91YotaExcab

all 3 of these lights have been on for about a month now and when i bring the rpm's up they go away and when they go back down they come back on. Today my battery died. Its about 2 months old now and works fine. i brought the altenator to a shop about a month ago and they said that was fine. But i think thats what it has to be. when i put jumper cables to it it starts right up. Then when i remove them it dies out. Is it the Altenator? Or am i overlooking something?

abecedarian

Check your engine grounds. Sounds like a ground wire from the engine isn't 'grounded' properly.
You can check the alternator by placing a voltmeter on it's output terminal and the case or engine block- should read at least 14.5 volts.
The a/t temp sender and oil light both use a reference to ground as well to create the conditions that light the lights.

91YotaExcab

where would the ground wires be?

abecedarian

Follow the battery - wire to where it goes. There may also be a wire from the engine block to the chassis somewhere.
You can, however, check the ground by using jumper cables: clamp onto the engine somewhere and clamp the other end to the battery - terminal. If everything starts working, you know it's a ground problem.

abecedarian

now that I think about it, it is possible that the diodes in the alternator are bad- this could cause the problems you are seeing, what with the lights going out at higher RPM's.
How to test? --> take it out and down to the shop for bench testing.

91YotaExcab

Do i put the cables to both terminals? and if this is the prob can i just drill a hole on a non improtant part on the engine and run it to a ground source?

91YotaExcab

damn i was hopin its just a ground... o well altenator is easy but im just cheap. thank you for your help

abecedarian

Connect just ONE clamp to the engine block and the other end to the battery -. let the other one dangle. You could also use an existing bolt (or unused) to run a wire from the chassis to the engine.
I was thinking of a way to test the ground theory and using one wire in the jumper cables to connect the engine block to the chassis seemed easiest.

If you do that and the problem goes away... bam... bad ground.

91YotaExcab

GREAT now i just need a jump start...

abecedarian

If the battery is newish, then letting it set an hour or so should allow it to regenerate itself enough to start the truck.

91YotaExcab

i kno but i wanna do it now!

abecedarian

rofl...
maybe a few 9v batts in series?

91YotaExcab

ok i tried thegrounding out thing. i didint work so im preety sure its the altenator ive read a couple other threads now where that was the problem with all the lights comming on. And if it was a ground i dont see why when i rev the balls out of it the lights would go off. And one more question. when im standing at the front of the truck in front of the battery about a foot up and a little to the right there are 3 electrical connecters that arent hooked into anything any clue what these might be? there used to be a plow on it but all the wires for that are accounted for. any ideas?

abecedarian

when you rev the engine, it's possible that the output of the alternator (in spite of a bad diode or two) is providing enough DC power to run the system, albeit not at the optimum voltage nor enough to charge the battery.
With bad diodes, you might get enough usable voltage to light the bulbs (bulbs don't care about AC or DC... they just want current) and just enough DC volts to run the ECU.

That is why I mentioned bench testing it earlier.

91YotaExcab

i lack the tools to test it and now i have no car to get to the parts store tomorrow... i bought a toyota so this wouldent happen lol

abecedarian

On the up side: when you fix it, you'll have a good truck to last a while... as long as you take care of it... unlike what the previous owners did.

91YotaExcab

as for takinbg care of it at least the PO was smart enough to frequntly clean the frame. its almost spot less i couldent belive it when i looked underneath it. Its also was used for light plowing and hauling but only has 98k on it now. ive done a full tune up and it runs almost perfect. it does sputter or idle rough once in a while i tried replacing the tps too but that didint help. i think ima clean out the throttle body aswell i just read something in a link you posted elsewhere that says i should have done that before i tried replacing the tps. any other tips?

91YotaExcab

i replaced the altenator and the lights are still on... any clue?

91YotaExcab

I found the problem! it was exposed wiring from the PO. When he attached the wiring from the plow he did no tape off some of the wires to the head lights. Im scared what else im gonna find that he did half ass now. but the low idle and dash lights have gone away finally