I got a 1985 D-100 pickup and would like to no where the ballast resistor is located. Looked on the fire wall and have found nothing or nothing that looks like one.

You probably do not have one---most likely a lean-burn ignition or Spark Control Computer (SCC). Lean burn will have a "computer" on the aircleaner housing. SCC would be behind your battery up under the driver front fender. Both models have a distributor with two magnetic pickups (2 sets of wires coming from the dist) and no Ballast Resistor, IIRC.

-S/6

_________________
The "Silver Bullet"
87 Ram D150

I'm new to Mopar products, know about GM products but what is the difference between lean burn and SCC. My truck has nothing on the air breather. It does have a dual pickup distributor and its new. Keep fighting that miss or rough idle. Bought rebuilt carb from Advance Auto and after reading some topics on this forum my problem could that carb.

Have you checked your valve lash recently? That's a common cause for a rough idle/miss. They should be close to .010 intake, .020 exhaust. -zorg

_________________

Zorg...starting in 1981 model year slants the lifters are hydraulic, there is no lash to be set on these motors...

Though he could have a peice of carbon lodged on top of a lifter, or a bad seal that lets some oil into the chamber via the valve stem, or just burning oil and fouling the plugs,...

If the plugs are fouled, and the carb is set right, and you aren't ready for rebuild, you might need a hotter plug to 'burn off' the soot...

-D.Idiot