: 71 Deville was running fine now DEAD

12-17-09, 11:20 PM
Started her up for the 1st time in a week, it was about 20 degrees out this afternoon. Ran fine but after a while the GEN light came on. I was about 7 miles away from home when this happened so I just drove it home and parked it. Everything was working just fine. Now when I go to start it its DEAD. Won't even think about cranking no clicking nothing, lighs and radio powers windows horn etc all work but not the starter. There was a wire that looked like it was coming apart, it ran off the alternator to a buinch of wires going towards the back of the engine on the passenger side, I replaced the wire and still nothing, not even with a 50 amp jumper box on it. The thing that gets me is the meter on the jumper box doesn't move when you turn the key either, so I believe the starter has no power going to it. But why would that cause the GEN light to come on? What should I inspect/test? I know how to test the batt but how do I test the alt? There were no problems leading up to this, the car has been just fine! It's sitting on the street, would like to get her back in my garage! Any help GREATLY appreciated! Thanks!

12-17-09, 11:21 PM
Forgot to mention its a coupe, with a 472.

12-17-09, 11:38 PM
Well, whenever dad and I ever had to test alternators in a hurry, we just took them off and ran down to AutoZone or Advance.

12-18-09, 12:18 AM
Sounds like a bad starter solenoid. They can fail without warning.

12-18-09, 12:43 AM
alternator. 7 miles with no charge is a long while, I know you had the heat on too. If the battery isnt getting a charge, it may be gone also.

12-18-09, 12:52 AM
^ Get it tested. And if your battery has a warranty, get it replaced to air on the safe side anyway.

12-18-09, 04:36 AM
Like I said though, when I turn the key there is no draw on the battery, the gauge on the jumper does not move at all and nothing clicks or makes any sound whatsoever. The battery also does not have much of a draw on the charger, I would think it would draw more than 3 amps if it was dead, last dead battery I had was drawing 12 amps. I've had autozone tell me my alt is fine when it was in fact dead thats why I asked how to test it myself if that is possible. Thanks for the suggestions, would the starter solenoid cause a GEN light and make my car not even think about turning over? And so suddenly? I'm assuming it's located right on the starter, how can I test it? I have another battery in my truck that I will try later today to verify the batt is not the issue. But if it's not what do I test/look for? These Minnesota winters are so ROUGH on cars I tell ya!

12-18-09, 09:17 AM
could be both the alternator and the starter solenoid died at the same time, maybe even related to eachother?

Get them both checked

12-18-09, 10:10 AM
I dont think you can test an alternator at home with regular tools, I think they have to hook it up to a machine. But I believe you can test to see if the starter solenoid is getting power to it. It could also be a bad connection at the battery, alternator or starter. But I believe the alternator or the connections to it are the only thing that will turn on the GEN light, especially if you have a different light for battery. During that 7 miles with the GEN light on, your battery went completely dead so either the alternator didnt charge it, the battery went out while driving or the connections went bad. I would take the alternator to get tested as a starting point, its easy enough to take out. But i believe Dope had a similar problem when a fuse was bad, or was it a dummy light that burnt out on him?

12-18-09, 11:49 AM
If you don't trust them running the test, sometimes you can hook it up to the machine yourself and do it. All depends on the person working at the store. :thumbsup:

12-18-09, 05:51 PM
I did a search to see if anyone else had this problem and what they did to fix it. Some said to see if the "Trans" fuse was blown. I checked and sure enough it was. Put in a new fuse and still no help, come to find te new fuse blew right away when I turned the key! I get a very very dim GEN light when I turn the key to the on position, noting else though. So I'm assuming its a bad wire, Where to the wires for the "trans" fuse go? Anyone know the colors/locations?

12-18-09, 08:48 PM
Check your battery ground. Run a voltmeter from the frame to battery positive terminal. You should get the same reading you get from the negative terminal to the positive terminal, which will be your battery's state of charge. If you don't get a reading, Your ground cable is suspect. Your alternator and solenoid should be alright.
Check the connections at your solenoid. All connections for your vehicle's operating circuits stem from this point.
Check the connections of the ground cable from your starter to the frame.
The fact that your power windows and seat work suggests you possibly have enough connection to sustain 30 amps. your starter can draw 60 amps or more on initial activation.

12-19-09, 12:43 PM
Might be a long shot considering your car is different to my '91 but I just had a similar thing happen. Started the car first click, drove 200 meters from home and idled over a speed-bump. Suddenly the engine stalled.
The symptoms were like you describe. All electrics seemed to work until the key was turned to the start position, then nothing. A battery boost resulted in the same thing so I got the car towed to my garage. It tuned out to be a seized Alternator. Basically, while the drive belt was on, the engine could not crank. My mechanic took the belt off and the car started no problem.
He showed me the old Alternator and I could barely turn it. With belt tension on the bearing it was effectively solid.


12-19-09, 01:19 PM
Check the alternator of course, but also find out if your battery is toast or not. Sounds like a battery/alternator problem though.

12-19-09, 04:32 PM
Thanks for the suggestions, but my question now is why would that fuse keep blowing? doesn't make sense to me

12-19-09, 04:35 PM
And if the battery really is dead I would still think it would at least try to do something with the 50 amp jumper hooked up.

12-19-09, 05:54 PM
A battery can die beyond charge but theres gotta be a way you can test to see if the solenoid is getting power, from the battery and ignition wire. Maybe an ignition fuse, maybe the trans fuse is ignitions related.

12-19-09, 09:41 PM
The fuse is blowing because you have an open somewhere in the circuit it controls. I don't have a 1971 FSM so I can't look up your specific configuration, but the 1969 FSM gives instruction on how to test current for the starter solenoid. I suspect the solenoid as the issue because I've had this happen on my '77. You turn the key to ON, and everything is fine, all the accessories work, the lights are bright, etc. Turn the key to START, and everything dies, no cranking, nothing. Release the key back to ON, and all the electricals come back. Replacing the starter solenoid solves the problem.

12-20-09, 04:56 PM
1973 was the first year of solid state alternator, with regulators inside the alternator itself. 1971 472s still had a separate voltage regulator on the firewall, which is why I believe it's still called a generator and not an alternator.

It sounds like you may have blown the regulator, which led to a few other problems, possibly blowing the starter solenoid. You should always change the regulator with the generator, so be sure you buy one and replace them both. Also, give the fuse panel a good look to ensure you didn't surge any fuses. If you change them both and you're still not able to start the car with a jump box, it's time to check the starter solenoid. Another check is the connection at the starter itself to make sure it's nice and clean (tough to have in the great white north).

12-20-09, 09:46 PM
Today I went out and brushed the snow off my car, got out the multimeter and tested at the batt terminals, 12.6V. Tested with positive on batt and ground on body, 12.6V. Ground on batt and ground on body both gave me a reading of 12.6V when I put the positive on the alt. The solenoid requires me to get under the car to test and its currently in the street so I will move it and do so tomorrow. For the hell of it I took a known good battery (one in my daily driver) and tested it, 12.6V, then put it in the car and it did not help anything so the batt I have is still good. The only dash light that comes on when I turn the key is the GEN light and it's barely on, at night you can barely see it, in daylight you cant. No other warning lights come on like they usually do when you turn the key. Where is the regulator? I did not see anything in the fenderwell but there was a box about 3" by 1" (give or take) with I believe 4 wires coming out of it on the passenger side near the firewall by the AC lines. Alot of other people I talked to said I should try the solenoid, but the thing that confuses me is the TRANS fuse keeps blowing. The second I turn the key I hear it go POP! I also inspected all the wiring that I could see under the hood and there are no open melted or damaged wires. Any other suggestions?

12-20-09, 10:34 PM
That box you spotted is the voltage regulator. If it's gone bad, that might explain your current surge blowing your fuses. However, I still think the starter solenoid is the root of your problem.

12-21-09, 02:39 AM
The only fuse thats been blowing is the TRANS fuse, all the rest are fine. I will check the solenoid in the morning. Thanks again for the suggetions!

12-21-09, 04:50 PM
The trans fuse may be related. I don't know if the kick down switch is on the carb or on the accelerator pedal bracket but I would look closely at those wires and if nothing looks obvious I would unplug it temporarily to see if it stops blowing the fuse. Since you have the multi meter you can check the starter wiring and see if the solenoid is getting voltage while somebody turns the key, if so then you have a solenoid/starter problem. Those starter wires may be grounding on something too causing the faint gen light

12-22-09, 12:27 AM
Today I econnected the battery and just for the heck of it I turned the key, it started! I got it into the garage and checked voltages again, with engine OFF the batt was reading 13.2V after about 10 min of the engine running and warming up. Then with the engine RUNNING I got a reading fluctuating between 14.9 and 15.4 volts. I still have a dim GEN light when I turn the key to the ON position, and when the car is runnung I have a bright red GEN light. Now I'm thinking I'm getting a overcharging condition because the voltage should be more around 14V with the engine running, right? Would this be the fault of the regulator or the generator itself?

12-22-09, 12:35 AM

12-22-09, 07:30 PM
Your 100% sure its the generator?

12-22-09, 09:41 PM
[ Where to the wires for the "trans" fuse go? Anyone know the colors/locations?[/quote]

I don't have my manual here, but I think it is for the kick down solenoid in the transmission. Wire goes down the back and to the left side of the trans to the solenoid.

12-22-09, 10:08 PM
Then with the engine RUNNING I got a reading fluctuating between 14.9 and 15.4 volts. I still have a dim GEN light when I turn the key to the ON position, and when the car is runnung I have a bright red GEN light. Now I'm thinking I'm getting a overcharging condition because the voltage should be more around 14V with the engine running, right? Would this be the fault of the regulator or the generator itself?

You might take your car to a mechanic who can test your battery's electrolyte specific gravity or you can run down to NAPA and buy a tester. With that much fluctuation you may have a temporary internal short within the battery caused by plate degradation.
15.4 is a high rate for output once the engine is warmed up, but it proves that your alternator is working. Rate should be around 14.2 - 14.6. Sure you aren't running anything extra?
There is a couple other things which may be affecting your alternator. If there is shiny material around the front of the alternator, your front bearing may be on the way out.
The last thing could be that your brushes have worn to the point where your brush springs aren't allowing the brushes to maintain contact rotor rings.

The regulator, if it is the box you describe, should be approximately 3"x3". These units will screw up and cause overcharging. You can open the box and check the points. They can be cleaned, if they aren't burned real bad by running a dallor bill through the points. If they have heavier burn, sometimes you can hit them with a jeweler's file to clean them.
Make sure someone hasn't put a later style alternator on your car. Yours should be the earlier S1, S2 design.

12-23-09, 11:42 AM
Well, I don't have the tool you describe for the battery, but I have 2 other betteries that will fit in the car so I will try another one and see what my readings are and if they fluctuate. A new regulator is $11 at NAPA so If I open mine up and it looks bad I'll just replace it. The generator looks quite old, maybe even original to the car. It has a 2 wire plug-in connecter and has a connecter with a nut that the wire from the batt goes to, and a wire from the engine harness goes to. I believe O'reilly auto tests generators, regulators and such, I think I'll take the generator in and see what they say about it.

12-25-09, 06:40 AM
If you are getting 15 volts then the generator is working fine, must be the regulator.