Alt. signal wire

[Raider L]

Here's what I did today. I followed the excess wiring I don't need anymore. The less wiring to have something go wrong the better.
Below is what that splice looks like that comes from the alternator, and in ya'll's case goes into the engine compartment harness. There are three wires: center of the photo, #12 red, #12 white, and a #16 brown. The red wire is spliced in two. One goes in the cab for 12volt power. And may go to the battery cable at the starter. The white wire is connected to another #12 red and goes to the junction block on the firewall. The #16 brn-25 goes to the firewall wire block and goes inside where it comes out of the interior wire block as a #24 brn-130 which is the exciter wire that goes to the #12 orange wire at the ignition switch, black plug. That's the one that caught fire in my truck. And another wire in the same hole as a #16 brn-25 that goes to the alternator light on the instrument panel as a red light. This light provides resistance so the alternator will start making voltage. When you start your truck that light comes on to tell you the field windings are being energized. After a moment or two that light goes out. If it doesn't the alternator has a problem, usually the voltage regulator.

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The photo below are three wires in the center of the photo that are stretched out. I no long needed them and didn't from the time I rebuilt my truck. I just never removed them from the harness, to lazy I guess until I had a real problem. Now it's time to take them out and any other wire I don't need. The #16 green wire is what's left from the old idle stop solenoid that went to the two bbl. that used to be on the stock engine. The #20 tan wire went to the old A/C temp. switch. I bought this truck in '81 and it had A/C until six months later when the compressor froze up. I took it out and this is a left over wire. The #20 black wire with the white stripe is what's left from the old stock amp meter gauge I had in the instrument panel. It didn't work so when I put in the Autometer amp gauge I had to rewire it the way Autometer said using #10 wires. Besides my old amp gauge didn't work anyway and I couldn't use the original wiring for the Autometer gauge and I left the old wire, until today. I cut it out along with those other wires to finally get rid of it altogether.

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If you have factory amp gauge you ought to have wires down on your starter where you'll see two of those plastic fusible links. There should be a #16 black wire that goes into the link and comes out as a #20 orange wire that either goes to a small screw between the big starter ground wire and where your battery wire bolts to. In the photo below is what the other end looks like that goes to the wire block in the firewall. It has a 10 amp fuse in one of these kinds of holders. I cut all that out today from the starter and over to the block on the firewall. Here's what it looks like.

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Below is my new terminal end I put on the #12 red power wire on the alternator. And, @SirRobyn0 I'm taking your advice and putting in that new alternator I had put back as a spare instead of just electrically checking out the old alternator, which I did the other night that was in there when the fire occurred. It's a newer kind of alternator like mine. It even has needle bearings on the bottom of ther case halves. My old alternator cases have just bushing bearings in it that I had just replaced when I rebuilt it six months ago.

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[Raider L]

@SirRobyn0
Know what this is? I had to look it up. This goes in the alternator (below photo) on top of the voltage regulator. It's a resistor with fine little wires wrapped around the body, to provide resistance to make the alternator energize the field winding's in place of a light on the dash, which I did have in my old instrument panel. I forgot about it when I rebuilt the truck and am just now going to put one in so that fire thing won't happen again. Not having the light may not have been what caused the fire but I can remove this part from the new alternator since I will have a light connected to the alternator.

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Below is my new alternator light. I decided to put it in between the new amp gauge and the volt meter, both of these gauges I have new Autometer gauges to replace these earlier style Autometer gauges. They are both new "Sport Comp" like all my other gauges. I guess I'll be able to see that light come on, and especially if there's a problem. I'm always checking all my gauges anyway when I'm driving. I just sweep across them and only takes a split second after having the truck for forty something years.

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Below, a blurry pic (ha) of the little wiring. I had got a couple of #20 wires at the wrecking yard last week end when me and my son went. and that's what the schematic says it's supposed to be is a #20 gauge wire, and the one I got was brown. I had that in mind when I found this one.

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This photo is how that resister goes in the alternator, attached at the diode trio and the voltage regulator. The screw is insulated to the diode trio and the voltage regulator but goes to ground in the case with the other screw.

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[SirRobyn0]

I have seen those type of resistors before, but would have had no idea what it was for.

Interested in seeing the next update!

 

[Raider L]

@SirRobyn0,
I'll finish putting the conduit back on the engine wiring tomorrow and then I go inside to repair a couple of the wires that got scorched. Also I'll make up a wire I can use to double check that alt. signal wire coming from the alternator into the engine side fire wall wire block continuity. What I'm thinking is to by pass what's left over of the burned alt. signal wire, there's a pic of it in these photo's, and if that is definately the signal wire, but instead drill a small hole next to the engine side firewall wire block, put a tiny grommet in it and stick that 16brn-25 wire that is the signal wire coming from the alternator and on the inside put a terminal end on it with the new signal wire and the 16brn-25 wire that goes to the new light. That way it won't be in the bundle of wires coming inside from the inside firewall wire block. So if anything goes wrong, hope to god not, it'll be by itself and not touching any other wires. Pictures at 11:00. (old TV news saying)
Hey, it's my truck, it's a hot rod, I can run wire any 'ol way I want, huh?

 

[SirRobyn0]

That's right do what makes sense to you, it's your truck! But your plan makes sense to me and I'm full confident that it'll be just fine and not melt down again. Not to take away from your thread at all, but I've just embarked on my own wiring nightmare on my Jeep. The PO installed an aftermarket radio and CD changer under the back seat. The CD changer died a few years ago and the radio quit last week. So with new radio in hand I opened up the dash pulled the old unit out and found this huge mess of wiring. Looks like someone vomited wiring in there. So that will be fun sort that out but probably not as much fun as you are having.

 

[Raider L]

@SirRobyn0 ,
Oh my god, ha, ha, ha! I like that word, "vomit" I can see that in my minds eye. Well, good luck. Find the schematic on you Jeep and I suggest you do what I did and that is take the book, or print the schematic and take it to a print place and have them blow it up big enough so it's real easy to follow every wire from start to finish. That's like I mentioned is that after many years of ignoring the extra wire, especially on the starter I got up the guts to cut all that extra wire off the starter that didn't go anywhere anymore. In this case it was the old stock amp meter wiring on the starter and where it went to on the firewall block. And then cut out more of the old stock wiring on that same block.
I was considerate though and left a little over an inch at the firewall block, just in case...just in case the truck ever ends up in someone else's hands and they want to return it to stock, I can't imagine why, but I have learned since I've been on this site that there are many who like it stock and are prepared to defend the stock configuration. I learned to respect that about you guys, and have to think in your frame of mind when I'm discussing any condition or any change with the truck. You don't want it that way, like I've done to mine. After over twenty-five years with hot rodder's that person's mind gets stuck in that way of thought.

 

[Raider L]

I was thinking last night about the wire catching on fire. I have been really reading that section in the factory maint. book on the alternator and working hard on comprehending what various functions are the alternator has. I've rebuilt that alternator many times ever since I've owned that truck since 1981. But it dawned on me I have never replaced the field windings, the center part you take out when rebuilding the alternator. I've replaced everything else including the case bearings. I did exactly all that this last time a bit over six months ago, that is all except the field windings. Oh sure, I've tested it every time I overhauled it.
Then last night, I guess I have done this before but not after a wire caught fire, just a regular rebuild. I realized that the field windings in that alternator are the original 1974 part put in that truck at the factory? 49 years ago!! I think I've got my money's worth out of it.
I have read in the maint. book that if the field windings go out even though they test okay can have a wire burned in it causing the alternator to go out of whack I would suppose. It says the part would need to be tested on a machine to find out for sure. I was about to put that alternator back on the truck instead of the brand new one I've got. So I took it back out. This time what I had done after testing it, was put a new higher rated voltage regulator in it. I'll take that out and put it in the new alternator. I don't like the lower, 14 or 14.2 voltage regulators. I have for many years used the 14.6 voltage regulators. That way if you've got everything on it doesn't drop below 14.2 or the least 14 volts. The 14 can still drop below to 13.8 or .6 if you've got everything on. That's way to close to the 13.6 lower threshold. Then you have to go to the back of the alternator and touch that voltage regulator tab inside that opening back there while the engine is running. I've done that on Dodge alternators before but not this Delcotron 10SI. And don't want to. I'll get another voltage regulator before I go and stick screw drivers in the back of a spinning alternator!

 

[Raider L]

Well, I was in the engine compartment finishing getting the conduit back on the alt. wiring and got to looking at the new amp gauge wire at the junction block. I had followed the schematic and installed a #16 black wire from the #12 red alternator wire to the junction block as the "fusible link". You can see at the top right of the photo how I curved the #10 black wire which goes to the red alt. wire side for the new amp gauge.
The Autometer instructions says to "splice" the #10 black wire to the #12 red alt. wire. So near where those wires cross is where the splice is going to be.

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As in the photo below.
I'll cut into the red wires insulation a bit about 3/4" back from the cut end and trim off the amp gauge black wire's insulation and solder them together at that point. Then put a large piece of shrink wrap on that union. Then where the end of the red wire is I'll reattach that #16 wire in the photo above and that wire will be soldered to a short piece of #12 red wire to go back to the junction block so it will make a real fusible link. Like, isn't that what the fusible link is supposed to be, the place that will melt before something else burns up? You'll see how I do it tomorrow. I hope to do a good job so it will look nice instead looking like a bird took a dump on two wires.

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[Raider L]

If you go back to some of my previous posts on the wiring I've done you can see how it was wired before this time. I had a #12 wire going over to the junction block from the alternator. But since this time with the fire and all I had to get the schematic out and make some corrections. As long as your wiring is stock you don't have to worry about anything. It's just my wiring is modified since I put in a MSD 6A box, a MSD remote timing control which rewires all the coil wiring to a control box, and that changes up where all the coil wiring goes. So unless you've got that sort of setup then you don't have to worry about your wiring. A couple of weeks ago @T tadKingnkc had a question about wiring and I made a comment about how I did mine, but mine is unique in it's application, not stock. Oh yeah, he was remaking about all the wiring that went over the valve cover and then back under the head back down to the starter. I told him I noticed that when I was rebuilding my truck and decided to cut all that wire out and go from the firewall harness straight down to the starter since that's where it goes anyway. I cut out 5 ft. of excess wiring.
It may not be interesting to some who are inclined to mess with the stock configuration of their truck, but I fancy myself a hot rodder and can't leave anything stock. When I cut all that starter wiring out I ended up putting the harness half on a fenolic block I mounted on the firewall, then the other half on screws in a lower setup on that same block. That way I could also use a remote starter there if I needed to and hook it up there instead of going all the way down on the starter. there are some good photo's of it if you look for it. I think in the posts about wiring up my new amp. gauge have got the pics of that fenolic block.

 

[SirRobyn0]

I'll be interested to see the completion. I haven't really changed my stock wiring, but I have added many, many feet of wiring for all my accessories. No doubt you or I can make, or build a circuit better than original. Just take a look at some of the original connectors that were crimped on with little to no moisture barrier. You or I would solder that and shrink wrap it. Good luck tomorrow.

 

[Raider L]

@SirRobyn0,Here is the final wiring. I stated yesterday I had to redo where the new amp gauge wire was located because I added the #16 fusible link wire to the alt. wire so I had to redo the new amp. gauge wire. That's okay.
Below is the splice that Autometer said to do with the alt. wiring. I left a little pig tail to attach the #16 fusible link wire.

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My strink wrap is in place before I soldered the wires and now the #16 fusible link wire is in and shrink wrap ready to heat. The fusible link wire now goes to the correct post at the junction block.

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Done. I did go ahead and attach a piece #12 red wire to the other end of the fusible link wire as I believe that it won't matter because by the time it fries that #12 wire won't be cqarryingf any load anyway. And it's according to the factory schematic in fig. 1 junction block diagram where there is a #10 big wire that the #16 fusible link wire share on that same post. So it's spec.

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Below is the finished job of rewiring the new amp. gauge wire, and the relocated fusible link wire attached at the junction block. On the right side of the pic in the harness you see three conduit's coming together, the top one is the separate amp. gauge wiring, the lower two are the factory wiring harness wires going to the firewall block. I put in some zip ties all along the three to pull everything up tight to the adel clamps so nothing is sagging or flopping. The conduit going past the distributor is the alternator wires going back to the alternator. I put one whole piece of new conduit over those wires because the old one was to dirty looking and broken midway across the intake manifold at a clamp I had there. Now there is a new clamp in that location to hold the alt. wires up off the intake and to keep the conduit from moving.
Where the #10 black wire comes out of the conduit and is spliced to the #12 red alt. wire? If you follow that conduit over to the left you see where the other #10 red wire is attached to the fenolic block. That is the battery cable and the wires going down to the starter. Where the #10 red amp. gauge wire is connected that is one leg of the amp. gauge wire, and up where the #10 black wire is attached to the alt. wire is the other leg of the amp. gauge wiring. See, no ground wire. Both wires go to 12 volt wiring, one the 12 volts to the starter coming from the battery, the other goes to 12 volts coming off the alternator/ignition from a keyed source. The gauge measures the two 12 volt sources to check whether the battery is being charged and there is no discharge.
Your stock truck probably does the same thing but through the amp. gauge at the printed circuit board, that is if you have gauges. And as I have found some trucks with gauges didn't have the amp. gauge. Mine did.

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[Raider L]

@SirRobyn0,
You said you don't build your own alternator? I do. So what I've done is to take a pictorial review for you and anyone else who is afraid to tackel that job. It's real simple. Now I don't explain principal but I show you how to take it apart and put in the voltage regulator and take out the rectifier bridge if you ever need to and what tools to use.
Go to Alternator rebuild. It will be in this catagory, electrical. I'll start a new thread for it. I'll do it tomorrow 'cause it's almost midnight here.

 

[SirRobyn0]

Looks like great wiring work. I'll probably outlast you or I lol. I look forward to reading the Alternator rebuild thread, that'll be some valuable info a lot of folks will probably appreciate.

 

[Raider L]

Today i re-routed the alt. signal wire. Here is where it comes into the cab from the other side. I double tested it for continuity to make certain it was the correct wire.

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Here's the engine side. I had cut it loose already.

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I will solder a new wire the same color to this wire, hanging next to the pencil, and send it inside.

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[Raider L]

Below is the signal wires new hole. I'm not going to put the alt. signal wire in the wire bundle on the inside anymore. I'm running it by itself, just in case. It took me several days to repair all the wires that got burned when the signal wire went up in flames. I had to cut all the damaged areas out of each wire under the dash and solder in new wire. So the heck with that. This way the signal wire will be by itself

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This pic below shows the grommet I inserted. Instead of just guessing what size hole to drill I used my vernier scale and measured the inside of the grommet that will fit up against the sides of the hole. That inner part of the grommet that fits the actual hole measured .360". I looked that up on a card and the nearest size drill I could find was a .359" which was a 23/64" drill. I drilled the hole, below, and the grommet fit perfect, no side slop and not to tight.

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After I soldered the alt. signal wire to a lenght of same size and colored wire then I inserted it through the grommet to the inside. Then puished a little extra signal wire back into the conduit and taped around the conduit to stop it from slipping out any further.

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