So driving today...my radio slowly looses its volume gradually going down and down and down till there is no sound at all...I think wierd, then about a minute later I glance at the FP and it reads Zero (although I highly doubt that is the case) and about 15 minutes later I hit a turn your headlights on strech of road and so I turn them on but there is NOTHING...I have brake lights turn signals running lights just no headlights.

so tommrow I am gonna try to figure this electrical mess out....ohh yea no overhead either....

I think they are all related...

with the radio it isnt a fuze because the head unit is still on..its like the remote lead to the amp is not carring the signal because the amps wont turn on..

here is my first guess...DRIVER SIDE BATTERY..and here is why.

LMC headlight relay harness,Quad commander, Battery positive for the amps all hooked up to that battery.

Throw out some ideas..any and all welcome.

Thanks

NCA

 

Don't see how it could be just one battery since both are wired in parallel.
It doesn't make any difference which battery the add-ons are connected to.

 

I lost my headlights twice on my '98. It was a burned up dash switch both times - that item is a huge weak spot in the 2nd gens.

The reason I suggest this, is I doubt all those things you listed are connected directly to battery positive or they will be on all the time. I have a feeling they are connected on the other side of the dash switch so they get "keyed on" power. Obviously, I would have to see it in person to know for sure.

For example, amplifiers are usually hooked up fused direct to battery positive, however they have an internal relay that turns them on with the "key on" position. Same thing with the Commander - it's keyed on power or you'd have the display on all the time. Many installers use the key on hot wires from the light switch because they are some of the easiest to get at.

If you said you lost park lights, tail, and signal lights, I'd point you toward the column dimmer switch as those are the next common things to go for those problems.

Hope this narrows your search.

 

fetus

I would be right there with ya in your thinking...but I already had the swich burnout problem and thus the reason for the LMC headlight relay and a brand new headlight and dimmer switch install..while i had the dash apart I looked at the wireing and i didnt see a bad wire melted or otherwise..

I wonder if I have a bad ground somewhere.

I havent had much time to look at the problem as I am on shift at the FD.

I hear ya about the amp and commander and all..the amp gets its signal to turn on from the remote lead comming from the back of the head unit and the commander from the lead connected to the fuze box.

my thing about the battery, was a guess and only that. it just seemed to be "TOO" consindental that they all are hooked to the same battery.

I dont get it.

NCA

 

Did you check the alternator output? Battery voltage?

 

havent checked those yet...

is there a way to check the alt. output with simple tools while it is on the truck...

only way i have done it is yank it and take it in to have bench tested.

load test on the batteries, I can do simple enough.

thanks, to be honest I hadn't even thought ALT.

I was thinking ground, fuze, weak batteries...although the batteries are really pretty much new one is about 8months old and the other is about 3 months old.

come to think about it, i did let the truck sit for about a week while I was in AZ. and when I got back it had a little lag when starting it...kinda like that long crank then ignition.

but I am gonna take your advice and check that ALT. Thanks Xtoys

NCA

 

That's my thought too. For a quick test, with the engine running, use a voltmeter to measure voltage at the battery. It should be somewhere in the neighborhood of 14 volts. Now, with the engine still running, turn on a couple of big power consumers, like the high beams and the blower on high. The voltage should remain the same, about 14. If it is down in the 12s, your charging system needs some diagnosis.

 

thanks torque..

I figured that the volt meter on the dash isnt the most accurate but as a side note it does read in the neighborhood of 13.5-14 while running...

now that is not at idle as i have not looked it was while on the freeway which is the last time I remember looking...so while doing high RPMS it is possible to keep it up there but at idle or lower RPMS I guess it would or could be lower if that is the bug chewing up my system.

also...I was under the impression that you did not want to take a reading at the battery with the engine running...cant seem to remeber why but I have always checked voltage with the key on, engine off, while at rest...

forgot to mention.....the FP on the commander is the ONLY function not properly working...the commander itself is ON and I have Boost, EGT, and H20 showing accurate readings...its just the FP...now we all know the problems the sending unit has and this is why I feel (almost 100 percent positive) I have good FP and I feel it is something do do with a GROUND...because there have been issues surrounding GROUNDING the FP sending unit...at first it was use teflon tape with the sending unit..then it was dont because it is a self grounding unit..then it was back to using it...I personally have done tests and I run without teflon tape and have added a needle valve which has helped the FP sending unit a lot....and I have a backup sending unit brand new in the garage that i will be putting on tommrow...as well as testing the FP with a mechinical guage...

just wanted to add that.

NCA

 

What torque recommended is a pretty simple, and effective way to check. I can't really explain the symptoms, but I have seen some WEIRD stuff happen when an alternator and/or battery goes bad.

You can go to autozone, and they can load test the alternator for you. It's not an exact science, but it'll give you a better idea than checking it yourself.

Let us know what you find, this one has me intrigued...

 

Now after reading more of what you have typed, checking ground and charging system seems the more probable place to start.

I am a little concerned on the charging system and battery issue you mentioned by stating they are different ages. Because they are hooked parallel, if they're the same kind of battery, that should be fine, however I've seen weird issues when batteries are used together that aren't the same type. Generally, batteries that are used together, should be the exact same kind and changed at the same time. My Dad wrecked the charging system in his motorhome by not using batteries with the same ratings.

At least you have some good ideas going. I'm curious about the results as well.

 

festus..

intresting you said that about the same rating batteries...

because they are the same make...I made sure of that, they are the same group....but

one (the older one, older by a few months) was purchased at a walmart in So. Cal and is (not 100% certain, going off memeory, but close enough for the discussion) like 875 CC amps and the other the newer one was purchased at my local walmart, like i said the same group but is like 845 CC amps...

while they are off, they are not off my much I know its like 25-50 CC amps...when i carried out the new battery and put it in at the parking lot...I noticed they CC amps were off, so i went back in and confirmed with the shop people that they recommeneded the correct battery...they looked up my old battery and said that the manufacturer replaced the battery with this one and it should not show any difference...

HMMMMM....

still gonna test the Alt. and load test the batteries...but hey...you never know..

do you all think the FP guage is isolated and not part of the larger picture..being that the FP sending unit is know to be bad...it seems that I am the only one that has not had issues with it..mine has lasted from the first shipment of Commanders that ever hit the street..what like a year and a half now or something...maybe it finally gave out...being that the rest of the quad commander still has power????

it would seem that both amps, and headlights/highbeams would fall into the HIGH AMP draw symptoms of a failing charging system?????

although off the top of my head what just hit me is the recommendation of running the blower/AC/defroster for a high amp draw...I ran the AC yesterday, the heater and defroster this morning and had NO problems...but i didnt check the voltage guage while it was running...

ohhh well....I got things flying into the head right now and really I am just spinning wheels...I am lost.

NCA

 

competley a side note here...

but I am probally stepping up to a 3rd gen very soon...

not because of this or any other issue...because this truck except for this issue right now and new rotors and pads in the near future (its time, original rotors starting to show warp) this truck RUNS LIKE A TOP. only 132K on the clock and she has NEVER EVER NOT STARTED...

but for the simple and ONLY reason...I kinda am falling for the 3rd gen BODY style...

I know that is a weak reason...

but a good white quad cab long bed with a 4" lift and 35-37" tires is LOOKING SO GOOD in my MIND.....lol

my luck, I will sell this truck which is an absolute pleasure to drive and has given me ZERO problems and I will get an absloute nightmare with nothing but problems...lol

ohhh well....

NCA

 

Thanks for the ideas and sugestions

You ever get yourself worked up about something and forget to check the simple stuff first????

Well I did...

as it turned out...

batteries at rest...12.2 volts
batteries at idle...14.1 volts
batteries at idle with lights, radio, AC MAX, and interior lights...13.8
batteries with all the above and a high idle of 11-1200...14.1

still stumped...checked the ALT output...based on Hanes..good

now on to the fuzes...ALL GOOD.

still nothing...

Check the AMPS...wires GOOD. GROUND GOOD

check the QUAD FP against a BRAND NEW ONE...thats not it.

CHECK the QUAD COMMANDER FUZE tap...thats not it...

Now it comes down to the back of the deck...(if you cant tell by now, I am not thinking this out logicly, just jumping around checking this checking that god it frustrated me) so I pull off the dash and pull out the deck...thats not it all the wires are still either crimped or soldered good.

Ok jump back under the hood...

check the batteries....ohhhh theres something....undo driver side battery positive and lift it off...and there built up corrosion that wasnt visible from the top....brush and powder and hook it back up nice and tight...check the neg and it was tight and much cleaner...same for passenger..hop back in and turn her over....BINGO GOT MUSIC

GO to hit the lights and NADA...DANG.

so now its just two...FP and lights...I re think my scatter brain method and decide to focus on the FP...first thing I decide to check is the neddle valve and sure enough the **** thing is backed way off....so i slowly tighten it down and check the commander and sure enough when I get her close to being between a quarter and an eighth the FP starts showing up....rising from 0 then 6 then 14 then 18 then peging at 19 at idle...go for a little drive and she is rock solid...19-18 normal driving..give her some go pedel and she slips to 17-16 and hammer her down and she dips to 15-14

back at home I diecide to look at the **** lights now...so i reach down there where the LMC harnes plugs in cuz i wanted to check the blubs and sure enough the **** harness is half on half off....push it in here the pins catch and snap...turn the light switch on.....LET THERE BE LIGHT...

so...lets see...STEREO...BATTERY POSITIVE
FP....NEDDLE VALVE TO LOOSE
Headlights...NOT PLUGED IN

Man talk about work me up for nothing!!!!!!!!!!


thanks again all

NCA

 

Congrats on figuring it out. Hard to believe, 3 different symptoms caused by 3 totally different problems, all at the same time. These things sure make diagnosis a challenge. Glad you got it solved.

 

you live in california and want to go to a 3rd gen get one pre 06 due to our new smog regs comming in jan beter yet keep the truck with out the cats .