In Reply to: Durango's first glitch... blinker wiring short... DOH!!! HELP ME posted by dieck (dieck) on February 28, 1999 at 11:50:21
You may be able to find it the first way, but the second way is guaranteed to work if it is a bulb problem. (which most likely it is...)
Method 1: Turn on the parking lights. look at front and back of truck, and see if one of the bulbs seems brighter or dimmer than the rest. If one (and only one) is different, this is probably your bad bulb. Remove the bulb, and turn off the lights, and activate the turn signal. If you inside lights do NOT flash, you have removed the bad bulb. If you cannot see any difference, or if more than one is bright or dim, the you will have to resort to method two, below.
Method 2: You will have to remove each bulb that is supposed to flash, but do this one bulb at a time. Start at the rear, since those bulbs are a little easier to replace. Remove the bulb, and turn on the turn signal. if the inside lights no longer flash, you have found the defective bulb. If they still do, stick that bulb back in, and go on to the next. once you have found the bulb which when removed fixes the dashlight problem, this is your bad bulb. The bulb will still appear to light, but it must be replaced.
The reason the inside lights flash is because there are two filaments inside the turn signal bulbs. one lights when the turn signal is flashing, and the other comes on (but dimmer) when the parking or headlights are on. The problem you most likely have is that the bulb has a short inside it, so that the bulb still appears to work when the turn signal is on, but is actually lighting BOTH circuits, turning on the parking lights when the turn signal flashes.
I once had two bulbs on the same side go bad this was at one time. Talk about a nightmare to find... I had been rear-ended, and this apparently caused the bulbs to go bad.