My daughter was driving to work and the Blazer just dies. She said there was no sputtering or hesitation, it just died instantly. So I get it home, I'm not hearing the fuel pump so I think it's obviously that BUT, I also checked for spark at the coil and there's none. So now I'm thinkin' along the lines of a major electrical failure. Is there anything that might shut down both these systems?

 

What did you use to test for spark at the coil? That is a high voltage circuit and will most likely fry a 12v tester. I think the 4.3l puts out at least 15,000v to the cylinders...

Regardless, what year? What engine?

 

Oops, guess I shoulda put that info in! Its a 98 4WD 4 door. 4.3 vortec. I did test it at the coil, then tested at the pigtail that plugs into the coil.

 

do you got power to the dash radio ?
did the dash go out when i shut off

 

Have radio power. One thing tho, the tach quit workin about 3 weeks ago, and she said the speedo went to zero as soon as it died, but truck was still coasting. Don't know if that's noteworthy or not.

 

well when the truck shut down did you loose power do your dash and radio?

 

I have power to the dash and radio. However, gas gauge is on empty like it's not working (I know there's at least a quarter tank) and the gear indicator is lit up, but doesn't reflect what gear it's in. so that part doesn't work. I'm starting to think along the lines of a bad ground somewhere. I'm gonna look around this site, but where can I find the location of all grounding points?

 

Well, have confirmed there's no spark, and def not hearing the fuel pump. I'm stumped. Guess I'll sell it for the junk it is. Too many probs since I bought it. Thing has been a constant headache. Meanwhile my 2 hondas keep purrin along.

 

There is probably one simple thing wrong with it! I hate to see someone junk a vehicle because of a broken wire. Find the appropriate wiring diagram and grab a multimeter. Could be as simple as a loose ground, loose power wire or bad ignition switch ect.

FYI - EDI creates much much more than 15,000 volts. I know gm's distributorless can get up to 100,000 volts. (But that is a waste spark system)

Good luck!