I have a '99 FRC with an odd battery draw issue, plus I also can't seem to get rid of the P1637 code - possibly related?. It has LG long tube headers so no, I have not yet got at the starter solenoid connections to clean them.

After reading many post and procedures this is what I have done so far. Removed the Red battery cable at the alternator positive post (insulated the end) and ran a new 4ga cable between the alternator positive post and the main positive feed to the fuse/relay center in the engine compartment. Removed, disassembled cleaned and reinstalled the ignition switch. There is no voltage difference between the battery positive and the D terminal red lead at the alternator plug. With the car in sleep mode, I hooked up my digital meter in series between the battery negative post and the negative battery terminal. There is a 1.96 Amp draw. One by one I removed every fuse, circuit breaker and relay in the fuse/relay center in both the engine compartment and in the passenger compartment located in the passenger foot well. I was never able to identify which circuit had the amperage draw. Very odd. So I removed the three battery cables at the main positive post on the fuse/relay center in the engine compartment and tested them one by one. First the added 4ga cable from the alternator positive post, zero Amp draw. Next the factory Black cable, zero Amp draw. Then finally the factory Red cable which had surprise 1.94 Amp draw. First clue. Now this Red cable goes down to the starter solenoid. Also on that starter solenoid post is the Red factory cable that goes up to the alternator positive post (but on mine its disconnected and insulated). Then there is the Red lead that goes up to the D terminal that plugs into the alternator, but even after I unplug that connector at the alternator, the 1.94 Amp draw is still there.

So my conclusion is that there is a short of some type with the starter solenoid. The car continues to start without much drama as long as the battery is kept on the battery charger. But with that 1.96 Amp draw, if I don't keep the battery charger hooked up, the draw will bring the battery voltage down from 12.75 volts to 11.80 volts overnight.

I ordered a new Ac/Delco starter with solenoid and do not relish the fact that the car will have to go back on the QuickJacks for the third time this month and that I will have to loosen up the passenger header and move it out of the way to replace the starter.

Thoughts, possibilities, feed back or any other ideas? TIA

 

Is it possible that inside the solenoid end piece where all the wires connect there is fine copper residue that is causing the current draw? Very strange problem, and I guess you will find out when you replace the starter.

 

Yep, this definitely seems like the solenoid is junked or something else in the starter area is busted. You have done a great job doing diagnosis instead of guessing and throwing parts, so kudos there. I think that as you replace the starter, you'll find the exact problem. Keep us posted.

 

Did you try disconnecting the wire from the starter to make sure the draw went away? This is a search I'm about to embark on myself, tired of the battery killing itself.

 

​​​​​​The new starter is supposed to be here tomorrow. I am out in the garage right now getting she back up on the QuickJacks. Not sure I will have time to get the header out of the way this evening, but that is the plan. As long as my wife does object too much to me spending even more time in the garage with "the other woman" in my life 😉

 

I know what you mean, I bought a 1937 Plymouth 2dr last year, I refer to her as my new old misstress, or old new misstress 😆

 

Okay, I got the header out of the way and got the starter out of the car. The terminals do not look horrid (bad angle in the picture), but they are not perfectly clean either. Truthfully about what I had expected for an almost 24 year old car that hibernates in the winter and spends most rainy days in the garage. I tested the Red positive battery cable for resistance with my new meter. Measured the resistance between the starter solenoid terminal and the side post battery terminal as well as the terminal at the main positive post on the fuse/relay center in the engine compartment, all the results are 0.00 Ohms. So the Red cable itself seems to be good. I will brush and wipe down the terminals just to be safe side

Not sure how old the starter is but the solenoid doesn't look factory fresh. Not sure how to test this other than take it in and have someone perform a load test on it. But the new starter should be here tomorrow and that is what is getting installed. Hopefully that will solve the parasitic Amp draw.

 

By the way the three year old Group 78 AGM battery was down to 6.1 volts and 31 CCA after being subjected to this parasitic draw for about 6 week without the battery tender being hooked up. So after some research about bringing back a severely depleted AGM battery and watching some very good videos on YouTube, I purchased a new Solar battery tester and new digital 16 Amp battery charger. I had kept the now seven year old wet cell Group 78 battery that I had removed from the car and had saved it for emergency use. So I charged the wet sell up to 13.1 volts and it tested at 569 CCA vs the original new rating of 800. So it continues to earn its place on the shelf as an emergency back up. I then hooked up the depleted AGM battery in series with the charged wet cell via booster cables and hooked up the battery charger to the wet cell. I set the charger to AGM flat plate (the design of the Group 78 AGM) and selected the 8 Amp setting. I checked on things every hour. After three hours I tested the AGM. It was slightly warm to the back of my hand and was up to 11.2 volts and tested at 269 CCA vs an original 740 CCA rating. I set the wet cell battery aside along with the booster cables, and then hooked the charger up directly to the AGM battery and left it at the 8 Amp setting. 15 hours later the charger read Full and had automatically shut off. I tested the AGM battery and the voltage was 13.1 volts and tested at 647 CCA vs the original new 740 CCA rating. I consider that an EPIC success. Is the AGM as good as new, no but it should still have a few years left in it and considering the replacement cost of well over $200, it was well worth the effort.

 

Got the new Ac/Delco starter installed and wired up. Before reinstalling the header and buttoning her up, I doubled check the amperage draw. Now at first I wasn't sure, but then remembered what Bill Curlee said that you had to be patient and wait maybe 90 seconds or more to allow the car to reenter sleep mode. It didn't help that I only had one alligator clip end. But in the end it looks as if the new starter (and/or solenoid) solved the high Amp draw issue. Oh and when I reinstalled the AGM Group 78 battery that had been sitting quietly for more than a day it read 12.7 volts and tested at 737 CCA out of the original 740 CCA rating. Not too shabby at all.

Many thanks to all, especially Bill Curlee for all he excellent writeups and replies over the years.

Now back out there to finish buttoning her up and maybe take her out for a test drive later.

 

Nice!

 

Update: Since in the original post I also noted that I was having an issue with the P1637 code, I thought I would follow up on that as well.

I had disconnected the factory battery cable for the alternator positive post, that runs up from the starter solenoid and insulated the end. I then run a new 4ga battery cable from the alternator positive post directly to the main positive terminal on the fuse/relay center in the engine compartment - no change. I had to replace the starter/solenoid, so I cleaned all the terminal connections at the solenoid - no change. I even pullled the ignition switch, cleaned all the contact and reinstalled it - no change. I researched replacing the alternator with a new and correct Valeo unit, but the best price was +$325 plus shipping & tax. So I then researched trying to buy just a Valeo voltage regulator, which does not seem to be sold separately any more. That seems very odd and makes you wonder who is suppling the voltage regulator in those new Valeo alternator. Anyways, I then tried buying a replacement voltage regulator and had a hard time finding anyone that offered a replacement unit. I finally found Maniac Electric Motors in Dallas TX on-line and ordered a WAI/Transo #M530 replacement voltage regulator for $28 shipped. The US applications is noted only for the C5 Corvette with the 110 Amp alternator. I watched a YouTube video on the C5 110 Amp alternator voltage regulator replacement - its a simple and straightforward procedure. Based on the date codes on the Valeo voltage regulator, mine was a factory original unit with 82K miles. The bushes were well warn and one was sort of sticking. The bearings seemed fine in my factory alternator, so I hoped the diode bridge and stator windings were also fine. I lightly cleaned up the bush contact areas on the armature shaft with 2000 grit sand paper (finest grade I had on-hand) and clean up all the brush dust with electrical contact cleaner. I even removed and cleaned the silicone dust washer that protects the bearing . But I made sure to keep the solvent from getting into the bearing itself. I cleaned up the terminal contacts and used high temp RTV to reseal those terminals. Before reinstalling the alternator, I tried cleaning up the area in the engine compartment around the alternator that seemed to be coated/caked with alternator bush dust.

After reinstallation, I cleared the codes and fired her up. No more P1637 code! Its been running fine over the weekend. I really do NOT miss the "Service Vehicle Soon" statement on the DIC every time I turned the ignition On or Off. Not sure what others have experienced with the WAI/Transpo #M530 voltage regulator or if it solved their P1637 problem. I really wanted to keep the original Valeo alternator if at all possible (especially after reading all the issues other's have experienced when replacing their's with a non Valeo unit) and I am hopeful that this is truly a long term fix.

As always YMMV.

Below are pictures of the suspect original Valeo voltage regulator, the cleaned up original Valeo alternator and the new WAI/Transpo #M530 voltage regulator installed on the Valeo alternator. I forgot to take a picture of the WAI /Transpo #M530 voltage regulator, but found a picture of it on-line. As you can see, the Valeo analog transistor has been replaced by what one would have to presume is a digital circuit design that is mounted to the inside surface of that large aluminum heat sink.

 

Thank you for posting detailed, excellent updates. Really fantastic.

 

One last update, everything was fine with the alternator until late last driving season when I started getting a different alternator fault code after 3 years. So this time I just ordered a new real Valeo #439217 from RockAuto and finally got it installed today and it solved that issue. Keeping the old unit for a weight on the shelf or a door stop.