2 problems? (1994 ford escort) heating/ac related


jruss00
04-10-2010, 11:00 PM
I'm having some problems here, I replaced my thermostat today and it didn't fix my first problem. My needle for the C/H on the gauges barely moves and I mean barely, I noticed that my car hogs up alot of gas and I read online that this could be causing it so I wanted to fix that for sure...

Any advice on that?

Also, my heater and air conditioner barely works, it barely blows any heat out and i switched that thermostat out today hoping that would fix it but I was wrong. I can turn my switch up to the 3rd setting but if I turn it onto the 4th (highest setting) it completly turns off? I can't figure out what it is causing it and would like to get this fixed lol, I don't think my hoses are bad they seem alright.

When i put it on heat all the way to 3 it will blow heat but takes a while to get hot and barely blows any out, it doesnt get to it's maximum hottest I know that for a fact cause it's barely warm at all.

A/C is like that too.

There's a switch that powers the heater/ac under the glove box its like a bluish switch and i think the wiring is a little messed up cause sometimes you have to jiggle it to work..

any suggestions and pricing on this and can anybody provide me with links?

Intuit
04-12-2010, 11:19 PM
Few different issues are going on.

1) http://www.automotiveforums.com/vbulletin/showthread.php?t=970041

Corroded contacts on the blower motor wire harness that need to be replaced.

2) Thermostat bypass valve may be open. It is apart of the thermostat housing, called a "water outlet" in parts stores.

3) Thermostat itself may be deteriorating, if it's still the original equipment. Something to be aware of, is that the thermostat housing bolts, often break off (studs being lodged in the head) while attempting to remove them.

4) UNRELATED: While servicing the thermostat, go ahead and retorque the mounting nuts for the exhaust and intake manifolds. If you (or a passenger) mentions that they smell coolant, yet there are no external leaks, have a compression test run on the engine.

jruss00
04-13-2010, 12:47 PM
Few different issues are going on.

1) http://www.automotiveforums.com/vbulletin/showthread.php?t=970041

Corroded contacts on the blower motor wire harness that need to be replaced.

2) Thermostat bypass valve may be open. It is apart of the thermostat housing, called a "water outlet" in parts stores.

3) Thermostat itself may be deteriorating, if it's still the original equipment. Something to be aware of, is that the thermostat housing bolts, often break off (studs being lodged in the head) while attempting to remove them.

4) UNRELATED: While servicing the thermostat, go ahead and retorque the mounting nuts for the exhaust and intake manifolds. If you (or a passenger) mentions that they smell coolant, yet there are no external leaks, have a compression test run on the engine.

I already changed the thermostat, when i took out the other one it was still good so i just put a new one in anyways. what is that wire called so I can purchase it this week and switch it out? I'm going to buy it from advance auto parts. There's no burning smell or anything either..

mightymoose_22
04-13-2010, 03:53 PM
Your engine is overcooling. It is likely just as you thought- water is getting around the thermostat. However it is obviously not the thermostat causing the problem. As mentioned above, the housing that the thermostat sits in, the "water outlet", has a plastic bypass valve inside of it that has likely melted and is allowing water around the thermostat which essentially keeps it open.
With the symptoms you describe, in all likelihood you need to change that housing. It is the exact same job as changing out the thermostat... same parts come off.

Intuit
04-13-2010, 04:11 PM
If you wiggle the harness the motor should work on high again... for a short time. Eventually it will get bad enough that it'll burn-up the plastic harness.

No "wire" unfortunately. You can check with the dealership to see if maybe they sell some kind of replacement wire harness kit for the blower motor. It's a common issue; wouldn't surprise me if they do. Otherwise you'll just have to record the wiring as-is, then replace each of the connectors one-by-one. (<--what I did) Parts stores carry subtable gold-plated connectors as replacements. (actually meant for audio equipment) Wire harnesses in the junkyards (I discovered) will all be in worse or same condition; or already cannibalized. As a warning, the wiring for the harness is *JUST* long enough. Cut only the very ends off and you *might* have enough left to attach the new connectors and still reach the resistor. Otherwise you'll have to solder (not crimp!) on a small extension for the wiring. Most time-consuming part is just getting the old connectors out of the plastic wire harness without damaging it. Backups for the plastic harness can be obtained from any junkyard. Some plastics may be brittle. Do not attempt to connect to the resistor without the prophylactic plastic harness casing. This prevents shorting.

jruss00
04-13-2010, 10:13 PM
so the thermostat being stuck open would cause the gauge not to work? It's moving slightly but not alot. And what is this all called to fix this thermostat issue? Thermostat housing?


Also, I jiggled the harness your talking about and it sparks kinda and even when i jiggle it, it still won't work on the highest level, i can only get it to go to the 3rd speed setting :(

i get a little bit of heat but not alot, and no a/c just like wind but a tad bit cooler.

Intuit
04-13-2010, 11:23 PM
You gauge says it's cold. You're not getting any heat.

Possibility
A) Your gauge is broken AND your heater core is clogged.

Possibility
B) Your engine is over-cooling.

It's that simple. Fix known problem 'B' then worry about the less likely 'A'.


===========

Re Blower:

Take out the two 10mm bolts and inspect the resistor. It may be severely corroded to the point that it needs to be replaced along with the contacts on the wire harness. The resistor you almost have to get new. In this specific case, junkyard parts are generally just that... junk. If high still doesn't work then test to see if you're getting 12v at the largest gauge resistor element by back-probing the wire harness while plugged-in. (I believe that is high but not sure.) If you're not getting power then it's likely that a fault has developed somewhere else in the system... either the wiring or/and the switch itself. Order of progression however is to take care of the known issues first. Otherwise you could fix the switch only to leave the underlying cause in place to do damage all over again.

Intuit
04-13-2010, 11:28 PM
no a/c just like wind but a tad bit cooler
Totally separate issue. Does the compressor just keep cycling on/off ? If so, most likely needs refrigerant added. Once added, compressor should stay engaged a lot longer between cycles; and your air become a lot cooler. Be sure to add an oil charge along with that refrigerant. If you don't or rarely use defrost on the slider, you should run the compressor occasionally over the cooler months to help keep it lubricated.

jruss00
04-14-2010, 11:29 AM
You gauge says it's cold. You're not getting any heat.

Possibility
A) Your gauge is broken AND your heater core is clogged.

Possibility
B) Your engine is over-cooling.

It's that simple. Fix known problem 'B' then worry about the less likely 'A'.


===========

Re Blower:

Take out the two 10mm bolts and inspect the resistor. It may be severely corroded to the point that it needs to be replaced along with the contacts on the wire harness. The resistor you almost have to get new. In this specific case, junkyard parts are generally just that... junk. If high still doesn't work then test to see if you're getting 12v at the largest gauge resistor element by back-probing the wire harness while plugged-in. (I believe that is high but not sure.) If you're not getting power then it's likely that a fault has developed somewhere else in the system... either the wiring or/and the switch itself. Order of progression however is to take care of the known issues first. Otherwise you could fix the switch only to leave the underlying cause in place to do damage all over again.


how would i fix problem b? I'm not real good at cars but my dad use to have a shop so he helps me out some. We can't figure it out tho. Also, are you familiar with where the heater core is?

Intuit
04-14-2010, 01:43 PM
Problem B Solution --

Your engine is overcooling. It is likely just as you thought- water is getting around the thermostat. However it is obviously not the thermostat causing the problem. As mentioned above, the housing that the thermostat sits in, the "water outlet", has a plastic bypass valve inside of it that has likely melted and is allowing water around the thermostat which essentially keeps it open.
With the symptoms you describe, in all likelihood you need to change that housing. It is the exact same job as changing out the thermostat... same parts come off.

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