gootz4u

Hello, here I am once again asking for information. I have a 1992 Jeep Cherokee. I love this jeep ha. Well its cold and I am trying to fix my heater. I have been fixing things which I read that could be the reason why my heater is not working. I have.... flushed my heater core, water came out clear. When engine is running, only one heater hose was hot and the other was cold. I bypassed the heater control valve but I don't feel like the hoses feel hot enough. I changed my thermostat to 190 degree and still not hot. It sounds the like the blend door is working. I checked for vacuum leaks and seems ok. I made a home made vacuum reservoir out of 2 in PVC pipe but still nothing. What else could I check?

PatHenry

Did you flush the heater core both ways?

gootz4u

Thanks for replying PatHenry, no I only flushed it going reverse. Should I have done it both ways?

wauto

Just did mine heater core flush last nite. Both directions, twice. She is making heat again. I do this every two years. My xj has 254k on it now, so I expect a little maintenance.

gootz4u

Thank You wauto, I will re flush the heater core.

PatHenry

I was going to say - YES - definitely flush it both ways and let us know the results.

gootz4u

Ok, I will PatHenry, thanks for replying. I will be getting back the results by tomorrow night. Hopefully this will get some heat coming out.

gootz4u

Ok so I tried to flush the heater core both ways and I think my heater core is bad. I hadn't driven the jeep this past week. When I flushed it out, the passenger side carpet floor was completely wet. It was not wet until I started to flush it out. I think its time for a new heater core. What do ya think?

PatHenry

Almost certainly a hole in the heater core.
There was a thread a while back where the hose was bad, but it was on the engine compartment side IIRC.

My sympathy to you, it's a beast of a job to replace. Take your time and take a lot of pictures as you go for reference. There are write-ups for this.
You could always do a heater core bypass if you can live without heat and/or as a temporary fix until you have a free weekend to do the core.

gootz4u

Hello, so, this past weekend, I finally took on the job to replace the heater core. I found a few feeds that showed step by step, but it was not a difficult job. It did, however, took a long time. It took me 12 hrs to compete. I finally have heat, BUT..... my blower is not working now after I put everything back together and noticed the blower not working, I looked at the fuse, under the dash, it was a little burnt so I replaced it. Still nothing. There is no current going to the blower so I backtracked. I noticed the relay was really old so I just replaced it. There is not current at those wires either. The wire is a dark green if Im correct. So far, I have current at the fuse under the hood, at the fuse under that dash. But somewhere, there is no current from the fuse under the dash, to the relay. Does anyone happen to have some info on how to fix this? I know the blower is good because I just replaced it less than a year ago. Before I took the dash apart, the blower was working, but now, it is not. I don't recall disconnecting any wires at the heater core box. Does any one have any suggestions please?

gootz4u

gootz4u

gootz4u

steelybill

What about the heater fan switch ?? I went through this a few years ago & ended up replacing a bunch of stuff that got smoked from over-heating... I bought the new blower switch from a place called Parts Marvel. The p/n on the receipt is unreadable..sorry. You can get some parts there as you find out what it may need..

Bill

steelybill

There are blower motor resistors also, for the low & medium speeds. The service manual isn't very good at this. I just found the scorched parts & replaced them !