Electrical Problems

[RamAZ]

I have a 92 and the charging system has gone crazy. Yesterday when leaving work the voltage meter went to 12 volts and the fuel, temperature and oil pressure were reading high.



Use the turn signals and the volt meter goes to 8 and the temperature cycles in time with the turn signal. The fuel and oil pressure gauges just peg out.



With the motor running and in my drive way I turned on the lights and the voltage went to 8 and the other three meters went to max (high).



I let it set for 30 minutes and started the motor again and the same sequence of events happened. I cleaned all the connections at the battery and alternater about two weeks ago prior to going on vacation and recleaned the battery terminals yesterday also. Battery is 2-3 years old and the negitive cable is new. I checked the battery with a hydrometer and all cells read good.



Started it up again and all was well. This afternoon was on my way across town and the volt meter went to 12 volts and the meters went high. The best thing was when I turned on the lights to see if they affected the gauges as before the speedometer went to zero and stayed there till I turned off the lights.



When charging now the alternator is erratic. Close to 14 volts sometimes and half way between 12 and 14 sometimes. The voltage will go down when ideling and go higher when the RPM's are up.



So has this kind of thing happened to anyone else with a first

generation. Any ideas: battery, alternator, fuseable link with high resistance,engine controller or shorted wire.



Thanks in advance. I'm lost.



Jim

 

[Philip]

You say the neg cable is new. Did you hook up the small wire from it to a body ground? (It would have been grounded on the raditor support for your year model)





What you are talking about sounds like the lose of a ground from the body to the battery. Electric will go to ground threw the eastest path. If that means going threw another circuit. It will. So you need to check body grounds. The engine is mounted in rubber. So do not count on a engine ground to be enough. For a quick test. Hook a jumper cable from the battery minus terminal to the frame/body. See if you electrical grimlins go away. If they do. Then that tells you to improve you grounding.

 

[RamAZ]

Update on electrical problems.

I may have found the item that was causing my electrical problems, There was paint under the wire coming off the negative battery cable to body. I cleaned the area and reinstalled wire.



I also ran another ground wire off the post to another part of the body. I then verified continuity of all grounds back to negative post. I then verified that there was continuity between all points not using the negative post,



The voltage of the battery was 12. 4 volts and when charging the voltage rate was 13. 9 volts.



I hope this has cured the problems for now. Thanks for the fast replys. I never thought to look under the wire to body connection. It's clean now plus an additional ground run.



Thanks again.



Jim

 

[Philip]

Your battery voltage looks good at 12. 4 not running. But you charge rate of 13. 9 is a little low. It should be up around 14. 5. But it is acceptable at that voltage. I would not go changing the regulator or anything unless you start having problems with starting or not keeping up with demand from the system.



If you have any high amperage items installed on your truck. You might want to think about installing another ground strap from the engine to the frame. The smaller wires are good for normal loads. But if you haul a trailer or use a winch. Then the larger cable from the engine block to the frame would carry a better more direct path to ground.



The grounds for you dash board are located behind the OD/cargo light switches. They are screwed to the metal bracing on the back side of the dash. The are three wires mounted at this point on my 93.