Hey I've looked back almost to the first of the year thru all the threads and I didn't find something exactly similar.

I have 2 Chilton's and neither has the proper year wiring diagrams for my V6 4.3l vortec. Anyway, the battery will drain usually over a day if I don't use it, and if I use it every day, usually about once a week the battery goes dead. It reads 12.6 - 12.8V at rest and running it will read 14.3 or so. One year old alternator and 3 year old battery.

I pulled each fuse out and tested every fuse slot; everything was "0" with door open except #10 "crtsy loop" and #15 "rdo batt" which both read over 12v. I even slid a small wire into each slot with the fuse in and closed the door and they both read the same.

Nowhere can I find out what those two slots are, though by the letters they look kinda like courtesy loop and radio/battery?

How do I check a relay in the lighting system or any place? I need the wiring diagrams.

Also, can't find anywhere what the "key off" electrical drain should be.

If some one could lead me to the current/proper diagrams for a 99 4WD Blazer. I've been out of work for nearly a year full-time so money is tight and I can fix gas and pellet stove electrical problems but not this. Frustrating! Thanx.

 

You can't track down an electrical drain by testing voltage. You need to test the amp draw on each circuit.

I have posted it before in threads very much like this. The steady state amperage draw should not exceed 35mA. I say steady state because there will be a period of 2-5 minutes where some of the modules in the truck will still be fully or partially awake. The amp draw may be over 2A to start off. After 30 seconds or so it should drop to around 1A. From there, it should drop down to below 35mA.

Start at the battery and see what your current draw is. Then move to the individual circuits.

Have your battery load tested as well.

You don't need wiring diagrams until you have identified the circuit(s) that is(are) at fault for the drain (if you find one).

Isn't "exactly similar" a contradiction of terms? LOL

 

hey terbates if you have lighted vanity mirrors check to see if the hinges are broke on the cover this will allow the lights to remain on . also keep an eye on your dome light to see if at times it will not go off when you shut the vechicle off some have a time delay. both are common problems on these wonderful vech

 

You may also want to have your battery tested. I realize it is only 3 yeas old but I would have it checked anyway... testing is free at most auto parts stores. You may also want to check your conection at the starter as a loose or bad ground there can cause the drain. also a bad voltage regulator (even in a new alternator) can cause a back flow of voltage after you shut off the truck but you will continue to charge the battery while you are driveing. Sometimes problems are simpler than we think when we get frustrated.