverse warning light bulb sockets at the rear. Use an ohmmeter on continuity test to see whether there is dead short to ground between the center electrode in each bulb socket and ground after removing both bulbs. If so, then check for a possible short in each the sockets proper. The bulb will each have a measureable resistance so you could put one bulb in a socket and notice whether the other bulb socket shows that same resistance to ground or is still dead shorted. If it shows the bulb resistance than presumably the short is in the socket that you are testing at. So reverse the bulb insert location and check the reverse socket.
If there is a dead short to ground as showing at the bulb sockets:
You can check out the mirror circuit by going to the natural color plug at the front side of the fuse block that has 8 pins, and on pin 5 there is a violet/black wire that activates the mirror. Pull the plug out of the socket and see what the resistance is of that pin 5 to ground. It should read at least several ohms.
If that checks out, then remove the reverse bulbs at the rear. Then you need to go under the dash to a plug on the back side of the fuse block which is brown in color and has 12 pins (it is located in the middle of that array of plugs). Pull that plug and measure the resistance of pin 12 to ground, and it too should read infinite ohms, not a short. If it is shorted then you will need to trace the wire from the fuse box back to the reverse lamp sockets to find the short. The wire is violet/black and goes to a splice at the left rear corner (of the trunk most likely) where there is splice to provide a separate wire to each reverse light socket.
There is one last possible short, the violet/black wire from the transmission range switch plug at the transmission to the fuse block. That wire connects to a gray plug on the back side of the fuse block that has 13 pins. On pin 6 you will find the violet/black wire and so you would pull that plug and with the transmission in any gear other than reverse measure the resistance of that wire to ground, which should be infinite.
Let me know how this works out. Thanks for the rating and nomination.
Roland
