bypassing / eliminating factory voltage regulator

[72RoadrunnerGTX]

Have you performed a full field test on that alt with the mentioned loads, at idle? How about checking the voltage drop from the regulator reference to the battery post? Any idea just what amount of current these loads are drawing?

 

[multimopes]

I'm "electrically challenged!" My older brother is/was and electrical engineer. Any problems I ever had and couldn't figure out I' d consult him. I'm also "shift work challenged", "sleep deprivation challenged", "senility challenged" and just plain burned out! I had no electrical woes when I got the car but, as stated, it was formerly used as a race car. The guy I bought it from bought it from the former owner and had it painted and added a few creature comforts,(an aftermarket radio system with power amp) Battery was moved to the trunk for racing previous to that. Car ran fine except the single 16" electric fan without a shroud on a minimal size radiator was useless for street driving, only for 1/4 mile passes. I got a larger radiator with 2 11" spal fans and that helped, but still not enough. I finally bought a 26" radiator with 2 more powerful fans, (the ones in it now). Those fans were too much for the old 60 amp alt which I found had intermittently bad diodes. Only since then have I had this problem. How do you fully "field test" a system that works fine with everything else? One possibility is that my trunk mounted battery (an Optima red cell), is over 8 years old. Maybe it is just run down, (like me). I suppose any connection is questionable and under the dash is a nightmare with old gauges not hooked up and such. Access under there is difficult due to the roll bars coming down both side doors and my increasingly decrepit body. When I got the car, I found several things electrically bad such as wires run through drilled holes in the firewall without grommets, etc. I can't understand how someone who knows how to set a car up for racing could be that stupid. I will be testing the battery voltage today when I get home and look up how much juice those electric cooling fans draw. By the way, there is also a battery cut off switch mounted in the back bumper which evidently was required for what ever class the car ran in on the track. The heavy supply wires run up both sides if the frame. Hot on driver's side and ground up the passenger side. Any suggestions are greatly appreciated and any offers to fix it for me, "paid in beer", are enthusiastically welcomed. Thanx in advance!

 

[multimopes]

Update: I just put a meter on the battery, 12.16 volts. the same when switching on the bumper kill switch, measured everywhere under the hood also. I also consulted the oracle at Delphi and found out my fans pull 20 amps each, 40 amps at idle. Also I found the receipt for the battery and it's almost 9 years old. Haven't done any further tests yet but I found a way to do the load test, no load test and full field test as well. Ran out of time after work today. I think that the battery is getting a little weak.

 

[72RoadrunnerGTX]

Yikes, 40+ amps for fans? I would be hard pressed to expect any alternator to supply that, all other vehicle loads, and maintain full charging voltage at idle rpm. Curious what kind of cooling issue requires that amount air movement while idling.
I certainly would have an older battery tested for a higher-than-normal charging rate.

 

[multimopes]

The radiator is a 26" & was from SpeedCooling and is a step up from the 22" that was in there. The other fans were only 950 cfm each & these are 1500 cfm each. The original alt went south so I put the 95 amp Power Master in. One of the contributing factors to the fans kicking on, one first not both until we get up to full temp is my Derale fan controller went bad and is unreliable. I don't trust what my temp gauge reads either. I have a new fan controller that is more adjustable but haven't yet found the time to install it. I went searching for my amp probe this morning and then I remembered someone borrowed it a few years ago and I don't remember who. I think one of my brothers. I will check tonight. I also have a 440 source aluminum high flow water pump housing to go with my 16 blade high flow aluminum water pump. Once again, not much time with the normal chaos in my life. Then there is my next project, replacing my 3.91 sure grip with a 3.23 sure grip. Then the speedo gear. then a slower pace may eventually set in and I might be able to actually cruise the interstate at 65 without revving the hell out of my engine. Actually, 40 amps ain't out of the ball park. I was trouble shooting my brothers PT Cruiser temp problem and it has a 2 speed electric fan. The fuse for it is 40 amps!
There are supposed to be alternators out there that can deliver full output at idle if needed. One guy here is using one of those and they are internally regulated. If I remembered how many amps my fans pulled, I would have mentioned it to sales clerk. He might have said their unit couldn't provide that much but I get the feeling that he really didn't know.
By the way, I want to thank you guys again who are guiding me with this little project. I wish I could just say to some shop, "fix it please" but I really want to do it myself.
To be continued.............................

 

[multimopes]

Update: I called Tuff Stuff and told them about the 40 amp draw and the guy sounded skeptical that the unit could put out that much at idle. He did ask me to try installing a new voltage regulator so I bought the "top of the line" from Napa. It's from the Chineseum of course. Well, didn't make any difference and maybe even worse. At startup, for the first minute or so, voltmeter reads about 9 to 10 volts and won't increase unless I raise the rpms to around 1100. After a minute like that it goes to low 13 volts. 1st fan on and around 12.2 and 2nd under 12 volts. Also, something seems wrong with the voltage fluctuating and the second fan sounds sick somewhat like low voltage until I throttle up. After nursing it up to temperature it's pretty much the same, however, the new voltage regulator was very Hot! I never touched the old reg so maybe it was the same. The old one was a Mopar unit and on the back the partially transparent goop had some very small bubbling in one spot. After this Napa job I inspected the back and nothing wrong. I have good grounds at the Regulator and fire wall which I re-sanded and greased the contact areas. Question: The section of the alternator that resides between the 2 covers has a a winding look to it and is different thicknesses from alt to alt, I believe depending on the output capability. I noted a small scraped section that goes across several of the grooves. Could any damage there cause a problem with the alternator?? By the way, when I step on the throttle to around 1400 rpms the charge rate goes to almost 15 volts! At this point I am ready to punt and just get an newer style ,internally regulated alternator and be done with it; I hope. Any suggestions besides loading up the 12 gauge and putting the barrel in my mouth?!?

 

[JDmac72chrgr]

You replace that 9 year old battery?

 

[multimopes]

I hain't done that yet but was thinkin about it for a while. I have a Optima Red Top and it's been great but as mentioned just about 9 years old. I am scared shitless about which brand to try now as I recently read that there are now only 3 major battery makers out there and the price is through the roof! My son and I just had to replace the battery in his 93 Jeep Wrangler and the about cheapest was $125.00 and it's pretty much a piece of crap. I also know that Optima sold out and their batteries are now unreliable crap like many others. Years ago a friend had a Willard Industrial Battery that was a great, long lasting piece. I doubt they are even in business any more. Any suggestions are appreciated. I did have a sealed Delco in my old Ramcharger that was in it when I bought the truck from the used car lot. I got 16 years out of that one but I don't think anyone makes a decent American built unit anymore.

 

[JDmac72chrgr]

Went Diehard on my 72: Johnson controls makes a great portion of batteries any more: did NOT go gel, dad had gels in his 92 motorhome, they literally exploded, went back to old acid type, rather add demineralized water then blow up battery: 9 & 16 years?? THAT is unheard of, 4-6 at most, even if car sits, got your money's worth for sure. Forgot your RR was street/strip car, different electrical setup: Change battery, throw a 2 amp charge on it for 48 hrs, check battery voltage, 13.1 + volts, install and then see what you have: SUPER CLEAN/SHINY connections, any "green" on battery wires, not good: maybe check ohms before hooking battery up to ensure good continuity between battery wire & alternator and starter (high ohms =voltage loss) check ohms across trunk shutoff too.

 

[multimopes]

Thank you sir, I am going to get me a new battery as it has given good service. By the way, that Delco was almost 2 years old when I got the truck, so really almost 18 years. A testament to a damn good battery and an excellent charging system. I know it was Johnson Controls who bought and scuttled Optima. I like the sealed batteries and was hoping to find one that was a high output deep cycle. The battery was only showing about 12.16 volts when I checked it with car off and about the same after charging for a spell. Also, I only later knew that an Optima battery is supposed to use a special kind of charger, which I never had. I want to see what Tuff Stuff has to say about what I found so far. Regardless of the battery, I need & want something in the way of an alternator that is turn key reliable in regards to output at idle.

 

[JDmac72chrgr]

Roger on that multi!! Bad battery will draw voltage down for sure: 12.16 v not good as should be. Big believer in good grounds too. Learned that from several Chevys with tow behinds. Good luck with it multi!! Time for LO/TO of HRSG & gas turbine & boiler & chillers readings. Keep us updated.

 

[383man]

You really cant check the charging system right with just a voltmeter. If your battery is a problem if you had an ammeter hooked in series to the output wire it would tell you what the battery is taking in. I have had a few over my 40 years as a tech where the battery was taking in 35 or more amps on 40 to 60 amp alt and still not going over 13 volts even if I charged the battery. Put a new battery in and then the amps dropped to about 8 to 10 with everything off and battery volts was at 14.5. Good luck with it. Ron

 

[multimopes]

I agree thank you, I finally found my amp probe as well. On my second retest with the new voltage regulator, at idle with no fans or anything else on the voltage was around 9 or 10 which is piss poor until I ran it for a minute or two. It also doesn't crank as fast as it used to. I think the battery is on it's last legs. I will try a few more tests but meanwhile look for a new battery. By the way I added 4 extra grounds way back when all over the car. Also, I want a sealed lead acid type similar to the Optima. I don't want fumes in the car as it's mounted in the trunk in a plastic battery box. Some one on here said some of these alternators don't charge right away unless something "excites" it. Maybe that was the internally regulated type. Any thoughts on the voltage regulator getting hot like that??