electrical problems-87 2wd auto

[p7387]

strange problem occurred all at once.
here are the facts--

truck always started without a problem even when only used periodically, never any indication of a weak battery.

took a 2hr round trip without problems, upon return home the truck was parked in the driveway and turned off, just a few moments later i attempted to start it again and the battery was dead as can be. the starter couldn't crank and the headlights were totally dead, the only electrical features working were the interior cab light and the ignition "buzzer/ck engine/seatbelt " cluster lights but oddly enough they were fading in and out from high to low.

is this indicative of some serious short or electrical problem?
any ideas would be great.

thank you

[Dragon]

Yes the Fading from High to Low indicates a substantial drain to the system, it is attempting to start ,but it is too weak to....   I would suggest checking all of our Connections and the Battery, check your grounds to make sure they have sufficient contacting area....  If you have added any equiptment to your system recently, check all of those connections, check the Fuses for those items....

Almost sounds like your Alt Regulator(Yep even internal one can be toasted, and the rest of the Alt is just along for the ride) is fried, and your battery stuggled to keep the System running properly, but finally is too weak to take the full draw when you attempt to start it....
If all of your connections and such have panned out, I would recommend you remove your battery, and take it in to be tested....  Even if your Battery comes back as being bad, it is possible that your Alt or another part of your system is actually at fault(If a new Battery gets your truck started, I would take it to have the Electrical System Diagnosed. That way you can be sure it wasn't anything else)....

[VileZambonie]

did you try to jump start it?

[joesgarage71]

First thing I would do is check the Battery cable on the starter.

[p7387]

thank you

i had a chance to get into it today, i checked and cleaned all the battery connections and ground to body connections, everything is good. i also checked the battery voltage with the motor off and it was reading 12 volts.

next i attempted to jump it, all the lighting was working with the jump cables connected and there was no interior light fading as i noted earlier however it just was not getting enough power to start, just the clicking sounds. next i connected my sears battery charger using engine start mode and got the same result-clicking but not turning over. in both cases i let things sit for a bit in hopes of getting some juice into the battery. since i could not get it started i could not check the alt output.

? - why would i still be having starting problems if the battery is reading 12 volts ?

? - why is it not cranking over in spite of jumper cable connections and than the sears battery jump ?

my next step is to replace the battery but i would like to first understand the logic behind what is going on. there have been no recent electrical additions or connections to the truck.

thanks for the help.

[Lt.Del]

I'd say the starter needs to be looked at, probably the solenoid/switch.

[VileZambonie]

The battery needs to be charged and load tested. 12 volts means nothing if the battery is bad. You probably need just a new battery

[197]

Whats the exact battery voltage? 12.6, 12.4, 12.2???

[VileZambonie]

That will depend on state of charge and again - voltage will not tell you if a battery is good or bad.

[197]

True, on some cars it wont even attempt to start with voltage under 12v.

[p7387]

i went to autozone and replaced the battery with a new #75-dlg.
after installation i checked the volatge with the motor off and it read 12.8v
after starting the motor i checked again and got 14.8v  --  are these numbers within acceptable range? or is 14.8 volts on the high side?

thanks

[choptop]

i went to autozone and replaced the battery with a new #75-dlg.
after installation i checked the volatge with the motor off and it read 12.8v
after starting the motor i checked again and got 14.8v  --  are these numbers within acceptable range? or is 14.8 volts on the high side?

thanks

14.8 volts does seem to be on the high side. I prefer no more than 13.8 for a 12 volt system. This higher voltage could easily bake your new battery. As far as to why it would not jump off with the battery charger or jumper cables, Neither one is reall capable of handling the ampacity required to start the engine. There isnt enough contact surface on the clamps to carry the load, and most dont have enough cable size to carry the load. My cables are built with 1/0 cable and are very heavy, but I built mine. Most storebought are no larger than 2 gauge, and thats for high dollar cables.  That being said, I imagine your original battery was toast, possibly due to the high charge. In order to boost a vehicle, the batter has to be able to hold some charge, even if just temporary. You said the voltage was 12, but would not start it. This tells me the battery was shorted internally. If a meter was put on the battery when it was cranked ( or attempted) the voltage probably dropped to 8vdc or less immediately. I would definatly get the alternator checked, I think 14.8 is too high, and you are on your way to replacing the battery again.`

[VileZambonie]

A battery after it has been running will have a surface charge. This is usually over 13 volts. To remove the surface charge turn the headlights on for 15 seconds and then let the battery stabilize. Check your meter also, short the leads and verify it reads zero on the DC V scale. For a CS alternator 14.8V is not over charging.