Strange NEW electrical problem??

[mjr45]

Thanks for all the input, tomorrow I'll clean up the ground to body from the battery - terminal. that'll let me know for sure there is a good ground. Thanks again.

[Pomorza]

mjr45

https://www.dropbox.com/s/5lox5pojhtzinzb/76circuit_COLOR.pdf

That's a link to the full one, it should be a PDF which you can zoom into. If it doesn't work lemme know.

Hope it helps

Jan

[mjr45]

Jan I was able to print up a 4 page copy from your attachment that I enlarged and printed, taped the pages together and viola' a decent color wiring diagram.

[mjr45]

Captain, I didn't take any pics of the harness unwrapped, it actually didn't occur to me until after I had re-wrapped it, sorry. Basically there are multiple harness's in the thing with wires branching out to the AFM, TPS, CSV, AAM, injectors, water temp sensor, water temp sending unit, thermotine, and the gizmo (in the side of the thermostat housing) that senses water temp and makes some type of advancement adjustment which I have completely removed since the wires were toast and its not really necessary with a ZX dizzy.

[TomoHawk]

An idea I was thinking about implementing recently was to laminate the entire sheet, so you could use dry-eraser markers to trace a circuit right on the sheet. You might even use different colors, or use colors on an uncolored printout.

[Captain Obvious]

Captain, I didn't take any pics of the harness unwrapped, it actually didn't occur to me until after I had re-wrapped it

No worries. Thanks anyway. I just couldn't really picture what you were talking about there and I wasn't sure if the stuff you found was:

a) Factory original weirdness

Age and heat related insulation degradation weirdness

c) Modifications from a previous owner

The reason I'm asking is that I've been messing around with the FI harness myself lately (on my 77) and I'm wondering if I should dig in and look for this kind of stuff:

There were also a red and green wire in the harness to the temp sender that had been cut off and just bare ends which I also wrapped with electrical tape to give some insulation.

I have stripped the harness back just a little in some spots and know what you mean with way they "pre-group" some of the wires based on their ultimate destination. But I've not found anything weird like that...

[mjr45]

Captain,

The harness had been untouched as it came from the factory, but due to age and heat you'll find a lot of the wiring has cracked and broken insulation exposing small areas with visible wires. The other thing I've thru out the car is the wiring connectors are corroded and if you replace them, you have to cut back the wire to find fresh copper or you can't solder or put in new connectors. The solder won't stick to the old wires very well, but then when it comes to soldering I do a pretty good job of welding.

[Willoughby Z]

"...wiring connectors are corroded and if you replace them, you have to cut back the wire to find fresh copper or you can't solder or put in new connectors. The solder won't stick to the old wires very well..." -mjr45

Snipping the corroded end of a stranded copper wire maybe be possible when you plenty of length too work with after cutting. Sometimes, often, there's not much to work with or to sacrifice.

Here's an effective and safe method to clean wire. A vinegar/salt solution to etch and a baking soda solution to neutralize the acidic/corrosive effects. Any small glass or plastic container will do. I've used old, clean model paint bottles, test tubes, medicine bottles, etc.

I've had success with soaking connectors- pins/terminals and all- without removing or replacing anything. I always follow up cleaning and/or soldering with Caig G5 spray to slow down corrosion.

[mjr45]

I agree with you Willoughby, and your cleaning solution sounds good, I'll have to try that next time I'm fixing wiring problems. Several times I've had to solder short (2-3") pieces of correct gauge wire to make connections work. Granted the wire color is not the same in some cases, but anyone tearing it apart at a later date should be able to see whats what.

[Wade Nelson]

"... A vinegar/salt solution to etch and a baking soda solution to neutralize

Hmm from what little chemistry I remember I'm not sure I'd want to add salt to the mix. Any idea what benefit adding it has? I'd especially want to dip only the tips of the wires into the witch's brew so NONE Of the salt could wick its way up inside the insulation to start an entire NEW generation of corrosion.

Perhaps substitute tin or zinc or some other "sacrificial" metal for the sodium chloride?

What about using CLR instead of vinegar? I've had absolutely AMAZING results with CLR on rusted lawnmower parts, carbs, gas tanks, ... greatest stuff ever invented! Remember using "Navel Jelly" and a wire brush? My belly button is STILL sore!!

W

[TomoHawk]

The Caig DeOxit 100 is what you want to use on connectors that are corroded. The D5 product is only used for maintaining your cleaned connectors, like on your home A/V equipment.

I have recently soldered wires on my car successfully. All I did after stripping the insulation off was to use fine steel wool to get the corrosion off.

As for soldering the little extensions, how about some color-matching heat-shrink?

I thought "naval jelly" was used on aircraft carriers?

[Willoughby Z]

Hmm from what little chemistry I remember I'm not sure I'd want to add salt to the mix. Any idea what benefit adding it has? I'd especially want to dip only the tips of the wires into the witch's brew so NONE Of the salt could wick its way up inside the insulation to start an entire NEW generation of corrosion.

Perhaps substitute tin or zinc or some other "sacrificial" metal for the sodium chloride?

What about using CLR instead of vinegar? I've had absolutely AMAZING results with CLR on rusted lawnmower parts, carbs, gas tanks, ... greatest stuff ever invented! Remember using "Navel Jelly" and a wire brush? My belly button is STILL sore!!

W

This is two solutions, Wade.

There's no adverse reaction to mixing salt with vinegar. All you get is... well, salty vinegar. Now, vinegar (acid) and sodium bicarbonate ( alkaline) would get a little fizzy, for sure.

The first time I tried this technique was on battery cable ends. It brightened the copper and I'm sure that some etching solution wicked up the strands but so will the neutralizing solution. I've not seen any adverse or accelerated corrosion above the area I soaked- the insulating jacket shows plenty of strands to make that statement.

I've done this since then, primarily for soldering and brazing, to achieve a clean, oil free, non-corroded surface that the strands or sloid core wire will wet to get a solid connection.

CLR might work but I don't have any on hand and I don't know what's in it. I always have salt, vinegar and bicarb- and bread, wine...

Try using ear wax on the belly.

Edited March 17, 2013 by Willoughby Z