I just re-read post 36. I see you just had the switch out, had thought you had changed it. I thought there was a security screw on that? And it runs fine for 1/2 an hr or so, then the voltage drops. All four surfaces on the battery shiny bright lead? (no grey crust). Also the cable off the back of the head to the firewall. You know, a bad connection sometimes get's hot. If you crank a cold engine, and the end where the ground cable connects to the engine get's warm, bad connection.

Belt is tight...connections on the Alternator been checked? Voltage dropping, that's where it comes from.

That actuator business sounds like a real pain. JY? Grab a switch while you are there?

 

I remember your earlier post & did do part of that. I used cables as a extra ground to the motor, but I did not try it to the body as well. As soon as I can I will try it. But fyi - I took off all grounding bolts, from firewall to back behind valve cover, from battery to body & also down by the dipstick. I wire brushed all connector bolts & surfaces then shot them with starter fluid to insure there was no oil residue as well. So unless there is another ground I am unaware of the only thing that could be bad for grounding is the wire itself, mybey broken internally or something but nothing jumped out when I examined them.

 

Ya, the acctuator has been an experience I will not soon forget thats for sure!! I am going to the yard tommorow to get the part, can't make it today. But I have checked the belt for play & I will admit for the alteernator I have only looked at the connections. But I figured they are O.K. due to the 13.78 volts at the battery. But I am going to pull them & clean them as well now that you mention it, I mean it can't hurt at this point, right!

 

the center distributor wire runs to a little black box to the right, below that box should be two ground connect bolts.

 

Think I had a break through! Did what you said grounded from - batt terminal to shiney pat of motor & body. Started vehicle & 14 volts on gauge with motor ideling. Next turned on lights, rear defrost, front & rear wipers & air conditioning.
Volts started dropping......put meter on battery & showing 12.5-7. turn all of that off & I have 13.7 volts at the battery.

Next I pulled both cables off the battery, then took a post clener to it (Just in case), then did everything again with the same results. So I pulled both of the extra grounds & all voltage is the same. With all the stuff turned on 12.5 volts at the battery (running) & then I turn everything off & the voltage will climb slowly to 13.7 at the battery.

So is it that the battery can't handle the load or altenator I think I just about have it guys!!!

 

Fantastic! I'm not cleat on exactly what you found with the grounds, but I can live with that, just fix it! I almost always chop the probes off a new meter and put little clips on there so I can actually use it. You can set it on ohms, (200 scale maybe), then hook it between something, (engine and battery neg. for example)(Bat Neg-body), then poke around, jiggle things. See if bumping things around changes the reading. Mine is less then one, anywhere.

It's tough on the internet. Sometimes I think if I was there I'd find it in 5 minutes. Easy to say though! I hear over and over, "the battery terminals are fine". Then "Oh, heck I found it, the terminal wasn't connecting". I can't tell from here who actually cleaned them to shiny inside the clamp, and the posts. That thin crust can look perfect...gotta shave it with a pocket knife or something....Pardon me...venting...They really mater..Of course you actually got them clean.

If the belt is tight, the connections are good, and the voltage isn't, I'd be looken at the alternator. A battery would need to be really crapped for it to keep the voltage down.

Since in my experience an alternator will usually crap all the way, I'm thinking the belt, or a connection. I'm not sure, but the alternator field might be one of the heavier currents the PCM needs to handle. (or maybe it just controls something IN the alternator that then provides field current to the rotor). In any case our Renix have a gang of important grounds on the dip-stick tube mount. That PCM in that 99 grounds somewhere over there as well I believe. Myself, I wouldn't buy a new alternator without checking/cleaning that. Also you might 'Mcgiver" a jumper cable ground to the alternator it's self for a second in case it's not grounding. I just had that happen on my little Case dozer. Couldn't believe it! Firmly bolted on there, and Zero ground. Guys here have seen that on starters also.

I just tried to take a look at my alternator...forgot how buried that sucker is. I might start it (cold), then try to get my finger on the Pos. post. A bad connection really can get hot. If you hear a sizzle then smell your finger burning, you found something.

If the belt is tight, the connections are good, and the voltage isn't, I'd be looken at the alternator.

Did it start with the key, or did you jump it?

 

I'll check this today when I get back from the junkyard to get the acctuator.

 

I had to start with a screwdriver in the new starter switch, can't get the acctuator intil later today. As far as battery goes when this first started the neg clamp was loose & was not able to clamp any tighter. So I purchaced & new one. Pulled of the positive side & cleaned both posts with a battery post cleaner. Then cleaned inside the positive clamp & installed the new negitive clamp. But now that you say something I did not clean the inside of the new negitive clamp. But being new??? I will today just in case.

 

Sounds like you got the original problem solved - the switch - after you've been led all around the bush.

Once you get it back together it should be good to go.

Battery connections ALWAYS must be clean and tight.

BTW the starting circuit is totally separate from everything else. Lights, charging circuit etc are all unrelated. You had 2 problems.

 

Doesen't really sound like your problem, but might as well be sure. I guess that thin crust/oxidization forms with the gasses from the battery interacting with the charge from the battery. I don't know the actual "mechinism", but it coats every micro spot down to the last. So thin, and often grey, it can look pretty good. When you hear/feel your blade scraping something hard and brittle, it's not lead! Make sure that belt is tight, or change it if you want to have a spare.

I recently installed a new belt, then had to go back and tighten it a week later because my voltage was dropping with a load on it. It wasn't exactly a mistake, I like it as loose as possible to reduce bearing wear on everything there.

 

New belts always stretch a little at first. That's why if you look at the FSM there are 2 different tightening specs for new vs used.

 

Thanks Rrich, I didn't know that. Stands to reason of course. I'm sure mine is looser than spec, but good to know if I were to "send someone out"

 

Yes there was 2 mabey even 3 different problems, here is the final update on this thread.

Picked up Ignition accuator at JY on Friday & Installed, Jeep fired right up! So put everything back together took it for a short ride but still the volage dropped on interior gauge. So I did what was posted, pulled alt connections & wire brushed everything. Next found the last 2 grounds (mentioned above) that are under the distributer cleaned them all up as they were caked with old crusty oil. Sarted it up & took another drive & NO VOLTAGE DROP So put battery on charger (to make sure of full charge after all this) & told my son he could use it for work.

He leaves for work & 15 min later I get a call from him, he says on the way (to the gas station he is now stranded at) the speedometer dropped out completly & the tach shot all the way up but he kept going to the station as he did not want to be late for work. And now it won't start al all...same symtems of no click or anything.

So yesterday went to station, tryed to cross jump again at the starter & it would not even do that. Put a meter on it & read 12.58 at the starter. At this point I am completely at a loss, told my oldest son that was with me just leave it & we will have it towed to a garage I am done with the @@###!*! thing! He said come on Dad isn't there something we can do think Dad he can't aford a garage bill. So (now that I was guilted) I said I can try one more thing. I had he get in & turn the ignition got iunder & smaked the starter....starts right up So to shorten thi up (ya right) got it home intalled a new starter & bingo seems now to be all good.

So THANKS to everyone for your help on this one it was quite challengeing but everyone's advice helped along the way, so thanks again.

 

I'm afraid you aren't done yet!
A starter with worn/stuck brushes can start working again with a good thump on it. But the speedo and tach doing that cannot be affected by the starter. 2 separate circuits, 2 separate problems.

Indiana - lots of humidity?

Pull the top section off the PDC - relay box. I'll bet the connections underneath are corroded. Use contact cleaner to get the corrosion off (or Taco Bell hot sauce - it's the vinegar in it - slightly acidic) to remove the corrosion. After a good cleaning, neutralize with a mild solution of baking soda and water.
I'm not sure on yours, but I think there's a big connector on the firewall where wires go from front to inside. Open that connector and clean it too.

And try something - sometimes a battery cable corrodes inside where you can't see it. Pull the coil wire out so it won't start. Crank it for a minute or 2. Feel all along both cables -- if it has a resistive portion inside that spot will get warm. Most likely cable to go bad (in this case) is the negative one.

And - run another cable - one you add in addition to the one already there, from the (-) post to a good body connection - different than one already used.
Since both the speedo and tach acted up, it's something in common to both of them.
Radio and heater blower, even headlights may also be affected but you didn't notice.

Problems like this are a real PIA - and expensive for a shop to trace down. How do you charge for a bad connection that took 5 hours to find? $300 to find it, $1 to fix it? We tried not to get involved with "no win" problems like that, but sometimes it's unavoidable.

Let us know on this thread.