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| ziggy |
 Nov 14 2011, 08:39 PM
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#1
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Newbie  Group: Members Posts: 19 Joined: 2-May 11 From: Austin, TX Member No.: 13,013 Region Association: Southwest Region  |
Howdy, first time caller, long time listener. I've got a '73 in yellow in the Austin, Texas area. PO did some mod stuff like the 911 master cyl and lowering the car. It has the requisite amount of rust and will be getting a whole lot of new metal when I pick up a mig machine. Also, I am probably insane - it is my daily driver ( I do have occasional access to a bug I work on) and after six months of working on it in a dirt driveway I finally have an old shed for a garage. The only real mod I have done is replacing the ignition switch. Those connections were all kinds of wonky when I pulled the old one so I put in a panel that separates the circuits with toggle switches and soldered the whole thing point-to-point. Master switch on left creates a hot bus, also mimics factory "off" or actual off, then radio, accessory, engine systems and then starter. Key is still needed to unlock steering wheel.
Now I have come across something strange. Alt light is on and gets very bright when I use blinkers or brake light. Headlights don't help, either. Idle is hunting like crazy and gauges seem a little erratic. Did the alternator diode test as per PP's article and neither B+ nor D+ tests killed the light, although they dropped the idle until the engine died. Problem started when I lost the alt belt and I replaced the belt and volt regulator at same time and was surprised to get no change. I want to get as much insight as possible before I tear that thing out. Any ideas? Attached thumbnail(s)  
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| ziggy |
Nov 16 2011, 12:54 AM
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#2
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Newbie Group: Members Posts: 19 Joined: 2-May 11 From: Austin, TX Member No.: 13,013 Region Association: Southwest Region |
Re-performed diode test and also tested battery and short to ground:
Both (D+ to DF) and (DF to Batt+) made light brighter and idle drop. (D+ to DF short) to ground voltage: 19v Battery post to post voltage while running: 13.5v Same while not running: 13v Muffler bearing? Glasspack duallies? (IMG:style_emoticons/default/confused24.gif) |
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| Spoke |
Nov 16 2011, 01:32 AM
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#3
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Jerry Group: Members Posts: 7,158 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None 
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QUOTE(ziggy @ Nov 16 2011, 01:54 AM)  Re-performed diode test and also tested battery and short to ground: Both (D+ to DF) and (DF to Batt+) made light brighter and idle drop. (D+ to DF short) to ground voltage: 19v Battery post to post voltage while running: 13.5v Same while not running: 13v Muffler bearing? Glasspack duallies? (IMG:style_emoticons/default/confused24.gif) Connecting D+ to DF and DF to Batt+ making the idle drop is somewhat normal as the alternator is producing maximum energy and is loading down the engine. Assuming you measured D+ to DF at 19V at the same time you measured 13.5V on the battery seems to point to an alternator issue. Maybe the diodes on B+. The same alternator windings producing the D+ to DF voltage at 19V are producing the battery voltage too. The battery too should be 19V in this case. Being the battery will be a big load, the battery should hold the voltage to about 14, maybe 15V. This will hold D+ to DF also to about 14-15V. I think you have something wrong with the diodes in the battery charging portion of the alternator. |
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| rwilner |
Nov 16 2011, 06:35 AM
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#4
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No Ghosts in the Machine Group: Members Posts: 953 Joined: 30-March 10 From: Boston, MA Member No.: 11,530 Region Association: North East States |
I'm not much help with your troubleshooting, but I am really digging your ignition switch mod
(IMG:style_emoticons/default/biggrin.gif) |
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Posts in this topic
ziggy Introduction and questions Nov 14 2011, 08:39 PM
ziggy This one didn't come through the first time: Nov 14 2011, 08:44 PM clow :wttc:
Electrical is not my thing but you said ... Nov 14 2011, 09:19 PM ziggy I replaced the regulator as I had been driving wit... Nov 14 2011, 09:58 PM clow I am not fully sure about the regulator. Would it ... Nov 14 2011, 10:19 PM jcd914 My 5 second description of regulator function:
Vol... Nov 14 2011, 10:58 PM ConeDodger :wttc: Now buy some jackstands, and cuddle up to p... Nov 14 2011, 11:19 PM rick 918-S :wttc: If I were you I would get a dash and igniti... Nov 14 2011, 11:28 PM ziggy I like my version better than the factory's (n... Nov 15 2011, 12:17 AM
Spoke
I have a feeling it is not the regulator since th... Nov 15 2011, 04:25 PM Dave_Darling Check your fuses.... A blown one or a bad (dirty)... Nov 15 2011, 01:29 AM zymurgist :wttc: Nov 15 2011, 08:28 AM nsr-jamie Yes, check fuses first. I can see them in the pict... Nov 15 2011, 08:45 AM m170seeker Ziggy, I am in Austin too. Nov 15 2011, 11:29 AM ziggy The fuses all check out. I'll be updating them... Nov 15 2011, 04:09 PM Drums66 WELCOME :flag1: Nov 15 2011, 05:19 PM ziggy Well, I put in a new alt and viola, problem solved... Nov 20 2011, 04:30 PM |
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