92 ignition switch question
 

Ok so sorting thru yet another electric problem. First rotten, destroyed brown wire to the starter. Then a screwy post on solenoid, so off to get a new starter. But, as I was cxing the switch just to make sure I cover all my bases and I find the yellow wire at the key switch is getting .03 volts at rest. Then when I turn the key it goes to zero. The start is off the truck now.

so with a voltmeter i cx for continuity between yellow wire (goes to starter relay) and red and black wire (powering ign switch) and get nothing.

so thinking switch is toasted as well. Does that sound right?

also when I detach or reattach the neg Batt cable I get sparks.... So is there a short somewhere...maybe intheswitch????

Here are the wiring diagrams. The starter circuit in in the first few pages.
http://dens-site.net/Dodge_CTD/1991.5-Wiring_Diagrams/

Thanks

The yellow wire goes through the coil of the starter relay to ground. So no/low voltage with the key in any position other than start is normal. With the key in the start position, you should see 12V on the yellow wire. Is there 12V on the red wire? It is the supply. If not, your supply feed is the problem. If you do have 12V, then the switch is most likely the problem.

O.k. Thanks but can you clarify?
on a smart phone diagrams a bit small. wire that is energizing the switch is the center wire, which is red w/ a black stripe. Theres another red wire that is closest
to the driver that is not energized w/ switch in any position
.

but none the less with key turned to start, wire gets no juice. So guess it off for a new switch, or just install a push button.

thanks

Well it isn't the switch. I changed it and no voltage on the yellow wire when key is turned. The red wire (which looks more pink) is not getting power so I cx'd the fuse box(I put in place of fuseable links) and that fuse was blown (had put in a 30amp) so put in a 40amp and the wipers happened to be on and they came on but blew the fuse right away). So do I have the wrong fuse in there, or is something dramatically wrong?

any insight would be appreciated

There is a red wire and a pink wire going to the switch. The red wire supplies 12V to the switch for the starter and other stuff. Here is were it get to be no fun. You will have to start separating circuits until you find the 1 that is shorted. Then fix it. Printing out the diagrams will make it a whole lot easier to follow.

Both fusible links going to the ignition switch are rated 40 amps. They are used because they blow slower than a fuse.

Well I think I made some headway. I seem to have some trouble with the blu wire(s) under the hood. I replaced fuse links w/fuses awhile back when I was having a/c and other electric problems. So I had cut all the blue wire and put them on plugs (tapin type). So I was able to unplug everything and plug in 1 @ a time

the 2 heavier blue wires(which have continuity between themselves and a plug I mention below) that run across the back of the
engine bay pop the fuse everytime I crank it over. I followed them back to the 2 plugs just above the lift pump. One is gray and 1 is black. It looks like some1d been in their b4. 4 blue wires all twisted together after the plug
1. feeds the pre fuel filter heater, 1 goes to fuel shut off on injector pump, 1 goes???where?for what?,a/c?, last is the tail off the plug.

it was just taped up and coming apart so hopefully that is, it was shorting out
should they all be bundled like that???? cxing diagrams but haven't found it yet

boy what an adventure

Welcome to the wonderful world of electrical wiring. Considering your wiring harness has been hacked up, I'd suggest replacing it. Other option is to take the time necessary to completely repair yours. That is were I was at with my 92, harness overhaul.

Well, in their infinite wisdom, the creators of this electrical system ran a circuit through a 40 amp fusible link, then the ignition switch, then all over the truck to ignite most everything that's critical, like FSS, OD solenoid, grid heaters, etc. Yep, that's the blue wire.

A short anywhere in it will blow the fusible link. When I got my truck it has a bunch of paperwork with it. One bill for several hundred bucks including towing was for a no start issue. Fix was tape up the blue wire to the KSB that got tangled up with the throttle linkage.

Well I think that might of cured it. Untapped all around those 2 plugs and found another splice that was looking ratty. Soldered that up, respliced the blue wires (still don't get why there is 2 feeds going to the same splice coming from the same place....whatever, as long as it works.

found a small black and brown wire going down towards tranny, cx'd diegrams and looked like it might of broke loose from pre-heater for fuel filter so that is where i spliced it. Think its ground for distance sensor thing on trans, odometer stopped working ages ago, so we'll see.

ran a new 10 GA wire from fuse box I installed straight to ignition switch. Bypassed the firewall plug. Now thinking about putting in the relays suggested in sticky. But for now....

cranked her up everything electrical is powering on strong (cab, lites, blower, voltage good, etc.) test run tomorrow.

if all goes well then I might get greedy and try and figure out why a/c stopped working (clutch won't engage unless hot wired. Hopefully, its just low on Freon. Still have the r12 I think.

sure is nice to come in to this sight and get help instead of just banging your head on a wall.. That blue wire was driving me nuts..

thanks a heap ya'll

P.S. So the new ignition wire should be on a 30 or 40 amp fuse????

Fusible link you replaced is rated at 40. 40 amp fuse should be about right.

OK. thanks again. Guess I might as well run a new wire for the other ignition switch feed while I I'm into it...bboy have alot more confidence w/ the wiring now I've actually seen and cx'd most of it.