Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
I did some rewiring on my truck when I had to replace the wiring loom for the ECU. I must have done something wrong because I'm getting fire in the start mode, but nothing in the run mode. The wiring diagrams I have don't help very much because some of the wiring under the hood does not match up with the diagrams. When I test for voltage from the ballast to the battery, my Volts/Ohm meter says it's getting -12.5 volts. So I believe something is hooked up backwards. I would like to go through the wiring on my truck and rewire the whole thing. I was wondering, if I were to purchase ScannerDanners book, would it help me with the wiring issue?
Hi sir yes there are many options on after market wiring harnesses and wiring and yes sir scanner danners awesome book will definitely help you in your wiring issues and the diagnostic skill needed to troubleshoot almost any issue
The book will help, definitely, but your wiring diagrams are really going to be your road map. SD testing methods may help you fill in some of the blanks when the wiring diagram falls short.
Since it seems like you're not getting power to the right places when you turn the ignition key, I'd say start at the ignition switch. I grabbed the ignition switch diagram from charm.li for an '85 D150:
Tyler wrote: The book will help, definitely, but your wiring diagrams are really going to be your road map. SD testing methods may help you fill in some of the blanks when the wiring diagram falls short.
Since it seems like you're not getting power to the right places when you turn the ignition key, I'd say start at the ignition switch. I grabbed the ignition switch diagram from charm.li for an '85 D150:
Thanks for your reply. I have the diagram that you posted already. However, I'm pretty sure it's not the ignition switch as it is brand new. In fact, the whole ignition system is brand new. I replaced everything that has to do with start and run. I also replaced the ECU wiring loom which I got from Summit Racing. It also has a brand-new distributor and pickup coil. In fact, I'm pretty sure, that when I did some rewiring, I hooked up something wrong because I shouldn't be getting -12.5 V between the run side of the ballast resistor and the positive battery post. I'm about ready to pull off the whole electronic system and convert it to a points system just so I can get the truck on the road and be done with it. I've been working on this truck for about 3 years now. I need it running because my 2003 Ford Expedition needs a new intake manifold. I need to get that manifold replaced before it does irreparable damage to the engine, if it hasn't already.
Hello Y'all, I just thought I'd give an update about my truck. Just today, it finally fired and ran for a few seconds. It may have run longer if it didn't have massive vacuum leaks because nothing's plugged in. The problem boiled down to a bad red wire that runs from the alternator to the 5-way splice, from the 5-way splice into the bulkhead, and then from the bulkhead into the half-moon connector on the ignition switch. So I did all this other stuff to it, including taking the heads off and lapping the valves, which needed doing anyway and that wasn't the problem. Anyway, while I was at it I also replaced the timing set.
Now to put it all back together and install the brand new custom aluminum radiator with electric fan. Then it'll be good to go.
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