Need help with HEI. 12v wire only giving 10v when running. Drops out at higher RPMs

[MadMax_636]

So, This is a bit of a update on the HEI conversion.

For some reason my hot wire with KEY ON shows 12v. Once its running, Its only showing the HEI getting 10v.
I tried hooking up right to a 12v wire that supplies right from the battery (I wired up a relay that controls a electric fan, lights, and so on) and it runs the engine. The coil then gets hot and shuts off. I believe its "Over voltage protection" but Im not sure.

I need help with getting this fixed because it makes the truck undrive-able.

 

[franklin2]

The HEI is rated for full voltage. It should not get hot and shut off. What brand HEI module are you using? Do you have another one to try? One off any old chevy will work. Originally it's mounted in the distributor on the chevy.

Or you could go to plan B and run a duraspark II ignition box. It does require the resistor, but the resistor should be in your harness unless you wanted to run a external one.

 

[MadMax_636]

The HEI is rated for full voltage. It should not get hot and shut off. What brand HEI module are you using? Do you have another one to try? One off any old chevy will work. Originally it's mounted in the distributor on the chevy.

Or you could go to plan B and run a duraspark II ignition box. It does require the resistor, but the resistor should be in your harness unless you wanted to run a external one.

I bought one off Rockauto. Ill be buying a brand new one after payday. Hopefully itll cure it.

what value of resister should I get for a external one?

 

[MadMax_636]

The HEI is rated for full voltage. It should not get hot and shut off. What brand HEI module are you using? Do you have another one to try? One off any old chevy will work. Originally it's mounted in the distributor on the chevy.

Or you could go to plan B and run a duraspark II ignition box. It does require the resistor, but the resistor should be in your harness unless you wanted to run a external one.

This is the one I have.

More Information for ULTRA-POWER LX301

 

[franklin2]

I bought one off Rockauto. Ill be buying a brand new one after payday. Hopefully itll cure it.

what value of resister should I get for a external one?

You only need a resistor if you are going to run a duraspark II module. The HEI runs on full voltage, no resistor in the circuit.

 

[MadMax_636]

You only need a resistor if you are going to run a duraspark II module. The HEI runs on full voltage, no resistor in the circuit.

Ok cool. Well, Once I get my new HEI ill wire it up to direct from the battery power. I wired a relay that switches on with the ignition.

I guess my specific HEI is faulty.

 

[franklin2]

The relay should cure your 10 volt problem. 10 volts will activate the relay if that is still the voltage you have.

 

[MadMax_636]

The relay should cure your 10 volt problem. 10 volts will activate the relay if that is still the voltage you have.

Yeah, The current HEI over heats and shuts off if I give it full voltage. I even put a bigger heatsink thinking itd help... it didnt. I wired up a whole new power delivery system.

I installed a power block thats powered right off the battery, ground thats right off the battery, and the relay switched from the 12v the ignition is on right now. I have a lot more space for other projects too. I mainly did it so I could wire up a electric fan since when I replaced my water pump and I had to cut the damn thing off. Seized tight. Fan blades were cracked all to hell too.

 

[MadMax_636]

The relay should cure your 10 volt problem. 10 volts will activate the relay if that is still the voltage you have.

UPDATE:

I had the HEI fail on my way to work... Was able to let it cool down and get it running enough to pull into work (Died at the U turn I take to get into work.) I ordered a new part through the parts department at the dealership I work at. The new HEI worked perfectly! Now getting 11v. So Im sure this new one will work on full voltage.

I believe the old one was faulty out of the box and only worked at the 10v that it was getting. Im gonna test the resistance from "B" to all the other 3 pins.

 

[MadMax_636]

I am hearing coil noise in my radio. With the aux. I dont have a antenna or anything hooked up to my radio.

The original capacitor is hooked up.

 

[franklin2]

That's noise on the 12v line, since you are not using the radio, just the aux. You can try a capacitor on the alternator line. You could also take the alternator in, I think their machine will tell you if one of the diodes is bad and there is some A/C on the DC output of the alternator.

Or, what would definitely fix the noise is one of these. You install it on the power wire going to the radio.

Amazon.com: Install Bay IBNF10 Noise Filter10 AMP Each : Electronics

Buy Install Bay IBNF10 Noise Filter10 AMP Each: Noise Filters - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[SenorNoob]

That's cool. I've never seen those bay.