mikekaz1 Posted November 23, 2015 Share Posted November 23, 2015 so my reverse lights have always worked percfectly. never an issue, idk if it was caused by it or not but seemed to coincide with it...t, but I happened to install a electric fan to replace the mechanical, and then I also wired a jumper to the factory fan coil. works perfectly. but it seems ever since about that time my reverse lights don't work. I know the reverse goes through the NSS but ive never had an issue with it, but where does the power come from? I couldn't find a specific or labeled shared fuse. Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 23, 2015 Author Share Posted November 23, 2015 I can only start in park and neutral and it starts perfect every time (which is correct). and even when cycling through the gears slowly there's NEVER a point where the lights turn on. dead all the way through. Link to comment Share on other sites More sharing options...
Pete M Posted November 23, 2015 Share Posted November 23, 2015 there is also a connector behind the drives side rear tire that is known for having problems. it was the reason my brake lights didn't work. :( Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 23, 2015 Author Share Posted November 23, 2015 so i was correct its cooling fan related... i don't understand how or why though... and i don't know a real solution... but long story short,if i put 12v to pin 85 of the cooling relay, i get my fan to work, but not the reverse lights and if i put power to pin86 i get my reverse lights to work, but not the fan. and if i put power to both, nothing works. ....but when i do apply power to pin 86 i also get this small plastic box to click also... i was told it was the fuel pump ballast bypass relay, but i don't really understand what it does.... although it clearly controls more then just the fuel pump. Link to comment Share on other sites More sharing options...
Blue88Comanche Posted November 23, 2015 Share Posted November 23, 2015 There is a relay that gives power to the E Fan, it is the same type of relay that is used for the Fuel Pump, AC, so on. to test for function any of those relays can be swapped with another. Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 23, 2015 Author Share Posted November 23, 2015 There is a relay that gives power to the E Fan, it is the same type of relay that is used for the Fuel Pump, AC, so on. to test for function any of those relays can be swapped with another. yep i know that, those are the pins i was applying power too. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 23, 2015 Share Posted November 23, 2015 I explained exactly how to wire the ground signal (not 12V) to the aux fan circuit to turn it on. It appears you did something differently. What it is and how it affected the backup lights I have no idea. Suggest you invest in a factory electrical manual specific to your truck. The ballast resistor relay's job is to switch the full 12V fuel pump supply voltage from the fuel pump relay used for initial starting to the ballast resistor after the engine starts. This lowers the operating voltage of the pump and makes it quieter. Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 23, 2015 Author Share Posted November 23, 2015 I explained exactly how to wire the ground signal (not 12V) to the aux fan circuit to turn it on. It appears you did something differently. What it is and how it affected the backup lights I have no idea. Suggest you invest in a factory electrical manual specific to your truck. The ballast resistor relay's job is to switch the full 12V fuel pump supply voltage from the fuel pump relay used for initial starting to the ballast resistor after the engine starts. This lowers the operating voltage of the pump and makes it quieter. I tried toggling a ground, but it didnt do anything, but power would. thats why i went to power instead to test. i bypassed everthing currently by having the relay removed currently and pin 30 jumped to 36, which makes my reverse lights work, when put into reverse as normal and an aftermarket aux temp switch into 87 for my fan Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 23, 2015 Share Posted November 23, 2015 Was the engine running when you were doing the testing? Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 24, 2015 Author Share Posted November 24, 2015 yes it was runnning, through all testing Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 24, 2015 Author Share Posted November 24, 2015 GOT IT! so... after scouring the inter webs for hours I finally found a matching diagram and traced just about every circuit that goes through the PDC and found my list of wrong/bads.... my ignition switch was slightly loose under the dash. (may or may not have impacted this issue), the ignition fuse 6 in the PDC was blown (my ignorance, i tested across the pins instead of removing) which controls, cooling fan, reverse lights, diag conn, cruise, AC, ballast, (never noticed as i don't have any of those other things or they have redundancies) and the ECU pin 31 fan coil connection was loose and fallen in the socket and not making a connection. fixed all those issues and my reverse lights now work and my factory electric fan works also (although it doesn't turn on till ~250*f). i have power and grounds everywhere i should and the negative trigger/jumper "cheat" for the ECU 31 now works to! going to try an aftermarket stand alone temp gauge to confirm or deny dash gauge. if they are really that high I'm going to run a negative controlling relay from my standalone temp sensor to the ECU 31 to turn it on earlier, but also allow the factory system to function normally. and thanks hornbrod for putting up with me over the last couple days with my onslaught of questions and stubbornness! Link to comment Share on other sites More sharing options...
mikekaz1 Posted November 24, 2015 Author Share Posted November 24, 2015 this has been working effectively since the install. I used this http://www.ebay.com/itm/like/191618608304?lpid=82&chn=ps&ul_noapp=true standalone fan controller. and have had no issues keeping my temp under control Link to comment Share on other sites More sharing options...
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