Tach wire stalls Blazer
 

Ok so I've gotten my fuel hose and line issue all sorted out! :icon_banana: But now another (older) problem is still baffling me. A while back I put a Pertronix Electric Ignition into the Blazer (1971 w/350) and when the tach wire is hooked back up to the coil it kills the engine. Unhooked it runs just fine but the second that wire touches the coil it's lights out. I have no idea what could cause this and it's annoying since I know that having a factory tach in a first gen Blazer is semi-rare and mine is inop :icon_cry:

You are connecting the tach wire to the ground side of the coil right? Connecting it to the positive side will short out the circuit.

CLICK HERE for an article with a good diagram courtesy of HotRod.com.

Yes we hooked it back up per the instructions included with the ignition. When that didn't work we tried the positive side and it did the same thing.

if its a hei ignition set up it will say "tach" where you plug it into. if you are plugging it into the correct place and its killing the engine it is probably grounding out somewhere. i used to run a kill switch like that when i was way younger. turned out to be a stupid way to do it as it ended up shorting out my ignition module one day when i forgot to flip the switch before starting the truck. so maybe trace the wires make sure its nor frayed or smashed somewhere and grounding out

I will give it a try. There's a lot of wires under that hood ha ha but it will be worth it to hopefully get it working again.

How'd that turn out?

Considering you bumped a thread having it's most recent reply 8+ years ago, I'm going to go out on a limb and say your chances of getting an answer are slim... Please be aware of the age of the threads you are replying to when asking these simple questions and not adding anything to the thread in question. While it would be nice if the OP had given resolution, asking for said resolution years later is likely not to happen.

I'm starting to see why there are so many one post and done new members on this site. Cheers

:confused:

Wow, I can't believe I never responded to this thread! I'm sorry for my poor etiquette! I tried one of the solutions above, it wound up being the tach wire that was frayed and grounding out. Once I covered that up, it worked great!