80 Series General Tech and Classifieds (6 Viewers)

[JTU]

Looks like I’m headed to the store in the morning for some acid. I really don’t want to rip the whole dash out for a heater core replacement.

 

[jynx]

Did the heat stop working the same time the rear was bypassed? Just curious if the bypass may have got both.

 

[JTU]

@jynx it stopped working sometime last summer. It used to work fine while bypassed. Mine is a LX so it has the auto climate controls.

 

[JTU]

@Bossman just check. Hoses on both side of the control valve are hot to the touch

 

[jynx]

Are you sure the valve is operating? Just wondering if the electric control may not be telling the valve to open. I have heard of the controls going out.

If everything else is working, sounds like it may be in the core.

 

[dnp]

Careful with a core "cleaning" with something caustic. It's 20+ years old now, and if it's bad enough to get clogged, it may just end up causing it to leak....

 

[JTU]

I’m going to try some CLR first before going with muradic acid

 

[Bossman]

You said you bypassed the control valve as a diagnostic step right? No chance the valve is stuck? I'd make darn sure before running muriatic acid through it. I do have a FZJ80 valve you can borrow to check it out first if you want to do that.

 

[JTU]

Heater core backflush looks like it’s pumping out chocolate milk

 

[JTU]

Heater core back flush didn’t do sh*t. I used a 50/50 ratio of muratic acid/distilled water. Let it sit for 15 minutes and then flushed it out.

Going to try again tomorrow with a stronger 75/25 mix of muradic acid/water.

 

[jynx]

Uhh, if the water is moving thru the core, would that not suggest that it is flowing? And if it is moving, then wouldn't that suggest that the core may not be the problem?

Did you rule out the control valve?

 

[heckler]

Calling all 80 series whisperer’s.

Cold weather season is approaching on MS and the heat still doesn’t work on my 80. I have replaced the thermostat with a new OEM, flushed the entire system multiple times, burped it as best I could, replaced the fan clutch with the OEM blue hub one and still no heat. The adjustment on the heater control valve is correct. Even bypasses it and no change. Engine hovers around 188 says the scan gauge.

Any help would be appreciated. Don’t want to freeze on the winter camping trips this year.

You might want to check into the climate control computer, it is above your right foot (a white box). It can get moisture in it and cause the heater to stop working.

 

[JTU]

Is the auto climate control ever an issue on 80 series? Do they ever go out? I’m starting to think that it’s somerhing else besides he heater core or control valve.

 

[heckler]

Yeah I have had mine go out and the heater did not work. Some how that box gets moisture in it, some say it is a leaky windshield, but I never had water anywhere else.

 

[heckler]

I will try to find a link in the 80 section so you know what box I am talking about.

 

[heckler]

SOLVED !! A/C electrical problem

Here is one thread that talks about what I mentioned

 

[JTU]

Wonder if you could swap in a climate control box from a 1996 that doesn’t have the auto controls.

 

[offr0adlim0]

Wonder if you could swap in a climate control box from a 1996 that doesn’t have the auto controls.

Yes

 

[heckler]

Not sure about that, but worth a try if you have access to one.

 

[heckler]

Also if anyone is looking for a M10000 winch for their ARB
Winch