88 Bronco 2 No spark

[RobbieD]

EDIT: just turned the heat off and now it does not miss or hesitate, what gives?

The heater blower is a current hog.

There should be a ground wire from the battery negative clamp terminal to the inner fender. Make sure that yours is there, that it's connected and not rotted. For testing, you can also use a single jumper cable to connect the negative battery post to clean metal on the body someplace; if the problem goes away with cable connected, then your body's not grounded properly.

The blower can also get wire rot at the blower motor connector and at the resistor plug connector, which can increase the already high draw when the blower's on.

And I think that there's also a ground strap from the engine block to the firewall, which usually has been disconnected over the years.

 

[Mhfco6]

The heater blower is a current hog.

There should be a ground wire from the battery negative clamp terminal to the inner fender. Make sure that yours is there, that it's connected and not rotted. For testing, you can also use a single jumper cable to connect the negative battery post to clean metal on the body someplace; if the problem goes away with cable connected, then your body's not grounded properly.

The blower can also get wire rot at the blower motor connector and at the resistor plug connector, which can increase the already high draw when the blower's on.

And I think that there's also a ground strap from the engine block to the firewall, which usually has been disconnected over the years.

Thanks guys I will check the grounds out. Must be intermittent, it rough regardless of blower on/off after playing some more. I ran 10 gallons of distilled water through my coolant system with stat removed and drained about 10 times. It’s not gritty anymore but still brown looking, but consistent color through the last 3 gallons. My heater core is defiantly leaking/dripping now and loosing coolant. I’m going to replace it in hopes the over heating will stop. The over heat and rough engine should be my last two hurdles.

 

[Mhfco6]

Replaced heater core and topped her off this evening then ran the truck for about an hour. Temp gauge never even made it half way up. All the grounds seem good except for normal greenish corrosion near the ends. I’m going to replace some of the 4ga cables. I did notice a ground strap from the firewall to the hood all chewed up but that’s it.

 

[franklin2]

I did notice a ground strap from the firewall to the hood all chewed up but that’s it.

That's an important one. Also look over at the battery negative terminal. Usually the large ground wire clamp has a smaller wire coming out of it too. It usually goes to a single wire plug and then disappears into the harness. This is the ground for the computer. It lives near the battery so it has a hard life. Make sure it's in good shape. If you find it, you can unplug it, when I do that usually the engine will not fire at all with it disconnected, it's that important.