Tried to hook up 12 volt to HEI
 

Today I attempted to hook up a 12volt wire to my HEI. I ran a 12 gauge wire to the fuse box hooked the wire to the middle lower accessory switched plug that says IGN beside it. I checked the plug to make sure that the wire is switched on with ignition. Now that I think about it the marking must be for the fuse!? I then attempted to start the car. First crank engine turns over, car been sitting so maybe no gas in carb, I then pump the gas and crank it. Now sounds like no spark, then big puff of smoke from under the hood! Bad day already (see members helping members "97 Yukon help"), just put the yellow wire back the batt connector on the HEI, drove to get some gas and came in the house.

Could I have did any damage? Why did the car not start?

Thanks

Don't know what you're working on. You need to see if the ignition terminal is hot with the switch in crank position. If it doesn't, you only had fire when letting on and off the switch from crank. This would make the coil fire once everytime power was cut on and off. That could've made it backfire through the carb and blow smoke.

Chances are nothing is hurt. Just need a non fused wire that's hot in both crank and run positions of the switch.

Depending on what you've got, it could take a jumper from IGN 1 to IGN 2 on the switch, or a wire from the starter solenoid R terminal up to coil + terminal (BATT) for cranking.

Need more details
Check it out and post back

Sounds like Quick hit the nail on the head. Its vital that you have 12V in start and run positions...usually the later model fuseblocks have terminals you can use for that purpose...my '72 GP did anyway. Checked it with a meter and hooked up a nice 10 ga wire and I was good to go. I agree with Quick as far as nothing was probobly hurt. I love HEI's.

I'm sorry, the car is a 69 GTO.......yes I just checked the terminal to make sure it had power with the key turned onto the on position.....

You would need power to that terminal when you hold it over to the crank position.....JB.

"Depending on what you've got, it could take a jumper from IGN 1 to IGN 2 on the switch, or a wire from the starter solenoid R terminal up to coil + terminal (BATT) for cranking."


Does anyone have a picture of IGN 1, IGN 2 on the switch for a 69 GTO? I will attempt to find it later tonight........thanks

If you have a T400, run the wire to where that fuse is. I bought these copper clip that fits around the round fuse and has a spade to put the HEI wire onto.

Wire colors is all you need.
 

HEI hooked to Ignition switch with IGN 1 and IGN 2 jumped together, will make this work like factory. IGN 1 is the black with pink stripe wire and IGN 2 is the yellow wire plugged in the ignition switch, under the dash, on top of the column.
The section of resistance wire is in the harness right before the firewall bulkhead connector. So I like tieing the HEI wire in close to the switch. Spliced to black/pink, yellow, or tie all three together.

Ignition terminal in fuse box doesn't keep 12 volts on it. It gets power through a pink wire from the same place as IGN 1. With IGN 1 and IGN 2 spliced together, ignition terminal in fuse box does keep power on it. Just one problem, It's feedback through the resistance wire, so you don't get full voltage.

That's the reason for hooking the HEI wire in close to or at the ignition switch.

12 volts?
 

I tried to check the voltage out put for the battery feed to the distributor, I had the key turned forward and used an multimeter to try to determaine the output. It read 12.07 volts. Is this reading correct?

You have to have 12V in the run and Crank Positions.

So the reading I got was just in the crank position?

Mook, please call M&H fabricators, they know what to do, i sent my wiring harness ti them, illiminated the voltage regulator, and went with one built into my alt. redid everything for a really low price i thought. Hope this thought helps you out. P.S. they also will explain why to never go to the fuse box like your doing!!

Start with the Key Off
Turn the Key to ON aka Run Position...check voltage..should be 12V
Turn Key Farther to The Crank or Start Position and Hold...you may need to use alligator clips on the ends of the meter probes so you can have use of your hands...should have 12V ...You need to have 12V in On AND Crank Positions.

I'll check them out......I will never go though the fuse box again!! I just wanted to make sure that I don't have the required 12volts before I decide which way to hook it up.

Ok .......I ran a 12 gauge wire from the batt terminal at the distributor, the the key forward the multimeter read over 12.07 or so volts, with the car running it read 14.25 or so volts...is this good or bad?

Mook Im certainly no expert and Ive converted quite a few of my Pontiacs to HEI, never having an issue and I'm only going from memory on this point...that it isnt good for the module in the HEI to have more than 12 Volts run through it for any length of time...I believe I read that on here somewhere actually. I do not know the specs on the module or how much voltage it can handle, I'm sure someone who knows better can chime in on that point. Sorry I cant be more help; Id really hate to see you fry the module though...Again, I'm only going by memory so I may indeed be mistaken.

No problem....I really appreciate your and all my PY family help!

HEI doesn't have or use any kind of resistance wire. So running system voltage is absolutely normal and wont hurt a thing. Battery volts with key on engine off and alternator output volts with engine running. Same thing every thing else on the car gets.

Sounds to me like you're good to go.

Thanks for straightening me out Quick...