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About Gene

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    Comanche Aficionado

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  • Gender
  • Location
    Western Maryland
  • Interests
    1988 Comanche longbed 4.0 5 speed 4 WD I have had this since it was new!

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  1. Gene

    Alternator Wiring

    I probably should have realized that you do not question the electrical knowledge of someone named Ohm... Gene
  2. Gene

    Alternator Wiring

    Actually looks like this is addressed in post by Ohm above...sorry....thanks Gene
  3. Gene

    Alternator Wiring

    Hi Jeep Driver, Not sure about our Jeeps with a gauge, but at least some applications must have a working dash light. Please see page 87 of this link. https://books.google.com/books?id=3q85p56_PxIC&pg=PA87&lpg=PA87&dq=OLDER+GM+NOT+CHARGING+BURNED+OUT+INDICATOR+BULB&source=bl&ots=nhJHY8UN0K&sig=qn_1iNBXbtp9oTwxuaVQpIatXhM&hl=en&sa=X&ved=2ahUKEwivgZygmI_eAhVMjqQKHdRmCDg4ChDoATADegQIBxAB#v=onepage&q=OLDER GM NOT CHARGING BURNED OUT INDICATOR BULB&f=false Your thoughts? Thanks Gene
  4. Gene

    Alternator Wiring

    *****EDIT The following applies only to vehicles with an indicator light NOT vehicles with a voltmeter**** Similar discussion
  5. Gene

    Alternator Wiring

    *******EDIT: The below post only applies to vehicles with a battery light NOT to vehicles with a voltmeter****** Take this of the grain of salt… This is from memory, decades ago… Your 88 uses a GM alternator. With the ignition switch on, BOTH the yellow, and the tan/white wires, should show voltage. The yellow comes directly from the ignition switch. However, the tan/white passes through the voltmeter, or idiot light, and then goes down to the alternator. If this wire has been disconnected, or the idiot light burns out, this wire will show no voltage. The alternator will not work. For test purposes, or even as a long-term repair, you can put a 10 ohm resistor in series to mimic the light/gauge. So tap into the yellow wire, connect a 10 ohm resistor, and then connect this to the tan/white going to the alternator plug. I forget all the details, but I remember "back in the day" in GMs that if the idiot light burned out, the dash would have to be pulled to replace the light for the alternator to work. See page 24 of this manual for details http://www.bteventures.com//mj1988electricalmanual.pdf Now, having said all this, the more I look at the diagram, the more confused I get. I am not sure if everything I said above is true, but I am reasonably sure that if the tan/white wire does not have voltage the alternator will not work. Hope this helps! Gene
  6. Hi ratty, Couple of ways to do this. These techniques will generalize to anywhere in the vehicle. The first way is to realize that, if all the connections and cables and wires are good, voltage anywhere on the hot side of the circuit should be the same. So check the voltage between the positive battery POST and the negative battery post. Then check the voltage between the positive battery TERMINAL and the negative post. If there is any difference, then there is high resistance where the terminal meets the post. Then, follow the smaller wire a short distance over to the relay center. Check the voltage from the end of the cable to the negative battery post. Again, the reading should be exactly the same. You can accomplish the same thing by putting voltmeter leads across the suspected cable. This would be done with the cable connected. Put one lead on the battery positive post, put the other lead at the cable end. If everything is good, you should be reading zero volts. If there is any resistance in the cable, then you'll read some voltage. The other way to test is to use ohms function on the multi meter. This must be done with at least one end of the cable disconnected. You would just read ohms from one end of the cable to the other. If it's good, it should be zero, or very very close to zero. Hope this helps! Gene
  7. This thread has been a little confusing. As I read it, the 12 V or less is at the dash gauge, but 14 V was being read at the battery. Why don't you turn the headlights on or put another load on the electrical system, until the dash gauge reads 12 V. Then use the multi meter at the battery. If the voltage at the battery is about 12 V, then you are very likely dealing with a bad alternator. However, I suspect that the battery voltage will still be okay, even when the dash gauge is low. This would indicate that the alternator is fine, the problem is with the dash gauge itself, or more likely with wiring or ground somewhere else in the circuit. If I misunderstood the situation then ignore all of the above. Gene
  8. Gene

    Emiss Maint

    There are guys on this forum ( HOrnbrod, cruiser, eagle, and Pete among others, certainly many more) who are walking encyclopedias of Jeep. Their knowledge, and willingness to help, are exceptional. Gene
  9. Hi Myles, You really, really, really need a voltmeter. You can get a cheap one for about $10. The voltmeter on the dash is notoriously unreliable. I agree with everyone so far, most likely this is a bad battery. I think the strategy of pulling it and taking it to be checked make sense. However, what does not make sense is that your vehicle dies. As Eagle pointed out, a bad battery, by itself, would not cause the vehicle to die. So there may be two separate things going on. I think it's possible that the vehicle is overcharging, and that the dash gauge is not registering properly. This could kill the battery, hence two problems. Voltage of a fully charged battery, engine off, should be around 12.8 V, give or take. When the vehicle is running, and the alternator is putting out electricity, the reading should be around 13.8 V. Please let us know how this turns out! Gene
  10. This seems most likely. Bad ground somewhere in left front. Gene
  11. Hi Paradise, That voltage difference goes along with a high resistance connection. I would try changing the terminal (or whole cable) first. Gene
  12. If you have a helper, then put the voltmeter on the battery posts, a fully charged battery should read about 12.5 V or higher. Then have someone turn the ignition key to start. If the voltage goes way low, perhaps five or six volts, then the battery is defective. If the battery voltage stays high, not really dropping below 12, then look elsewhere. Bad starter solenoid would be one possibility. Gene
  13. Gene

    LED Florescent Bulbs

    Hi Don, You actually don't have to change the fixtures, the ballast can be eliminated. In the second link, click the "general instructions guidelines" link. Of course, the more fixtures there are, and the longer they are on, the more important this becomes. Gene https://insights.regencylighting.com/plug-and-play-or-ballast-bypass-linear-led https://www.earthled.com/collections/t8-t12-led-fluorescent-replacement-tube-lights-that-bypass-ballast-rewire/products/luceco-led-fluorescent-replacement-tube-4-ft-18-watt-ballast-bypass-direct-wire?variant=2174807620
  14. Gene

    LED Florescent Bulbs

    Hi everyone, I believe that, if you really want energy savings, the LEDs have to be wired directly, eliminating the old ballast. The ballast, if left connected, still consumes quite a bit of energy. It seems like one of the local "scams" is to promise significant savings with an LED update, but then just install LED tubes in the fixtures, without touching the ballasts or wiring. It's quick, but really doesn't do much in terms of energy efficiency. Gene