Good to hear you have the good wiring connector.
Grawolf wrote:Bad ground at the trailer or in the truck? Know of anybody that puts out a decent repair manual for this truck?
Check both. "If in doubt ground it out" is a good rule. The hitch is not a good ground. Check the ground wire at each side near the bumper bracket bolts. This usually only affects the trucks tail lamps, but we have seen several with problems. Also check your fuses under the hood. Just for kicks
The best manual available is the factory GM manual published by Helm. Mine is for sale in the classifieds. You can watch ebay too. They are not cheap, but they are a three volume set covering everything.
Your next best bet would be the big Chiltons manual. It includes wiring schematics, but is not crew cab specific and will not take into account the forward harness we have for the utilities and the truck harness on the back half.