1989 Ford Ranger were is the pcm relay located

ECA is used on this vehicle and is behind right kick panel. ECA relay is on right front fender panel, on relay block.

[quote:24340ddca9="bluelightnin6"]ECA is used on this vehicle and is behind right kick panel. ECA relay is on right front fender panel, on relay block.[/quote:24340ddca9] is it near the power distribution box

is it located near the power distribution box

The ECM will be in 1 of 3 places: It will be behind the kick panel in the driver's foot well, in the firewall under the brake booster or on the firewall in the pasenger side footwell just above the trans hump.

On the "Foreign car" Fords, the ECM is behind the kick panel in the passenger side footwell. I don't think the Mazda B-truck and the Ranger were close enough in 1989 for the Ranger to be a "Foreign car" Ford and the ECM location was identical for the Explorer, Aerostar and Ranger starting in 1990, so I'm betting you'll find the ECM on the firewall in the passenger side footwell. You'll know you have the ECM when you find the 104-pin connector held on with a 10mm bolt.

Hope that helps!

can the ecm cause one of the coil packs not to put out a spark

yes it's possible because the ECM does send signals to the coil packs

will the ecm be a big round thing with a bolt in the middle of it holding it on

i don't see any thing under the hood that looks like that but i do have some thing that looks like that under the dash on the drivers side that looks like that could that be it

shouldn't be underhood, should be in cab of truck , you have found it most likely. is the electrical connector to it pretty wide? should have around 103 little pins .