Check Engine Light came on yesterday . Every thing is working ok except voltage is up around 16 or 17 . Since the voltage is high figure the alternator is ok and it must be the regulator . So today I put on an external reg. as per Haulin-in Dixie . Still put out high volts . If I switch the wires on the reg. it puts out nothing . According to Haulin's post it's not supose to matter which terminal goes to which , only matters where the 12v ign. goes to on the alt.. I'm back to square one , help....... thanks

PS All the searches indicated no output mine is too high

 

The regulator should take care of that....have you put a Fluke (generically used name for a multimeter, where I come from) on it and tested to see if it's a mis-calibrated output reading from your gauge? Did something change, and suddenly you are getting the high V readings?

 

Yes I did put multimeter on it and it reads the same as the gauge . Nothing changed that I am aware of , out of the blue CHECK ENGINE light came on because of high volts. With no wires connected I get continuity between the two small turminals on the alternator , also with the two terminals on the regulator , is this correct?

 

Where did you connect the Fluke - upstream of the regulator or on the "battery side"? Silly question, but...just checking!

The regulator should shut charging off (regulate) if the voltage gets TOO high (or you'll cook your batteries)....the alternator should be putting out up to 14.5-ish volts when running, current output should depend on the load (and should be tested as such). I'm tring to figure out how a diode bank issue might be putting out more than the 14.5V....?

No new components added anywhere in the electrical system, no recent need to charge the batteries? This is a good one - let me pore over some schematics to see if I can find a bug.

Anybody else, please chime in - I HATE e-problems, and am not that good with them!
Rauschbo

 

OK a litlle more info . Just did another check , I have ground continuity between each of the small terminals on the alternator and the case . Is this ok and if not could the alt. be grounded internally rendering any regulator useless?

 

Load test both batteries , one bad one can give you this problum, if one tests bad then replace both , a battery bank is like a chain , its only as stonge as the weakest link and if you have a weak link you'll have more problums.

 

Disconnected both batteries and load tested , both tested good . Was wrong about the ground continuity of the alt. terminals , that was with the wires connected to the external regulator . With wires off there is no ground continuity , that seems to blow my theory of it being internally grounded . Truck started several times with only one battery , and they tested good , so for now I've ruled them out .

One thing I'm still not sure about is I took the 12v power supply for the remote regulater from the blue wire that originally went to the alt.. It only has power with ign. so I thought it would be OK , but who knows , it's truck wiring.

Other thought , how can I check the new regulator , maybe it was never any good , I have that kind of history.

Thanks again to all

 

I think you're on the right track, it has to be the regulator. Now about testing it....I wonder if the overcharge condition already indicates a failed test?!? I think that if you didn't have 12V to it, it would either not regulate at all (overcharge) or not pass any current (undercharge) - depends on the "default" status of the device. Why did you install this new regulator, was the system overcharging before? It sounds like you either purchased a bad new regulator, or it is not getting the req'd supply voltage.... you might test the power wire while wiggling it, it may have an intermittent open.
If the config is similar to a Nippondenso, you could have a bad negative rectifier circuit, or a non-grounded one; Looking at this would require tearing the unit apart - probably not the HIGHEST thing on your priority list!

If you can get to a Schucks / Autozone or similar parts store (after calling first to make sure they can test the regulator!), it might be worth the trip - although in the current confguration, you certainly appear to be overcharging your batts!

 

Yes system was overcharging before , that's what started this whole thing in the first place . Hooked up ext. reg. again as per diagram except took 12v power to the top terminal on alt. direct from bat. , so I'm sure there is power to it . Here are the symtoms ;
1 wired as per diagram = 17v
2 wired with terminals switched on reg. =12v (no charge)
3 wired with no 12v supply = 17v

According to Haulin's original post it's not suppose to matter which terminals on reg. are attached to the terminals on the alt. , only that the 12v supply be attached to the upper terminal on the alt.

I'm off to find another reg. to see if that is the problem

 

If all your testing is correct , then its time to look at the alt. it sounds like its lost the connection to batt. internaly , if alt lose there sensor to batt. then they run wide open.

 

OK some good news . Put on another reg. from NAPA(VR38SB) $15 made inChina . Wired it up , fired it up and14v , put the lights on , put the fan on , 14v . Looks like the first one was N/G right from the get go ( BW R296 , $38 made in USA)

Thanks to everyone for the suggestions and help , I'll get back to you if it doesn't hold up.

BTW , took the 12v power supply from the original feed for the alt. , the blue wire , it's only on with ign.