I have read the archives about the IVR. Though it "might" be bad I don't think it is the root of this problem.

I bought this truck used about a year ago and drove it little. Always seemed to start and run when I needed it though.
It has been "worked?" on a lot and there were vacuum lines and wires loose or missing under the hood.

I started using in more and developed a leaky radiator. So I replaced it with a new one. Irrelevant to this problem, but for sake of the entire history.

Now, after many hours of troubleshooting and asking other people I know here is what I have.

Replaced: Voltage Regulator (twice because I'm hard headed), electronic ignition module, alternator.

Battery checked out ok.

When started and running without any accessories on it runs fine and voltage at the battery terminals is 14.8V If wipers or lights are turned on the voltage goes to or near 18 volts. Temp. & oil pressure gauges go all the way to the right. Fuel gauge seems to work ok.

The wiring diagram I have does not match up to the way the voltage regulator and alternator are connected. So if someone has a clue how these are supposed to be wired that would help. The diagram did show that the stator wire should go to the choke heater (my stator wire was dangling without a connector and the choke heater had a pigtail without anything connected) so I connected them. No change. The "S" connection from the voltage regulator appears to go through the firewall in a harness on the passenger side. I am at a loss there. THere was also a rather "roughed up looking connector on a wire from the electronic ignition module that was near the choke heater, that was not connected.

BTW: I did replace necessary vacuum hoses and plugged up all the unused ports. Amazing how much better it runs now. :-)

Thanks for ANY pointers.

 

Pull the altenator and have it checked. The only thing I know that would let it overcharge would be a bad diode in the altenator.

 

[updated:LAST EDITED ON 16-Apr-02 AT 08:49 PM (EST)]I think you may have a bad connection at the "a" terminal on the regulator or a bad connection at the starter solenoid post where the "a" wire connects. The "a" wire is what the regulator uses to monitor what the system voltage actually is. The regulator takes the info from the "a" wire and varies the current on the "f" wire which varies the output of the alternator. If the regulator was getting a false low reading on the "a" wire, then it would cause the alternator to put out too much to try to bring the system up. This will also boil the water out of your battery if you drive it too much this way. Just a theory. See if you have good connections and scrape them clean.

Just thought that maybe a bad ground connection in this area might be a possible cause too.

 

Thanks for the replies so far.

I did have the alternator tested and it checked ok. Being skeptical and at a loss I replaced it anyway.

>>I think you may have a bad connection at the "a" terminal on the regulator or a bad connection at the starter solenoid post where the "a" wire connects.
<<

I think this is what I needed to know. I have a background in electronics but could not figure out where the feedback loop started.

I'll check this in the morning. One thing I did notice though was that only one of the posts on the starter solenoid had a wire on it. I thought this was odd but did not find anything dangling from a harness nearby. Toubleshooting things that have been "worked?" on can be very interesting sometimes. :-)

 

Ok, getting nowhere fast I'm afraid.

Since the wire to the stator on the alternator was just lying loose, can someone tell me where it should go?

If I put an ammeter inline between the "s" connection on the voltage regulator and the stator connection on the alternator it reads around 30A (digital ammeter rated at 10A) so it may not be accurate but it certainly isn't right.

Thanks

 

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Tim, My wire from S looks like it is going to my electric choke, i'll double check to be sure. ( Kochy54 - Charging/Battery Problems)
-Carl

 

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This would be the connection diagram if you have an ammeter in the dash. The wiring for a idiot light is different. I posted this because it labels the reg terminals.