99 tahoe no electrical power

[NATEaz208]

hello all , i had an issue a year ago with my tahoe i started it one morning and it had a hard miss and a code for random missfire . since i have bought it i have been playing catch up on maintence from previous owner i have replaced cap rotor plugs wires and has new fuel pump and and fuel filter. the previous owner said it had a newer engine from local dealer in it . however stuff i took off didnt look new ...anyhow today i got a compression tester to make sure i have a solid foundation, i am having issues with trying to do a compression test ,i took the duralast battery that was in tahoe and got a new one under warranty ( battery dead , truck has been sitting for almost a year) and i installed new battery in my sierra today and took the old battery from the sierra to crank the tahoe over for the compression test however i dont have any power in the truck no interior lights ,nothing when i turn the key(battery has 12.56 volts) . i took the battery out of my saturn just to rule out a bad battery , same thing no power . i checked fusues under the hood all ok .i also checked ground and the fuse panel in the dash on driver side. the tahoe didnt have this issue before i parked it?? any pointers would be appreciated

if the compression test comes out ok , i have read that intake gaskets or the injector spider are common issues on these vortecs would i be better off just doing the lower intake gaskets and the spider at the same time? just to save me from doing either down the line..

 

[Tex99Tahoe]

Hey NATEaz208, welcome to the forum.

I'm still learning about my `99. Found bad grounds. Might want to recheck yours. My master ground lug on engine lower right front was finger tight, and the braided engine/chassis/frame ground at the lower right rear, on the frame, was totally corroded.

Saw a pic here somewhere that showed those braided grounds cut, possibly during engine pull for a previous owner's engine rebuild. Probably caused problems, maybe that's why it was sold.

Then, using a multimeter, check for voltage at the main power lug on the driver's side master fusebox. Might also check fuses in there too...

 

[NATEaz208]

thanks for the welcome, i went out again today and rechecked all my ground all are tight braided cables arent damaged ... recleaned cables with wire brush , didnt even have a spark when i touched cables to battery, could i possibly have a bad positive cable ??? i have no power to the fuse / relay box under hood.. reconnected all connectors on harness ... still nothing , im just beside myself this truck had no electrical issues prior to parking, also checked for any signs of damage from pests and none found. could i possibly have a bad cell in the battery that i took from my sierra , had no issues with it though...

 

[Tex99Tahoe]

Sure sounds like a bad positive cable allright. Hard to imagine, such a big wire like that...

 

[NATEaz208]

well for 8 bucks at oreilly i will pick one up soon and give that a shot and cross my fingers ...

 

[Tex99Tahoe]

Might could do some more quick/simple tests. If your voltmeter's clipleads are long enough, put the pos lead on the power lug at the fusebox, and the neg lead on the battery's neg terminal.

If you get no voltage, then that battery hot wire is probably bad.

But, if you DO get voltage, then move the neg cliplead from the battery negative to the frame, then the body, and then the engine. See if any show no voltage, and if so, that would be one of the grounds...

 

[NATEaz208]

i will definetly give that test a shot , i think my leads may reach if not i will get some wire to connect to wherever i need to thanks for the tip

 

[NATEaz208]

did the test this morning and no power at distribution box so i will try and get a cable over the weekend

 

[lesterl]

Find the wire that feeds from the fusebox over the radiator and follow it to the battery, IIRC there are 2 cables to hook to battery +, make shure you got 'em both hooked up

 

[NATEaz208]

i am an idiot, the cable that runs nover radiator was not connected traced from distribution box found it coiled up in corner ....go figure everything works. did the compression test all cylinder were pretty close, the lowest was at 120 the highest 145 all other were around 130 psi .. is this low all way round or should i not worry since the are all close and above 100psi? if ok any pointers as far should i pull intake do lower gaskets and pull upper and look at / replace injector spider .. thanks for the help

 

[lesterl]

Nice..... Compression is kinda lopsided, put a teaspoonfull of oil in the low cylinder and see if it comes up, if it doesnt, then it probably needs a valve job.....