Posted by: John A. on April 25, 2002 at 09:31:21:

My '96 Windstar blows the taillight fuse, when towing our boat trailer sometime during our trips. When this occurs we do not know; but on initial check before each trip all lights operate properly. Could someone tell me what Reading resistance wise that I should get between the Ground wire and each of the other 3 leads? The trailer indicates that it is a short between each ; the van shows open. The trailer is new; which is correct? The trailer hitch installers wired the Van. Thanks.

I understand the lightbulbs being the resistance [the short] in the circuit of the trailer. Why don't I see the same short indication from the Van harness? It is almost as if it does not have a ground, but is floating?Thank's for your help.

As you are blowing the fuse periodically and not immediately after connection, there is a short that is happening from movement, a wire may be pinched or caught somewhere only to become a direct short during motion.