ataboy9026

I'm going to dig into my issue today and look at wire harness near master cylinder. I'm going to go ahead and install ESS also. The weird thing to me is when this first started acting up on me it was cold and I had defroster on, which cycles the AC every few minutes automatically. I kinda noticed a "rhythm" to my tach/lights every few minutes. As I got further south it warmed up and I shut off defrost and turned on the vent and it drove fine for about 2 hours so that made me assume it was somehow a problem with AC. It blinked out again so I unplugged AC pump and pulled AC relay and the truck drove perfect for 800 miles. Then it happened once again so I then unplugged the AC hi pressure switch and it was perfect for another 900 miles. Then it all started again and blinking out all the time like the videos show. I did take more videos when it first started acting up but it goes over a minute without blinking and is quite boring so I didn't post them. If you look close the check engine light does not blink with every flicker of the tach needle. And the tach also jumps up a little at times before dropping down... and the speedo actually went up and down a couple mph as the tach blinked a few times. When it all first started I had pulled over and was sitting still and my speedo started reading from about 20-55 mph up and down...AS I WAS SITTING STILL... but that only happened once for about 30 seconds. That kinda made me assume my PCM was bad. I hope somehow I find a short somewhere cause the $700 PCM isn't looking too fun to change.

infidel

Maybe in just disconnecting the various components you moved around the wire harnesses enough to temporarily disconnect a shorted wire.
Quite a few people have found wires with the insulation rubbed off right in the middle of the wiring looms.
Price you might pay after 15-20 years of vibration.

ataboy9026

well I unplugged every connection I could see under my hood and trans speed sensor and sprayed electric cleaner in them twice and dried them with compressed air and put die-electric grease on all of them and wire brushed all battery cable ends (they did have some dark grey gunk/corrosion on them) and also undid the wire loom from A/C back to firewall looking at every wire for bare spots and found nothing inside loom that looked odd... But truck is fine now, I don't know what connector fixed it but my issue is gone....