More Electrical Questions...

[RainMoore]

Hey all,

I've posted on this pretty recently, but I figure a new one just to keep things simple...

I've got a '74 2002 Automatic that I have yet to get started. Backtracking through what I think is multiple POs seriously bizarre wiring over the years. I've begun replacing several wires that were either mouse chewed, frayed, etc. So here's where I'm at, other than totally lost:

 

I've isolated the problem to (I think) somewhere between the coil and the plugs, to which I'm getting no spark.

Pic 1 - I replaced the wires leading to the + and - coil terminals, but have not changed how they were wired before i started. So...The red (+ on coil) spliced into a grey/green wire which goes into the fuse box where I lose track of it (not in any schematic I can find), and the black/red goes down across the brake booster in a taupe tube with four other wires, three of which are just cut, and the fourth (brown/black) goes into a lead on top of the engine. The black/red is also cut and was hanging loose. From schematics its supposed to connect the starter to the coil, so I've added a wire and reconnected it (pics 2 & 3). The orientation of said wire doesn't make much sense to me. It was awkward to get it back around to the starter, tho that could just be old wires.

The black wire goes into the "Drehzalschalter" (google translated to "speed switch") and is connected to the - terminal on the coil. Also not on any schematic I can find.

 

Pic 4 - black and red as described, Blue is to the points.

 

 

From schematics there should be a green wire leading from the ignition to a relay/box then strait to the + coil terminal. It's nowhere to be found. At least, I can't trace it from under the dash into the engine bay, and it's definitely not going anywhere near the coil.

 

I'm pretty new to this but it all seems pretty wonky to me. It looks like someone, at some point, rewired this thing semi-professionally but didn't adhere to the color code of the schematics. And then someone else did a worse job.

 

The starter is firing, it's cranking, and with the multimeter I'm getting 10.5ish V to the coil. The points look alright (a little pitted but Ive filed them flat) and the condenser is functioning, as is the distributor. It's got a blue bosch (so no resistor). Fuses are solid. Everything else electronic seems to be working except the cigarette lighter.

At this point I don't even understand how any power was getting to the coil at all, unless someone wired it through the fuse box first...?

 

Any help would be appreciated on next steps...

Thanks!

 

PS - been looking at the stereo wiring as well. It looks as though someone set it up to be easily upgraded to a several channel system, but there are only two speakers and about 20 wires. It's a mess to say the least. All wired into connector boxes with the other buttons in the console. I only need the four wires (2 for each speaker) out of the back of the stereo right?

Also, anyone know of any reason the hazard light button would possibly be wired into the stereo?...Because it is...

 

 

 

[7502]

26 minutes ago, RainMoore said:

Also, anyone know of any reason the hazard light button would possibly be wired into the stereo?..

Could be the receiver's station preset and configuration settings, is it yellow?

[2002iii]

Ok so from your description and pictures it sounds like your close. You weren't kidding about mouse chewed wires, it looks like the liked the taupe/tan wiring sheath that denotes smog wiring.

 

If the previous electrical butchers rewired the coil correctly the grey/green wire should be the original green wire coming from fuse #12. and they replaced the original resistor wire that was spliced in. So your red wire to the positive post on the coil should be good but it should be getting 12v or more especially with the extra voltage from the starter jump wire. I would check the crimp connectors, fuse connections and all grounds.

 

I'm assuming the wire from the hazard switch to the radio was to power the radio because it was the closest easily available source of 12v.

 

As to the pile of wild snakes radio wiring, I would take the radio and wiring out. Then figure out any wires you don't want or need and shorten them and cap them off and zip tie them together. Then reinstall with a proper connections and cleaned up wiring. 

 

The disconnected wire in the taupe/tan and all the stuff on the firewall in your last picture is smog stuff you don't want or need unless you are in California and it's a 1976 and you have to pass Smog.

[RainMoore]

7 hours ago, 2002iii said:

Ok so from your description and pictures it sounds like your close. You weren't kidding about mouse chewed wires, it looks like the liked the taupe/tan wiring sheath that denotes smog wiring.

 

If the previous electrical butchers rewired the coil correctly the grey/green wire should be the original green wire coming from fuse #12. and they replaced the original resistor wire that was spliced in. So your red wire to the positive post on the coil should be good but it should be getting 12v or more especially with the extra voltage from the starter jump wire. I would check the crimp connectors, fuse connections and all grounds.

 

I'm assuming the wire from the hazard switch to the radio was to power the radio because it was the closest easily available source of 12v.

 

As to the pile of wild snakes radio wiring, I would take the radio and wiring out. Then figure out any wires you don't want or need and shorten them and cap them off and zip tie them together. Then reinstall with a proper connections and cleaned up wiring. 

 

The disconnected wire in the taupe/tan and all the stuff on the firewall in your last picture is smog stuff you don't want or need unless you are in California and it's a 1976 and you have to pass Smog.

Once again, thank you so much for the clear, concise answer. Especially to the smog stuff.

 

Two last questions tho, I thought the green ignition wire is supposed to be connected before the fuse box, so the car won’t die if a fuse blows. That’s what I’ve read on here anyway...

Also, is it a problem that the resistor wire is gone? A little confused about that whole deal, and which coils for which is was required.

besides that everything you said makes this all suddenly make a lot more sense. Looking at different schematics I think someone rewired this according to a standard 2002/tii so the OG automatic wiring is sort of mixed in...

 

last night I removed and cleaned the fuse box, which was super crusty and oxidized, and today I’ll go through and check all the grounds carefully. Probably good to clean the connections, no?

 

And thanks for confirming what I suspected (and wanted to do) about the stereo. I’m pretty sure the power is wired through a large black cable from the unit, and the hazard thing is plugged in through a speaker channel or something. Something new to learn about tomorrow ?

[FunkyLaneO]

The ignition wire does go to the fuse box but it is not fused, it is plugged in on the feed side of the fuses.

 

You have a blue coil so you no longer need the resistor wire, a regular wire is all that is needed, blue coils have an internal resistor and adding a resistor wire would introduce too much resistance and create a weaker spark.

[Son of Marty]

I would recommend you replace those red butt splices with the heat shrink covered ones. The red ones are subject to wire stress/vibration and corrosion causing intermittent wiring problems usually in the dark and rain? , the heat shrink ones seal the splice from the air and provides support to the wires them self.  

[John76]

Your picture #2 shows a black wire (with blue connector) attached to the top tab (#15) of the starter solenoid .

Be sure the other end of this wire is connected to the + terminal (#15) on the coil. Your picture shows only the red wire connected to the + coil. This black (should be black/red) wire provides a full 12v to the coil only when the starter is cranking, bypassing the resistor wire.

2 hours ago, FunkyLaneO said:

You have a blue coil so you no longer need the resistor wire

You should get 12v to the + coil, so check the resistance in that red wire. See my sketch for the location of the "stock" resistor wire section of the green wire coming from the "hot" (unfused) side of the #12 fuse block.

14 hours ago, RainMoore said:

any reason the hazard light button would possibly be wired into the stereo

The hazard button terminal R has a White/violet wire coming from fuse #6, with a convenient connector for the radio power.

 

11 hours ago, 2002iii said:

all the stuff on the firewall in your last picture is smog stuff

Yes, since you have a '74, you (technically) don't need the smog stuff. Make sure you cap all the vacuum sources on the manifold.

(see my sketch for what can be deleted)

[visionaut]

2 hours ago, John76 said:

see my sketch

John — your illustrated wiring sketches are simply THE best!!

 

I actually enjoy reading them. The style is charming and it’s so easy to relate to what your see (or should see) in front of you.  And they’re isolations in on just the bits you need know for a particular electrical component or situation.

 

They’re so much better than the boring and difficult “everything together” overly dense official diagrams. You should maybe get a publisher my friend... there’s gold in them there doodles. ?
 

Kudos bro,

Tom

 

Collect ‘em all!

Edited April 9, 2021 by visionaut
spel

[John76]

12 minutes ago, visionaut said:

They’re so much better than the boring and difficult “everything together” over dense official diagrams.

Thank you Tom!

There is a back-story to my madness. 

When I put my car up on blocks (23 years ago) to refresh the head, I experienced major project creep. I had almost the entire car in pieces, with parts in boxes stuffed into all corners of my basement. I labeled all the wires, parts and connections with masking tape!

Work, family and life in general consumed the next 19 years. My wife used the empty shell of my car in the garage as her storage bin for our Goodwill donations.

So, when I retired, and had the time to reassemble my car, I discovered (to my horror) that all my masking tape labels had dried-up and fallen off. Thanks to our great FAQ forum, I was able to find a '76 wiring diagram.....but, as you mentioned, found it really hard to use. I even enlarged it to 2' x 4' poster, and color-coded at least the power and grounds.

Now I have individual sketches of all the circuits that I had to check, clean and reconnect. 

If anyone wants/needs a diagram, just send me a message. I'm always glad to help !

John

 

[Georges]

You might consider just rewiring the whole car. Insulation has a limited lifespan and fire is no joke. Our cars are not that complicated. My skills are limited but I've rewired a few 1960's cars. It's actually kind of fun and makes it really easy to solve electrical problems in the future since you've touched each wire. Just be faithful to the color codes so the next guy will be able to figure things out.

[RainMoore]

8 hours ago, John76 said:

Yes, since you have a '74, you (technically) don't need the smog stuff. Make sure you cap all the vacuum sources on the manifold.

(see my sketch for what can be deleted)

 

Thanks so much for all the info and the diagrams! I've finally figured out what's going on and I'm goin to fully replace the green from the fuse box and the black w/red from the starter. All this crimping can't be good for longevity.

Getting a full 12V exactly across the Coil as well as the coil to the points, so that's an improvement. The car even sounds like it wants to start more than before when the starter cranks.

 

Still haven't gotten a spark but I'm thinking it has to be the points/condenser at this point...I set the points today but to no avail. Don't have a timing light or device to set the dwell.

 

As for the smog stuff: I'd love to get rid of anything extraneous, but I'm a little lost on the diagram exactly what exactly is part of the smog system. I think quite a bit of it is already gone, as the little round device with the red white and blue markers is totally disconnected, and a few other wires coming off the relay next to it have already been cut.

The one part I'm pretty sure is still there is the brown w/black wire to the coolant temp switch. Is that poking out of the intake manifold?

Also, there's only once vacuum tube coming off the weber carb to the distributor. I don't see a manifold vacuum or I don't know what it looks like...a common problem for me at this point.

 

Thanks again for the diagrams!

['76mintgrün'02]

2 minutes ago, RainMoore said:

Don't have a timing light or device to set the dwell.

This will do both!  Plus it has a tachometer and volt meter built in.  

 

https://www.summitracing.com/parts/ino-5568

[RainMoore]

20 hours ago, 2002iii said:

I'm assuming the wire from the hazard switch to the radio was to power the radio because it was the closest easily available source of 12v.

 

I think you're right! Tho there's also a large black cable off the other side of the stereo which goes into the frame so maybe the hazard wiring is some kind of on-switch when the ignition is triggered?

 

Putting the damn console back together properly was honestly the most difficult part so far haha. That thing is a pain. Not what I was expecting. Discovered more 'butchery' down there, unsurprisingly. Lots of cursing and some zip-ties later and its holding together well.

Some of the plastic for the speed nut 'clips' have snapped off the main part of the console so I'm trying to figure out a way to hold the footwell side panels on...

 

Finally got the main wiring for the ignition figured out, and will totally replace the needed wires tomorrow. Thanks for your help on that, I was thinking about it backwards. All makes sense now.

 

I forgot to mention that apparently when it was last being driven, the car had started dying at stop signs/lights after being driven for a little while first. This could totally be an electrical issue, I'm sure, but I've discovered that the kick down cable is completely severed. Could it be holding a high gear even when stopped? How important is that? Seems not many on here have automatics...

 

Thanks again!

[RainMoore]

4 hours ago, Georges said:

You might consider just rewiring the whole car. Insulation has a limited lifespan and fire is no joke. Our cars are not that complicated. My skills are limited but I've rewired a few 1960's cars. It's actually kind of fun and makes it really easy to solve electrical problems in the future since you've touched each wire. Just be faithful to the color codes so the next guy will be able to figure things out.

 

I'd like to eventually. I'll never get near solving the rust issues I have until I strip it completely. For now I've got super limited space and not much budget, so I just want to get it running well and looking solid and learn what I can along the way!

And yes, I will be sticking as close as possible to color codes, I've already been struggling with identifying what's what. Someone had used what looks like industrial lighting wire for part of the ignition. Super confusing.

Thanks!

[Son of Marty]

The kick down cable will shift it to a lower gear when you floor it, the tranny will select the right gear with out the cable but it will be slower accelerating and in some cases the engine might lug. If the large black wire is a coax cable it's your antenna.

Edited April 10, 2021 by Son of Marty