Same Newb-Different question! Ignition Switch
So, I am not sure if this kind of question is really supposed to go on here, as it is admittedly not "7.3 Diesel Engine-Related," but is a peripheral problem. If it is not considered "on-topic," my apologies, and no offense taken if taken down. Once again, I did some searches, but when there are this many little detail words in the problem, hard to tell which ones will find a proper answer for you. I am humbly submitting this question based upon the seemingly high level of general automotive knowledge on this forum.
So, the vehicle in questions is a 1988 International Harvester S1654 with an IDI 7.3. Retired Uhaul Box Truck. It has had the rear box removed and a car-hauling flatbed built onto it. I got it dirt cheap because it is a beat-up, dirty old oddball (pics will be posted when I reach enough posts to be allowed to post one!), but when I went to look at it it seemed to run so strong that I bought it despite many shortcomings that would cause concern to a sane person. So I drove it home over about 100 miles, and it still ran great. And, believe it or not got about 14 MPG! So, for the past couple of days I have been going through it and trying to mend some things (see my first post on here, dealing with the usual glow plug circuit questions!).
This AM, having "hot-wired" a glow plug circuit before, I thought I would just do that to see if the glow plugs were working, and if it would then fire up without the ceremonial offering of ether/starter fluid to the Diesel gods. I had looked at and watched a couple of videos on these pages, as well as on YouTube, and thought I knew a technique to use. With the 4 posts atop the glow plug relay, which I had tested to see which carried electric under what key position, and having seen one video that said the two different key-activated posts powered the 2 different banks of glow plugs, I simply ran a wire from each of these posts to one of the glow plugs on each bank. I figured if these glow plugs were wired in-line, which was my suspicion, if a wire went to one, it would travel down the line to the other 4 on that side. With temperatures in the 50's, I figured that even if it didn't power all the glow plugs, even one warming up on each bank might inspire a start. So, I wired everything up, made sure neither of my "jumper wires" were contacting anything else, and got in to turn the key.
Turned the key to on: normal racket from buzzers, dash lights on, WTS/GLOW PLUG light on, etc. Went to turn the key to the START position, and it all went DEAD! No more buzzers or noise, no dash lights, and no starter turn. There was no "pop", "click," "snap," "crack," flash of light, etc. Just NOTHING! I got out and checked to see if one of the wires had contacted something and caused a short and it appeared not. After repeatedly turning the key on, I never got any power back to the key/dash again.
So, I spent a couple hours trying different things, trouble-shooting by searching this site as well as several other sites and search engines, etc. I still have no power to the key switch (it would appear), no dash lights, no warning beeps or buzzers, etc, with the key on. I checked and did have juice making it to the glow plug relay (BIG post on the relay), as well as the main cable to the battery was still carrying juice. The headlights come on. The batteries are brand new and have been working well, and I run it often for long periods while working on it to make sure it is staying charged. All gauges have seemed to work, including the voltmeter, and it has always shown proper function. I DID unhook the cables from the battery and clean them, though they were just cleaned and put on about 3 weeks ago when the new batteries were installed. I also unbolted and cleaned and reattached the negative cable to the frame to be safe. But the fact that there is juice to the battery, the glow plug relay and the headlights work makes me think this was never the problem regardless. I am thinking the ignition switch, but read several posts that warned that the ignition switch was often NOT the culprit, even after people THOUGHT that had to be the problem.
So, my questions is two-fold, if not more. Does it sound like an ignition switch issue? If not, please talk me through it, because I love eventually understanding things!
The other question is: Was there something in my attempt to "hot wire" or "jump" the glow plugs responsible for this event? If so, is it likely I damaged something else in doing this? Does this ancient piece of equipment likely have an ECM type of compnent even-in some posts for some vehicles, I have seen people saying this was the cause or possible cause of their problem)? (Those 3 questions are obviously only one "fold," thus, me saying it was a two-fold question)
And, yet another question, I guess-what would YOU do next to rectify or try to check this issue?
My current plan is to go buy another key switch for it (old fashioned switch and key in one-mounted in the dash, not a key switch in column and actual switch down at end of column) and try that next.
Info of note, I am traveling, have more tools at home, and do not wish to buy a new multi-meter here only for this problem. I have a NICE one at home, which is limiting in this instance for sure, but at some point, even if it means MORE manual tests, shouldn't I be able to diagnose this without it?
THANKS for any info and advice, and thanks for being here!
Last edited by jmshawii; 12-15-2017 at 04:43 PM.
Reason: Found errors/further explanation