88mj34tsl Posted July 25, 2012 Share Posted July 25, 2012 I have a 88 comanche. Ive tried everything i can think of and can't get my alternator to charge. I have been told you can convert a stock alternator to a one wire. Wondering if this is true. Or how much trouble it would be to run a gm one wire Link to comment Share on other sites More sharing options...
Blue88Comanche Posted July 25, 2012 Share Posted July 25, 2012 :popcorn: Link to comment Share on other sites More sharing options...
Pete M Posted July 25, 2012 Share Posted July 25, 2012 have you taken it to an auto parts place to have it tested? Link to comment Share on other sites More sharing options...
cruiser54 Posted July 25, 2012 Share Posted July 25, 2012 Have you checked for battery voltage at the threaded stud on the alternator and for 12 volts at the yellow wire in the two-wire plug at the alternator with the key on? Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 I put a new alt. On it. I had the old one tested 5 or 6 times it tested out great. So i put it back on. Ive checked the fused link. I have 12 volts at the stud and the yellow wire on the plug. Link to comment Share on other sites More sharing options...
mvusse Posted July 26, 2012 Share Posted July 26, 2012 Maybe the problem is that your battery can't hold a charge anymore. I would take the battery in to have it tested. Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 I just replaced the batt for that reason. I had it tested before i brought it home. Does the computer control the charging system. Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 Is it true that a stock alt can be converted to a one wire Link to comment Share on other sites More sharing options...
cruiser54 Posted July 26, 2012 Share Posted July 26, 2012 I just replaced the batt for that reason. I had it tested before i brought it home. Does the computer control the charging system. No. If the alternator is good, it should be charging if you have voltage at the stud all the time and 12 volts at the yellow wire with the key on. Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 The same battery charges in my beater truck. And i have had multiple good batterys in it. For example the battery out of my daily driver Link to comment Share on other sites More sharing options...
mvusse Posted July 26, 2012 Share Posted July 26, 2012 With the engine running you should have about 14 volts at the stud. If it reads 12V with the engine running you're reading the charge from the battery. Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 Its reading 12v and drains down the more load you put on it. Ive been tryin to figure this out for over a year. Three different alt probably a dozen batteries. Can you convert it to a one wire system Link to comment Share on other sites More sharing options...
Pete M Posted July 26, 2012 Share Posted July 26, 2012 corrosion in the wires? Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 26, 2012 Author Share Posted July 26, 2012 It very easily could be. The truck sat for many many years in a wood line. Took me a long time to get it running and driving. This charging problem is the only thing i can't figure out Link to comment Share on other sites More sharing options...
Eagle Posted July 27, 2012 Share Posted July 27, 2012 I just replaced the batt for that reason. I had it tested before i brought it home. Does the computer control the charging system. No. On the GM alternators, the voltage regulator is built into the alternator. The ECU has nothing to do with it. If the battery tests good and the alternator tests good, there's obviously a wiring problem in the vehicle. Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 27, 2012 Author Share Posted July 27, 2012 What wire do i need to double check. Can i just run new wires. What does the other wire on the plug do (brown with black stripe) Link to comment Share on other sites More sharing options...
cruiser54 Posted July 28, 2012 Share Posted July 28, 2012 I just replaced the batt for that reason. I had it tested before i brought it home. Does the computer control the charging system. No. On the GM alternators, the voltage regulator is built into the alternator. The ECU has nothing to do with it. If the battery tests good and the alternator tests good, there's obviously a wiring problem in the vehicle. And according to the OP, the wiring is good........... Link to comment Share on other sites More sharing options...
Eagle Posted July 28, 2012 Share Posted July 28, 2012 And according to the OP, the wiring is good........... No, he said he checked the fused [sic] link. That's only one of the wires in the charging circuit. The direct answer to the original question, though, is that the alternator can be replaced with a delco one-wire. But, with an undiagnosed problem lurking somewhere, I'm not convinced that doing so is a good idea. On the other hand, it could be brilliant. :???: Link to comment Share on other sites More sharing options...
88mj34tsl Posted July 28, 2012 Author Share Posted July 28, 2012 So if the yellow wire on the plug has a steady 12v and a good connection is made. Between the stud and the batt+ it should charge. Correct? Link to comment Share on other sites More sharing options...
cruiser54 Posted July 28, 2012 Share Posted July 28, 2012 Key off, got voltage at the stud? Key on, got voltage at the yellow wire? If yes and yes, it should charge if the alternator is good. Link to comment Share on other sites More sharing options...
Eagle Posted July 28, 2012 Share Posted July 28, 2012 FWIW, I've had two NEW (not rebuilt) alternators from Auto Zone (their Durolast Gold line) that were DOA out of the box. And people to whom I have mentioned that typically respond with, 'Yeah ... that's normal." Link to comment Share on other sites More sharing options...
mountainman Posted July 28, 2012 Share Posted July 28, 2012 yeah rule of thumb is...never buy any electrical stuff from autozone. EVER. Napa or Oreilly. I order from rock auto and be happy. :) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now