More Electrical/Idle Problems

[icejawa]

Did anyone suggest checking the alternator? It seems that the alternator cant keep up so it may be deficient.

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Right, that's what I was assuming at one point. May as well get one and a new alt harness to go with it. Either way once all the electrical crap is sorted out the car will run better than it ever has in the past 20 years

 

[tony-muscle]

Did anyone suggest checking the alternator? It seems that the alternator cant keep up so it may be deficient.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Right, that's what I was assuming at one point. May as well get one and a new alt harness to go with it. Either way once all the electrical crap is sorted out the car will run better than it ever has in the past 20 years

Do the 3G altetnator conversion while you are at it. I have a post with what i did based on another post that had a good explanation of parts to use. Let me look it up and i will post the link.
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[tony-muscle]

Did anyone suggest checking the alternator? It seems that the alternator cant keep up so it may be deficient.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Right, that's what I was assuming at one point. May as well get one and a new alt harness to go with it. Either way once all the electrical crap is sorted out the car will run better than it ever has in the past 20 years

Do the 3G altetnator conversion while you are at it. I have a post with what i did based on another post that had a good explanation of parts to use. Let me look it up and i will post the link.

Sent from my SAMSUNG-SM-G930A using Tapatalk

This is the post I was referring to: 

https://www.7173mustangs.com/thread-3g-alternator-upgrade-wiring-question

 

[midlife]

Did anyone suggest checking the alternator? It seems that the alternator cant keep up so it may be deficient.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Right, that's what I was assuming at one point. May as well get one and a new alt harness to go with it. Either way once all the electrical crap is sorted out the car will run better than it ever has in the past 20 years

Do the 3G altetnator conversion while you are at it. I have a post with what i did based on another post that had a good explanation of parts to use. Let me look it up and i will post the link.

Sent from my SAMSUNG-SM-G930A using Tapatalk

I'd advise against that, at last at this time for a couple of reasons.  One, it will complicate the finding of root cause if it is not the alternator.  The 3G requires significant rewiring of the alternator harness.  Secondly, it will cause the ammeter gauge not to function any more, which is Icejawa's only signal of how things are going on with charging.

Usually, MSD systems require a full 12V to the coil, so that might be one of your problems.  But first, let's just change the alternator to a rebuilt replacement from Autozone or where ever.  It does sound a lot like your battery is not being adequately charged.  When you goose the gas, does the ammeter needle go to center or to charge at all?

 

[icejawa]

What amps alternator would you recommend? I can't test the ALT gauge when I floor it half way right now because the jealous neighbors would probably call the cops on me (houses are really close to each other). I will be sure to do it tomorrow though

 

[midlife]

If you are replacing the alternator and harness, I'd get the 60 amp (stock) version for your 71. 60 may not be enough with halogens. I'd get the harness first, and go to Autozone and see if there's a larger capacity alternator that would fit your harness.

 

[icejawa]

If you are replacing the alternator and harness, I'd get the 60 amp (stock) version for your 71.  60 may not be enough with halogens.   I'd get the harness first, and go to Autozone and see if there's a larger capacity alternator that would fit your harness.

ah ok sounds good. I'll see if they have one in stock tomorrow. Ever since chasing this problem I've been compulsively buying parts every day in preparation for upcoming car shows.

 

[Fabrice]

I've once had to buy 3 batteries at gas stations to get back home at nite because of a defect alternator. As long as there is sufficient power, all runs/works ok with no alternator. So to me, before hurting the mastercard again, I'd first disconnect it to see if it actually generate a prob. As its a garage condition, you can rule that prob out in 5 minutes. I also consider look at the battery and even if charged if its having enuff amps. I run 70 amps batt, Look at the release date. If you have low temps in your area, while most start degrade fast after 5 or 6 years in daily use conditions, in cold weather and extended periods of time with no use/recharges, their lifetime reduces big time.

All this to say +1 to Randy to wait change charging harness before having the gremlin identified. And again, I'd replace these halogens with the lowest wattage bulbs I could find.

As a side note, it amaze me reading you saying, "ordered this/that" and next reply say its installed. I just waited 6 weeks to finally get my door hinges pin kit...

 

[Don C]

Check the battery voltage with everything off and then with the headlights on. A battery with a bad cell can show 12 volts with no load and 10, or less, with a load.

 

[icejawa]

I got the new alternator but while taking the old one out I got distracted and forgot which connector of the harness goes where on the alternator. I tried looking it up but I can't find anything online that looks like my harness.

Actually that would explain why I'm having trouble wiring the alternator to the regulator, the stator wire is broken off and 1 connector is completely missing. Good thing I ordered a new harness. Could this be the cause of all the problems? I think this would mean that my car was running purely off of battery power? I also ordered a new voltage regulator because the one in there now possibly could've been damaged by the ghetto rigged wire setup

 

[Don C]

When you have factory gauges (oil pressure, temperature, ammeter) the stator terminal is not connected to the voltage regulator, only when you do not have factory gauges.

 

[icejawa]

When you have factory gauges (oil pressure, temperature, ammeter) the stator terminal is not connected to the voltage regulator, only when you do not have factory gauges.

I have a separate connector coming from the positive choke terminal, would that go on the stator connector on the alternator then?

 

[Don C]

That depends, if it is the original carburetor, yes.

The stator terminal does not supply 12 volts, only around 6 or 7. So, if you have an aftermarket carburetor, connecting it to the stator terminal will still work, but open the choke slower.

 

[icejawa]

That depends, if it is the original carburetor, yes.

The stator terminal does not supply 12 volts, only around 6 or 7. So, if you have an aftermarket carburetor, connecting it to the stator terminal will still work, but open the choke slower.

That explains the choke opening slow. The previous owner had it wired to the stator terminal. It is an edelbrock 1406. What a mess.

 

[Don C]

It is desirable to supply 12 volts to the choke only when the engine is running. If it is connected to a keyed source whenever the key is on the choke will begin to open.

There are a couple of ways to provide 12 volts to the choke only when the engine is running. One is to use the stator terminal as a signal source to a relay. The power lead of the relay would be connected to the battery side of the solenoid. The other way is to connect battery voltage through an oil pressure switch, which makes connection when the engine is running. Both types of choke power must be fused.

 

[Jeff73Mach1]

You mentioned a yellow wire and a connector a few pages ago-I think I may know part of your car's electrical problem.

The Yellow wire is most likely the fusible link. When it burns out none of the electrical system gets power.

I would open up the harness for the wires coming off of the solenoid and try and follow that wire. I suspect you will find a repair that isn't right.

Proper repair for the burnt fusible link is to crimp a fresh fusible link in place (rather than solder it) I don't think this is your sole issue-but I do think it bears closer examination-ask Midlife if I am off track here

 

[icejawa]

Is that wire part of the headlight harness or the dash harness? Or would it be the alternator harness?

 

[midlife]

Is that wire part of the headlight harness or the dash harness? Or would it be the alternator harness?

The fusible link is on the headlight harness, and I did check it out thoroughly.  That is not Icejawa's problem: the car can start and supply power.  Voltage drops when excessive load is placed on the system suggesting either the alternator is not working correctly, not enough power out of the alternator, or a bad splice somewhere in the underdash/headlight harness combination that has excessive resistance.  I do check end-to-end for resistance, so I suspect the problem is on the alternator's side of things.

I could be wrong and the harness at fault; but we need to rule other possibilities out before coming to that conclusion.  I'll be more than happy to make things right.

 

[Fabrice]

I wager $10 on the headlight bulbs.




so I suspect the problem is on the alternator's side of things.

And the $10 winner is? 

@icejawa

From past replies, I see attention goes to alternator and its harness. You did not answer a few questions that were open here (may be via PMs)

Have you have tested the battery, tried alternative to your halogens yet, are these candidates ruled out already?

 

[icejawa]

I wager $10 on the headlight bulbs.




so I suspect the problem is on the alternator's side of things.

And the $10 winner is? 

@icejawa

From past replies, I see attention goes to alternator and its harness. You did not answer a few questions that were open here (may be via PMs)

Have you have tested the battery, tried alternative to your halogens yet, are these candidates ruled out already?

I agree the problem can't be with the harnesses Midlife gave me, they're pretty damn well done and the symptoms point to the alternator or its harness as you guys pointed out.

I have tested the battery and its good, the only alternative to halogens I have is a relay harness that goes between the original headlight harness and the bulbs. The alternator harness was pretty mangled and for some reason the one I ordered is on backorder. I bought a new alternator but I need to wait for that harness