heneghan@ihu1m.UUCP (Joe Heneghan) (09/23/85)
I have a 72' Dodge, and occasionally while night driving, the dash lights get very bright and the alternator meter almost pegs itself to +40. I don't know what the scale is, but it ranges from -40 to the left, a middle position, and then +40 to the right. Normally the needle is in the middle position. Does this indicate a faulty alternator, a faulty voltage regulator, or what? It only happens during the night with the lights on. Thanx in advance Joe Heneghan
tmorris@convex.UUCP (09/24/85)
It looks to me like you are applying full current to the
field windings of the alternator. The easiest place for that to happen
would be the voltage regulator. Take a look at the wiring harness first,
just in case there is a visable short between the green(or blue on some)
wire and any other wire or terminal.Also make sure the voltage regulator is
securely mounted and grounded .
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moroney@jon.DEC (Mike Moroney) (09/26/85)
>I have a 72' Dodge, and occasionally while night driving, the >dash lights get very bright and the alternator meter almost >pegs itself to +40. I don't know what the scale is, but it ranges from >-40 to the left, a middle position, and then +40 to the right. Normally >the needle is in the middle position. Does this indicate a faulty >alternator, a faulty voltage regulator, or what? It only happens during >the night with the lights on. Sounds like a bad voltage regulator to me. Probably one of the internal relays is sticking, telling the alternator to keep charging the system (showing the +40 on the ammeter) which also will increase the system voltage which shows up as brighter lights. I bet your car devours headlights and other lights, too. It's probably best to get it fixed soon, excessive voltage may cause your battery to explode. -Mike Moroney ..decwrl!rhea!jon!moroney
dave@cylixd.UUCP (Dave Kirby) (09/26/85)
In article <687@ihu1m.UUCP> heneghan@ihu1m.UUCP (Joe Heneghan) writes: >I have a 72' Dodge, and occasionally while night driving, the >dash lights get very bright and the alternator meter almost >pegs itself to +40.... Forgive me for posting instead of mailing. Your mailing address is too long for my system to handle. Sounds like the voltage regulator to me. The mechanical VR in your Dodge is essentially an on-off switch that supplies 12V to the alternator windings when the voltage output is too low, and cuts the juice off when the output is too high. Sounds like the relay sticks to the high side when you suddenly pour on an extra load, like when you turn on the lights. Get that thing fixed before it burns up your electrical system. An unregulated alternator can put out several times its nominal voltage when you are going at high RPM. ----------------------------------------------------------------- Dave Kirby ( ...!ihnp4!akgub!cylixd!dave) (The views expressed herein do not necessarily reflect those of RCA Cylix. They may not even reflect my own.)
king@kestrel.ARPA (09/29/85)
In article <687@ihu1m.UUCP>, heneghan@ihu1m.UUCP (Joe Heneghan) writes: > I have a 72' Dodge, and occasionally while night driving, the > dash lights get very bright and the alternator meter almost > pegs itself to +40. I don't know what the scale is, but it ranges from > -40 to the left, a middle position, and then +40 to the right. Normally > the needle is in the middle position. Does this indicate a faulty > alternator, a faulty voltage regulator, or what? Almost certainly a faulty voltage regulator, whose mechanical relay is sticking in the "full charge" position It only happens during > the night with the lights on. > Thanx in advance Joe Heneghan My guess us that the relay never REACHES full charge in the daytime because you have insufficient load to cause you to invoke full charge. WHEN THE PROBLEM IS OCCURRING YOUR BATTERY IS MANUFACTURING HYDROGEN. THIS IS TRUE EVEN IF MY DIAGNOSIS IS WRONG. THIS IS DANGEROUS. FIX IT N-O-W! Sorry about my delay in responding. -dick
christensen@apollo.uucp (Wendy Christensen) (10/11/85)
(Yes, I am showing my woeful ignorance here.) Recently, I had the alternator in my '66 Chevy replaced. (It started to screech and howl rather suddenly.) Could a faulty or failing alternator have been the cause of otherwise unexplained intermittent failings of the horn and the power windows? Also, is "compression of 150 psi all around" considered good? If so, why? Thanks, in advance, for any enlightenment. (And please reply by mail!) w. christensen ...decvax!wanginst!apollo!christensen