PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   68-69 GTO Tempest & LeMans TECH (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=433)
-   -   Mystery wire and white smoke (https://forums.maxperformanceinc.com/forums/showthread.php?t=868139)

Vid 07-23-2023 11:58 PM

Mystery wire and white smoke
 
Finally got ready to turn the key on the new motor. Bumped the starter and spotted white smoke from the voltage regulator/distributor area and shut it down immediately. Smoke was coming from the harness that connects to the voltage regulator. There is a wire (circled in yellow) that I could have sworn was grounded to one of the VR mounting bolts. I disconnected it from the ground bolt and no more white smoke. Is this a hot wire used for electric chokes? Tomorrow I’m going to take off the wire covering and investigate closer. https://uploads.tapatalk-cdn.com/202...9ca4357400.jpg
https://uploads.tapatalk-cdn.com/202...ab84686bc5.jpg
https://uploads.tapatalk-cdn.com/202...f2a55c4acc.jpg


Sent from my iPhone using Tapatalk

Scott Thelander 07-24-2023 03:28 AM

That sure looks like a coil power wire clip

Vid 07-24-2023 10:13 AM

Quote:

Originally Posted by Scott Thelander (Post 6441960)
That sure looks like a coil power wire clip


Ah! Leftover from the HEI conversion probably?


Sent from my iPhone using Tapatalk

Scott Thelander 07-24-2023 11:47 AM

10-4

Vid 07-24-2023 12:32 PM

Quote:

Originally Posted by Scott Thelander (Post 6442006)
10-4


Could I hijack that wire for my electric choke? [emoji2369]


Sent from my iPhone using Tapatalk

tekheavy 07-24-2023 01:24 PM

Quote:

Originally Posted by Vid (Post 6442016)
Could I hijack that wire for my electric choke? [emoji2369]


Sent from my iPhone using Tapatalk

Not if it's a resistor wire. Take a volt meter and make sure you are getting a full 12 volts.

Vid 07-24-2023 01:27 PM

Quote:

Originally Posted by tekheavy (Post 6442027)
Not if it's a resistor wire. Take a volt meter and make sure you are getting a full 12 volts.


Roger that.


Sent from my iPhone using Tapatalk

Shiny 07-24-2023 01:52 PM

Good thought on the voltage drop but only if the wire is connected to the coil.

If the wire is powered but hanging open with no load (as shown in the photo), it will read 12V to ground, whether it's a resistor wire or not.

Current needs to flow in the wire to measure its voltage drop.

Either find the other end of the wire and measure resistance directly or hook it to the coil if you want to use a voltage reading.

How much resistance would it have if it was a resistance wire? What is the load resistance of an ignition coil? The ratio of the load resistance and wire resistance will determine the voltage drop within the wire.

For example, if a coil is a 10 ohm resistive load, and the wire is a 10-ohm resistor, then the voltage with the coil pulling current will be 6V. If the wire is straight copper, then the voltage will be near 12V because all the voltage loss will be in the coil.

Vid 07-24-2023 02:17 PM

Quote:

Originally Posted by Shiny (Post 6442035)
Good thought on the voltage drop but only if the wire is connected to the coil.

If the wire is powered but hanging open with no load (as shown in the photo), it will read 12V to ground, whether it's a resistor wire or not.

Current needs to flow in the wire to measure its voltage drop.

Either find the other end of the wire and measure resistance directly or hook it to the coil if you want to use a voltage reading.

How much resistance would it have if it was a resistance wire? What is the load resistance of an ignition coil? The ratio of the load resistance and wire resistance will determine the voltage drop within the wire.

For example, if a coil is a 10 ohm resistive load, and the wire is a 10-ohm resistor, then the voltage with the coil pulling current will be 6V. If the wire is straight copper, then the voltage will be near 12V because all the voltage loss will be in the coil.


I’ll break out my multimeter and see what I get. The HEI of course has two terminals, which are battery and tach. Should I make the measurement between the open wire and the battery terminal? I just don’t want to fry anything more than I may have already. Sometimes I feel like my electrical ignorance knows no bounds, lol


Sent from my iPhone using Tapatalk

Shiny 07-24-2023 04:01 PM

Quote:

Originally Posted by Vid (Post 6442042)
I’ll break out my multimeter and see what I get. The HEI of course has two terminals, which are battery and tach. Should I make the measurement between the open wire and the battery terminal? I just don’t want to fry anything more than I may have already. Sometimes I feel like my electrical ignorance knows no bounds, lol


Sent from my iPhone using Tapatalk

You're not ignorant. You are smart and cautious, both good things!

If it were me, I'd:

1. First verify the wire is "hot"

Set your meter to measure volts, turn on the ignition and measure the voltage between the open wire terminal and ground.

Don't measure between the HEI battery terminal and the wire.

Measuring 12V between the open wire and a chassis ground will tell you if the wire is "hot" or not but won't tell you if it is intended to be a resistance wire for the original ignition.

Measuring with the ignition switch on and off will tell you if the wire is indeed a source of power for the ignition system, which I think is your goal.

2. Then determine if the wire has high or low resistance

Assuming you confirmed the wire is indeed "hot", I'm not sure the best way for you to tell if it is a resistance wire or not.

It would be easiest for you to tie this to the battery terminal of the HEI and measure voltage with the ignition switch on. I don't see that you could hurt the HEI but I don't know if it will draw enough current without the engine running to determine if the wire has resistance.

Others with direct experience can tell you this and I'm sorry I cannot.

I personally would get a resistor, like maybe 10 or 20 ohms and connect it between the wire terminal and ground, then measure voltage. But I have this stuff laying around.

If you aren't comfortable with any of this, don't be afraid to ask for more help. There are many on here with more experience that can probably give you better advice.

Mike

Greg Reid 07-24-2023 04:09 PM

If I recall correctly, I think the ignition resistor wire only drops about 3 volts. It would probably be ok for your choke. At the very least it wouldn't hurt your choke and you could also read the voltage there which would answer the question about how many volts are being dropped.

Vid 07-24-2023 04:17 PM

Thanks Mike, Greg and everyone for your assistance. I’ll keep you posted on my progress.


Sent from my iPhone using Tapatalk

Shiny 07-24-2023 04:56 PM

Quote:

Originally Posted by Greg Reid (Post 6442068)
If I recall correctly, I think the ignition resistor wire only drops about 3 volts. It would probably be ok for your choke. At the very least it wouldn't hurt your choke and you could also read the voltage there which would answer the question about how many volts are being dropped.

Good idea and agree it will be safe to hook it up.

I'd still confirm it is "hot" and understand "when" it is hot before looking at the voltage drop.

Mike

Greg Reid 07-24-2023 05:19 PM

Quote:

Originally Posted by Shiny (Post 6442083)

I'd still confirm it is "hot" and understand "when" it is hot before looking at the voltage drop.

Mike

Absolutely. First things first.

Vid 07-28-2023 07:39 PM

So to follow up, the resistor wire was 3 volts and works ideally for the electric choke. Got my wiring woes handled. Thanks again, what would I do without you guys [emoji2369][emoji3526]


Sent from my iPhone using Tapatalk


All times are GMT -4. The time now is 09:37 PM.