I just bought a 2000 ford ranger with 205000 miles. It has the 3.0 v6 and runs pretty well up and down the highway. Anyways after 3 days of highway driving I noticed my heater just quit working. It blows cold air. I also noticed what appears to be a leak on the front passenger side of the truck. Im not a mechanical wizz but after reading some stuff on here I found either a timing chain gasket or a coolant leak. Would either of these cause the heater to immediately quit working?

 

Sounds like a coolant leak in the heater core. Check your radiator when it's cold.

 

Welcome to the forum

When engine is COLD remove radiator cap, check coolant level, should be at the very top no air in radiator
If it's not at the top then add some coolant or water, either is fine
The Heater in the cab is at same level as top of radiator so low coolant level can cause NO HOT COOLANT in the heater, so no heat in cab

Start engine and let it warm up, have heat control in cab on Defrost

After engine is warmed up, 3 min or so, and idling, open the hood
There are 2 heater hoses that run from the front of the engine to the Firewall(cab) on passenger side of engine bay
Feel both hoses at the firewall, both should now be warm/hot

If so then go to cab and turn TEMP **** to HOT, and then back to COLD, a few times, see if temp of the air coming out of Defrost vents change temp at all
If not then your Blend Door Actuator has failed in COLD position
Not an uncommon issue in all Fords of these years

Google: Ford Ranger Blend Door Actuator
Lots of info on fixing these

If temp changes, so you now have heat in the cab then you will need to locate the Coolant Leak, but keep coolant topped up until you do


Just as a heads up when you see water under the passenger side of cab just behind front tire on that side
Its normal if you have Air Conditioning
AC is on all the time, not just when you select AC on the dash controls, just FYI
AC dries the air before it goes into the cab vents, this helps with Defrost but also prevents Musty smells in the cab in winter months
As it dries the air(removes the water) the water drips out from a tube in the firewall on passenger side
Happens on ALL vehicles equipped with AC, not a Ford thing, but you may have never noticed it