1969 Imperial charging system

[ImperialLeBaron1969]

Im not shure I got this right, but I hope!

In 1969 Imperial (and mabye some premium Chrysler models) used a new charging circuit with an insulated brush arlternator and a new electronic voltage regulator. Alternator has one batt terminal and one field terminal.

In 1970 all chryslers (at least c-bodys) used an isolated field alternator and the electronic voltage regulator. The voltage regulator in 1969 has a 3 prong connector an the back, a connector in a triangular shape. In 1970 that connector has only 2 prongs. Alternator has onte batt terminal and two field terminals..

The different types of alternators are explained here:

You guys with 1969 Imperials. Have you replaced the alternator and voltage regulator. If so, how did you do it? Is it possible to use a newer isolated field alternator in a 1969 car? The voltage regulator for 1969 with a 3 prong connector is hard to find. Can it be recpaced with a newer one?

My car doesnt charge as it should. It chages on higher rpms, but I dont know how mush. On idle, battery has 12,7 volts.

 

[Big_John]

You guys with 1969 Imperials. Have you replaced the alternator and voltage regulator. If so, how did you do it? Is it possible to use a newer isolated field alternator in a 1969 car? The voltage regulator for 1969 with a 3 prong connector is hard to find. Can it be recpaced with a newer one?

I don't own a '69 Imperial and have never done this, but if I did, I would rebuild the alternator rather than replacing. Alternators are pretty easy to rebuild, especially when they are currently (pun intended) working and not trashed. A simple brush change might help and that's really simple.

If I were to replace with an isolated field, it seems to me that you would have to rewire the charging system to include a '70 up regulator.

But, "hard to find" isn't the same as "impossible to find". You just have to dig a little deeper in your wallet.

My car doesnt charge as it should. It chages on higher rpms, but I dont know how mush. On idle, battery has 12,7 volts.

That is a little low, but how is it with the headlights on? At what RPM does the voltage come up? Condition of the battery? Are you having problems starting the car because of a low battery?

There's some "nature of the beast" going on too as these cars don't charge a lot at idle. What you don't want to do is compare new car specs (like you find on the internet) to your car. You also don't want to start throwing parts at it like some folks will.

What you do want to do is check and clean all your battery connections, including the connections at the starter and engine block. Replace the cables if needed. If there's temporary battery terminals (identified by the screws clamping the cable), like a lot of older cars end up with, replace the cables. All the little things have to work together to make it operate correctly.

 

[CBODY67]

The other thing in any alternator to check is the diodes. Other than that, the shaft bearings. I suspect there might be a Chrysler MasterTech video on these "New for 1969" items at www.mymopar.com .

CBODY67

 

[ImperialLeBaron1969]

I don't own a '69 Imperial and have never done this, but if I did, I would rebuild the alternator rather than replacing. Alternators are pretty easy to rebuild, especially when they are currently (pun intended) working and not trashed. A simple brush change might help and that's really simple.

If I were to replace with an isolated field, it seems to me that you would have to rewire the charging system to include a '70 up regulator.

But, "hard to find" isn't the same as "impossible to find". You just have to dig a little deeper in your wallet.

That is a little low, but how is it with the headlights on? At what RPM does the voltage come up? Condition of the battery? Are you having problems starting the car because of a low battery?

There's some "nature of the beast" going on too as these cars don't charge a lot at idle. What you don't want to do is compare new car specs (like you find on the internet) to your car. You also don't want to start throwing parts at it like some folks will.

What you do want to do is check and clean all your battery connections, including the connections at the starter and engine block. Replace the cables if needed. If there's temporary battery terminals (identified by the screws clamping the cable), like a lot of older cars end up with, replace the cables. All the little things have to work together to make it operate correctly.

Thank you!

I bought the car 3 years ago and I did notice that the speed of the fan was higher when driving than on idle- Power went wings sometimes woomnt operite on idle either, but when driving.

When I measure voltage over the battery, It wont increase at all when lights or Ac is turned on, or when reving. Seems like the system have degraded the last months. I dont drive that much and charge the battery quite often.

The regulator is hard to fint, but I cand find it. NOS and probably beens sitting on the shelf för 40 år 50 yeras. I dont know how bad/god it is.

Your advice to rebuild the alternator seems like the best option for me. And change the regulator if its not working. I checked the cround and connectors. The connector at the generator, BATT, need some work and the nut have rusted. Could be problem as well. thanks!

 

[Big_John]

The connector at the generator, BATT, need some work and the nut have rusted. Could be problem as well.

Very likely it is the problem or at least part of the problem.

 

[ImperialLeBaron1969]

Very likely it is the problem or at least part of the problem.

Yes! Didnt notice that earlier.

 

[ImperialLeBaron1969]

Its somethng wrong with the alternator, the batt terminal gets really hot. It wasnt rust, it looked burnt. I suppose this alternator have been running hot for a while so it could be damaged.

 

[Big_John]

Its somethng wrong with the alternator, the batt terminal gets really hot. It wasnt rust, it looked burnt. I suppose this alternator have been running hot for a while so it could be damaged.

Resistance causes heat. Heat makes things burn and makes the connection worse. The connection gets worse and more resistance is created. Resistance causes heat...........

You may have a bad connection or a bad wire. Doubtful that it's an alternator problem.

I have some procedures for checking the alternator and regulator that have been adapted from the FSM and what my Dad showed me many years ago. I've never tried to figure out how it could be applied to the '69 Imperial. Now I really want to know... LOL... I'll look a little later (busy on my own car, just stopped for lunch) and see what I come up with.

 

[ImperialLeBaron1969]

Resistance causes heat. Heat makes things burn and makes the connection worse. The connection gets worse and more resistance is created. Resistance causes heat...........

You may have a bad connection or a bad wire. Doubtful that it's an alternator problem.

I have some procedures for checking the alternator and regulator that have been adapted from the FSM and what my Dad showed me many years ago. I've never tried to figure out how it could be applied to the '69 Imperial. Now I really want to know... LOL... I'll look a little later (busy on my own car, just stopped for lunch) and see what I come up with.

Yes, it causes heat. I did use my ohm meter and measured 0.6 ohm between alternator batt terminal (did sandpaper before) and the the cable that goes från the terminal. The resistanse from the alternator ground to the ground cable at the battery was even lover.

 

[Big_John]

Yes, it causes heat. I did use my ohm meter and measured 0.6 ohm between alternator batt terminal (did sandpaper before) and the the cable that goes från the terminal. The resistanse from the alternator ground to the ground cable at the battery was even lover.

.6 ohms is too much. You should be 0 or maybe some negligible resistance of under .1 due to your meter leads.

I think the thing to do is measure voltage at those points and compare.

 

[ImperialLeBaron1969]

No wonder that this alternator and charging cirquit is not working! The original insulated brush alternator is replaced with a new newer one, one with a square back and two field terminals. The regulator is also newer and has two wires connected (ignition and one field). One field terminal is connected, it goes to the regulator, the other is not!

Seems like the old system is modifed to use a newer alternator and regulator like the 1970 cars and up.

When i look at the schema above, for alla Chryslers and Imperials from 1970 and up, the other field terminal should connect to ignition, same as one of the regulator connections. But when I look at the car and the generator it looks like a wire missing cause there is a sign of a connector at the generator ground that mabye is for the not connected field circuit.

I dont know what type of electrical voltage regulater that is in the car. There is one available for pre 1970 cars that replaces the old mechanical one. It could be that type that is in the car today.

Is it possible to run an alternator with two field terminals and leave one disconnected as is today? Seems like a bad idea.

Is it possible to make a test and connect the unconnected field terminal to ground? It that doesnt work, I can try to connect the field terminal to Ignition 2 as on the chema above.
Or could I risk to ruin the system? Thanks for help!

 

[Big_John]

No wonder that this alternator and charging cirquit is not working! The original insulated brush alternator is replaced with a new newer one, one with a square back and two field terminals. The regulator is also newer and has two wires connected (ignition and one field). One field terminal is connected, it goes to the regulator, the other is not!

Maybe something has been replaced or changed out, but remember it was working. If you just changed the alternator/wiring/regulator, you could say the problem is the wrong parts, but they couldn't be too wrong if it was working.

When i look at the schema above, for alla Chryslers and Imperials from 1970 and up, the other field terminal should connect to ignition, same as one of the regulator connections. But when I look at the car and the generator it looks like a wire missing cause there is a sign of a connector at the generator ground that mabye is for the not connected field circuit.

That is the circuit you set up to test the charging system with the green wire grounded etc. Just making sure you know that before you decide how your car is wired.

 

[ImperialLeBaron1969]

I havnt done anyting. This was what the wiring was when I bought it 3 years ago. Thats make it more difficult and I need some advice.

 

[ImperialLeBaron1969]

Problem solved. Insulation between alternator body and batt terminal was bad and the batt stud rustad. I got a new alternator with 2 field terminals and grounded one. Now it charges as it should.