1968 Olds Cutlass 442

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We have a 1968 olds cutlass 442, 400 engine. This thing for the last 18 months or so, has not held/sent a proper charge to the battery. :cussing: We have replaced the alternator, voltage regulator, and the battery, and battery cables. Within 3 days of a full charge to the battery, it's dead again. :banghead: Any ideas on this?

posted by  Diblue1121

It could be both the battery and the alt. The battery should be fully charged prior to starting with a new alt because the alt will slam into a full charge mode and usualy burn out a diode. And if the alt is bad with a new battery then the battery doesn't get recharged properly. It could also be a short somewhere.

posted by  srober32

look for a draw on the battery, something is killing it overnight :thumbs: if your info is correct and all new parts, good connections and all

posted by  BanffAutoSpa_ap

how about this...

charge the battery fully and use a voltmeter to find the voltage in the battery (12.56 or so). then start the car up and see how much your alternator puts out (14? 15?). then go for a stroll and come back and disconnect the battery. see how many volts are in it. record that number. leave the battery disconnected all night and check the voltage again the next morning. if the number is more or less the same, do the same thing the next night but leave the battery connected. if the voltage drops now, you ahve a drain somewhere. if it is still the same get your charging system tested. i don't care what parts stores tell you have the battery test them after it has been discharged (don't test a fully charged battery).

pretty self explanatory, try to distinguish between a parasitic drain or a charging system problem.

posted by  carls47807

Yeah, if you have the time! lol

posted by  srober32

if he doens't have the time, he shouldn't be wasting mine :)

posted by  carls47807

if you've got the time... i've got the place... wasn't that a beer commercial?



if batt. voltage is 12.55, should it be charged? :laughing:

posted by  dodger65

O.K. Have had the alternator tested this afternoon (off the car) and it tested fine. Before hooking up the new alternator (actually...swapped out the alternator for a new one, and had them test it before it left the store) did this while charging the battery at home...Battery was fully charged, and we hooked back up the alternator. The alternator was run through a box (looks like a relay) on the inside driver side fender, and we rerouted it directly to the battery, after we replaced the output wire. We have also just recently (few days ago) replaced the voltage regulator. It isn't a problem of the battery draining overnight or anything...it's while running. Our friend who is currently driving this car, said that today, on his way home, it seemed to be doing much better. Since we replaced the voltage regulator, the generator light in the dash has stayed on...as he excelerated, the light would go off, as he slowed down, it would come back on. We are taking the battery in to have it tested tomorow...provided it has run down some allready. Beyond it being the battery now...we are at a complete loss, and have methodically worked our way to this point, for a little success so it seems.

Hubby just informed me that there is a short in a tail light socket...and he and his father think that could be part of the problem...however...the headlights work weather the car is running or not...the car only seems to discharge when it's being run (no headlights on) if it was the tail light, would it not discharge overnight?

P.S. I'm a she, not a he :wink2:

posted by  Diblue1121

Since the test is free, take the whole car in and have it tested, the whole charging sytem and the starting system, it could be a bad regulator, even though it is new. They should be able to pinpoint it much easier than we can on the 'net, she not a he. :mrgreen:

posted by  srober32

I think the only part of that, we have not done yet, is testing the starter, which we have contimplated doing today, weather providing...This is an odd problem to me..and was just curious if anyone else might have some ideas that we haven't thought about yet :mrgreen:

posted by  Diblue1121

if this helps great

posted by  osborste

Very Cool! :thumbs: We've been trying to hunt down some wiring diagrams with very little luck. Thank you!

posted by  Diblue1121

check for shorts int he electrical system.

posted by  tbaxleyjr

where are you guys getting these diagrams? do you have one that includes the ignition switch?

posted by  dodger65

www.autozone.com repair info, repair guides,select yr no listing for olds chose chevy malibu repair info comes up 64-88 mid size ,chassis electrical,wiring diagrams

posted by  osborste

http://www.442.com/tech/tech.html found this one yesterday, and it has been a lifesaver. I think we have tracked it down to the wiring harness off the alternator, or the alternator is not putting out enough to charge the battery. Now, affording/finding a new one.... :banghead: haha.

posted by  Diblue1121

glad you found it

posted by  the lobster

All our wiring is hooked up properly, and I think we have finally diagnosed it as...NEVERY BUY A CHEAP ALTERNATOR!!! :laughing: The alternator on this car isn't exactly cheap, and my husband should have just held out and rebuilt the one we had (he says he couldn't find the diodes for it at that time.) The alternator on the car isn't putting out over 12.4 volts, and that's not enough to keep the car properly charged...we are going to be taking it in today, and having the alternator, and voltage regulator retested...and I'm not leaving the store till they get me an alternator that tests 14+ in the store, or give me my money back, so I can go get a decent one for this car. I talked with some guys from OReilly's who showed me what their alternator's are testing off the car, and all 3 they tested there for me were testing off the car 15+, our is only supposed to test 13...so, once again, Advance Auto Parts, (who I very rarely have probs with) has given us a bad alternator (or at least the wrong one for this car.) The voltage regulator that Auto Zone sold my friend, is just like the one we pulled off the car, but about 1" shorter in height from all the others we've found for the car.

posted by  Diblue1121

Haha, all that, and it's still not working right :banghead: :cussing: :banghead:

posted by  Diblue1121

OK, lets go trough this one more time. Disconnect the battery, clean it so there is no dirt, acid, corrosion or gunk on it or the terminals. Check that the cels have the proper amount of electrolyte in them, they should be right at the bottom of the tubes under the caps. If they are low fill them with distilled water to the proper level. Put the battery on a trickle charge(2 to 10 amps) for 8 to 24 hours. Check the connections to the starter, the engine to battery ground, the engine to frame ground and the condition of the cables themselves, if you see any bumpy or kinked or split sections replace the cable. If you see that the cable cannot be tightened sufficiently, replace the cable. Take the alt and voltage regulator off again and take them to be tested. Make sure that they check the condition of the diodes in the alt. When you re-install the voltage regulator, make sure that it has a good ground. Pull battery off of charge at the proper interval and check the voltage should be around 13.5 volts or so. re-connect the battery positive cable first. When you attatch the negative cable, make sure all accessories are off(best bet is to pull all of the fuses),look for a small spark(usually works best in a dimly lit garage) if there is one you definately have a drain. With you rhandy dandy hydrometer, test the specific gravity in each cell of your battery. The readings should all be the same, about 12.65 (if I recall correctly). If you have one cell substantially lower than the others then you have a bad cell in that battery. If not then we will do a drain test. Disconnect your coil wire and crank your engine for 5 to 10 seconds. Repeat two more times. Wait about 15 to 20 seconds and check your battery voltage again. It should be at 12.2 to 12.6 volts, if not you have a bad battery. If all of these check out then you have to start looking for a short somewhere in the system and with the fuses out it is a good place to start. You see, if the battery is not fully charged when you start the car up, the regulator goes into full-field and usually pops a diode or two, which could be what is happening here. Sorry to be so long winded but to accurately pin the problem down these are the steps that should be taken and the battery definately has to have a full (not just a surface) charge on it to begin with.

posted by  srober32

BTW, let's see some pics of the car! I love the 442's.

posted by  srober32

i had the same problem with my 71 350 external regulated alternator. you need to bypass the regulator to a new internally regulated alternator.
i attached a pic of the bypass needed.
it works great and i havent had a problem since.

posted by  neslorelyks

in the 60 s they were using germanium diodes with a .2 volt drop.the newer regulators have silicon diodes which have .7 volt drop. this could be causing a problem.maybe the pulley on the alternator is not the right diameter.i would do what you did.
use a late model internally regulated alternator.but if there is a drain when operating ,to the point where it cannot charge the battery,something is pulling current over 20 amps.if the generator light is on,there is not enough alternator output except at higher rpm....a sign of a shorted diode,one or 2 charge cycles are not there.the diode block is a bridge rectifier, and it can be tested with an ohmmeter.each diode should have infinite resistance one way,(over 500kohms) and on diode check a .7 volt drop ,or 20 ohms or so in the other direction.if diodes go they usually short.if the regulator rectifier is one unit it is more difficult to check,you need a variable power supply,set it to 15 v and test the output as the voltage is varied from 12 to 15 volts.

posted by  the lobster

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