Charging Problems
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
Charging Problems
Just replaced the alternator and the battery in my '88 and its still only reading 11.8 from the dash voltmeter.
What should I check next? What readings should I be getting at the battery and alternator?
What should I check next? What readings should I be getting at the battery and alternator?
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
We just went through this with another member. Check the red wire on the back of the alt and see what condition it's connector is in.
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
I believe they are 12ga stranded. If your power wire is too short, I would recommend soldering that splice and shrink-tube on the connection with the proper size eyelet. No loose splicing or crimp-on terminals here, solder everything.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
I'm thinkin that continuity would be compromised if solder were to take the place of wire, not if it were used to keep connections together.
Instructor
Joined: Jun 2003
Posts: 193
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From: Central Ill
: qOTE=caddyboy84;1580735558]I'm thinkin that continuity would be compromised if solder were to take the place of wire, not if it were used to keep connections together.[/QUOTE]
Just went thru this on my 89 coupe and after three alternators i was ready to pull my hair out as i am not good at elctrical problems got good info from another member to check voltage at the alt on mine i have two big red wires one in the clip in pigtail and another singe wire the shroul on the terminal was covering the connection between the terminal and the wire once i got the covering that connection was corroide respliced and it works fine. On the single re wire just hook aup a seperate volt meter to that stud and you shoul;d have the same voltage as you have at the battery same for the clip on connection. Hope this helps.
Just went thru this on my 89 coupe and after three alternators i was ready to pull my hair out as i am not good at elctrical problems got good info from another member to check voltage at the alt on mine i have two big red wires one in the clip in pigtail and another singe wire the shroul on the terminal was covering the connection between the terminal and the wire once i got the covering that connection was corroide respliced and it works fine. On the single re wire just hook aup a seperate volt meter to that stud and you shoul;d have the same voltage as you have at the battery same for the clip on connection. Hope this helps.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
You mean when Im testing with the mutimeter I should touch the alt's pigtail wires and also test the wire that connects to the back with the nut? THe wire on the back is a power wire-last time I touched it it sparked? Did I do something wrong or? Also with the engine running-the alt and the battery should both be the same voltage in the 13-14 v range?
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Burning Brakes
Joined: Mar 2012
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From: California
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You mean when Im testing with the mutimeter I should touch the alt's pigtail wires and also test the wire that connects to the back with the nut? THe wire on the back is a power wire-last time I touched it it sparked? Did I do something wrong or? Also with the engine running-the alt and the battery should both be the same voltage in the 13-14 v range?
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
any chance you could post a pic? get a set of jumper cables and connect to the negative post on you battery and the other end on an engine ground, I use the alternator bracket. Theres a small ground from the negative post on your battery to the frame, and sometimes, depending on po's there's a small ground from the back of the block to the firewall. your multimeter, set on 20volts, the black lead to ground, the red to the main charge post on the back of the alternator. you get good volts there, and its a wire chase after that.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
Its 10pm so Ill have to wait til tomorrow to take pics. With the ignition off Im getting 12.33 at the battery and at the nut on the alternator. With the key in the ON position both drop to 12.25. Before I did this I disconnected the battery so I could mess with the alt wiring and after I hooked it up and started the car it didnt wanna idle. The battery connections are tight and so is the belt. I started it a few mins later and it idled but kept moving from 1400 down to 8-900 and even down to 700 rpm-then came a hissing noise(sounded like it was coming from the drivers side header or intake plenum so I shut it off. The car will stay running if I tap the gas though. I just drove the car this morning and besides the alternator problem it ran fine-not sure what has changed. Also despite what the multimeter read my dash voltmeter was only at 11.6 or so volts.
Last edited by armybyrd; May 6, 2012 at 05:27 PM.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
it sounds as though you may have a wire in the wrong place and is grounding out. the advantage of the pic , is that some of these folks can see what you've actually done and possibly look at it and know right off what needs to be done.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
Little update: I was checking for vacuum leaks since its stalling and I found one near the distributor-looks like 3 lines go into the plastic peice-only ones connected though it goes down by the distributor and I couldnt see where exactly it goes to, the other has the rubber hose but I couldnt see where it wouldve connected.
http://www.flickr.com/photos/77943619@N03/
http://www.flickr.com/photos/77943619@N03/
Last edited by armybyrd; May 7, 2012 at 02:30 AM.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
in your alternator, those butt connectors are junk, have you instructor give a class on soldering, in the pic 65 with your hand on that hose, if it runs to that round can, is part of your vapor recovery. 66 appears to be part of your cruise control, if its not working plug it. why is there a black wire on the charging post of your alternator, that big red wire with the nasty lookin butt connector hanging loose probably should go there, that is not a ground, the black wire needs to go almost opposite that at the boss with a threaded hole
dude, seriously, buy an fsm
dude, seriously, buy an fsm
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
the black wire is connecting the big pink wire to the back of the alternator-it was a quick fix since I didnt have any thicker wire on hand. I figured soldering would be better than those junk butt connectors and but my instructor said otherwise though obviously I need a better instructor. Ive got an FSM-it doesnt answer everything and in between posting questions here I do searches and look in my manual to try and get answers myself. Will the vapor line effect idle at all?-I didnt see a spot for it to connect to.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
in your alternator, those butt connectors are junk, have you instructor give a class on soldering, in the pic 65 with your hand on that hose, if it runs to that round can, is part of your vapor recovery. 66 appears to be part of your cruise control, if its not working plug it. why is there a black wire on the charging post of your alternator, that big red wire with the nasty lookin butt connector hanging loose probably should go there, that is not a ground, the black wire needs to go almost opposite that at the boss with a threaded hole
dude, seriously, buy an fsm
dude, seriously, buy an fsm
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
That hose is vapor return to your tank, the can is the filter for that. the black to the threaded boss is a ground, if you have the fsm, it should have a wire diagram for the entire car, also an emissions hose routing diagram. If you dont have those , the venders have them in their tech. wilcox and zip come to mind. you dont need a better instructor, you need to open your mind and dont look just in one place for the answers. take those same quality pic's of all of your engine, both sides, lets see what else your missing.
Last edited by oldalaskaman; May 7, 2012 at 07:55 AM.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
where exactlys the threaded boss your talking about? I dont have the car or fsm in front of me. The reason I made that comment about the instructor is since he said not to solder the alt connections and has made other untrue statements about diagnosing the charging issues.