So it appears that 86 Has power with ignition on or off and 85 is grounded when ignition is off and has 12v when ignition is on.

Therefore terminal 85 is the pin that gets 12v from the ign sw and my problem is that 86 should be grounded full time rather than getting power.

If thats the case I need to figure out why during a partial throttle pull pin 86 suddenly switched to positive rather than grounded

Thanks a ton for the help RB!

 

:thumbsup:

 

Anyone have a source for a wiring diagram? I've been looking for a field service manual but all I can find is scams and owner manuals.

I've gotten down to finding the 2 orange wires leading to pin 86 but after about 8inches they disappear completely in the main loom and Id rather not cut into the loom.

 

Closest thing you can get to a wiring diagram is the FSM.

You can get it on ebay on DVD or USB; maybe $15 or so. Best $15 you'll ever spend on your truck.

https://www.ebay.com/sch/i.html?_fro...do&_sacat=6029

 

Thanks I went ahead and forked out the cash for one.

Well today I went out to see what was going on and noticed the IGN relay was no longer going haywire but the fuel pump wasn't kicking on. About that time a buddy showed up and was messing with the connectors going into the bucket and I happened to bump the ignition on to check something else. Voila it kicked on! Upon further investigation the connector from the racetronix hotwire kit to the pump has a pin or 2 that aren't making good contact. I bypassed the hotwire kit and the truck works as it should.

So technically the IGN relay problem was never fixed it just temporarily went away. Intermittent electrical issues are the best.

 

Nobody likes to admit their own failures but since this may help someone else I'll update the official cause.

Just Saturday I put over 100miles on the truck blasting around town running errands without any issues. Wake up Sunday and the fuel pump wouldn't come on again. I pulled the relay, tightened the battery cables and boom back to life it came. Then about an hour later at 5,000rpm it died and I had to get towed home luckily only 2 miles from the house. The other symptoms were the ignition relay clicked randomly, 1 headlight wouldn't come one and a single high beam would come on at half power and sorta flicker. As well as the 2 step activation light would flicker. So I was convinced it was ignition related.

Spent all day Monday replacing the ignition switch which I was certain was the culprit and no luck. Tonight a buddy and I pulled the entire fuse block out chased every wire we could find only to go to dinner and accept defeat. After dinner we decided to go over the grounds again. 1 on driver side of block, 1 on front of accessories brackets, and 2 on back of block/head. After laying on the blower with my hands between the motor and firewall I felt every wire carefully to assure it was attached to something and found that everything seemed good. Just for and giggles I clicked the key over and boom the fuel pump came to life, the headlights came on and my 2 step light lit up. I realized it must have been something I touched. Well turns out there are 3 grounds on the back of the motor and one somehow got wedged under the blower manifold and was hardly reachable. Jumped up gave it a wiggle and sure enough the pump went off again.

Well I ended up extended the wire and mounting it to a good secure bolt which 100% Solved the problem.

What's frustrating is everything I googled said "check the grounds at the back of the motor" I completely dismissed them thinking that I had already verified they were good.

Oh well lesson learned and maybe this will tell the next guy to STFU and go recheck the grounds.

 

Glad you found it.

I guess that accounts for why the relay pin that was supposed to be staying grounded, wasn't.

 

Yep thanks for the help. It was difficult because everytime I'd check contacts the values would change. Starts to make you go a little crazy. I think when the motor comes out next (hopefully not soon) I will extended all 3 grounds and find an easy spot to put them. Somewhere that can be visually verified with the blower/Intake on. Same goes for my Tahoe.

 

Thanks for updating, i hate when i search old threads and they never come back with what was the problem..