Electrical AC issue / intermittent electrical issues - 1997 FZJ80

Joined
Oct 25, 2021
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439
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WA/OR
Because my original thread was initially about speakers and I was asked about symptoms of an electrical issue I noted in the post, I'm moving my response to get some additional insight and advice.


*** *** *** ***

I redid the entire cooling system at the end of August, replacing the radiator, hoses, fan clutch, water pump, thermostat, heater control valve, engine flush, etc., and for a few days after, the AC worked without any issue. Then it started taking longer to kick in, but it would...then it would begin to slowly get warmer (AC, not engine) until no more cold air was blowing. This continued for a few days until it just wouldn't blow cold at all. So, thinking the refrigerant was too low, I picked up a can of DIY refrigerant to add. I placed the hose on the correct tube and the dial told me it was FULL, so, I didn't add any and decided to call the Land Cruiser specific shop I go to to check it because it seemed like the AC clutch wasn't engaging.

Fast forward a month (that's when they could get me in), they evacuated the refrigerant and checked for water residue...nothing out of place. The compressor was working fine, no leaks and no breaks in the seals. Everything indicated that it should be working...they even tripped the clutch to go and verified there are no bubbles in the viewing window(?)

While waiting I was texting a buddy of mine who assisted with the cooling system update and he remembered there was "an electrical plug" on the side of the block that was not connected so he "plugged it back in" to the "only available plug near it".

I sighed at this point and told the tech about hat i was told.
But in telling this to the tech, because the AC had worked for a handful of days after, this plug being the problem was ruled out.

The shop has replaced the ac "switch" under the hood (near the battery - for reference, I have a '97 with a single battery) and pulled a bunch of unneeded wiring out that the PO had installed with a janky stereo system. We found a relay that was a little more worn than it should have been but it didn't seem to be the problem.

The shop believes it might be a different relay of some kind (if I am understanding correctly), but the day ended so I had to reschedule another time (last Friday) to come in with another tech who had a little more experience with this type of issue. When I came back, we went over everything to give him the run down of all the symptoms and what the previous appointment entailed - everything is technically working as it should but there seems to be an electrical signal not making it's way to tell it to "get cold" - the heat works fine though...he turned the AC on at the control panel in the cab and let it run for a while, I assume to see if there was a power draw someplace...and then something blew out - one of the most horrible electrical burning smells then followed...

If I'm understanding correctly, the shop thinks there might be something going to ground, a surge, OR the AC control panel in the cab just decided to go out after 25 years, thus requiring the dash to come apart...which I'm OK with, so long as the issue gets resolved, PLUS it give me a chance to get the Center Diff Lock button installed AND update the head unit - even if it just sits there for the time being. I haven't had a stereo running anyways for quite a while because of this issue.

I've sourced a new/used working panel from @Alex79 and just waiting on its arrival to the shop.

In reading multiple MUD posts, I found this thread: 1993 FZJ80 - AC electrical issue & not working (Compressor in good condition & system not leaking) but there is a lot of electrical notations that I'm unfamiliar with. I also found another thread about intermittent AC issues, and a post about the Engine Temp AC cut-off switch (relating to the engine hitting 227 degrees F and cutting the AC) but I can't find that post for some reason. If I remember correctly, this switch tells the computer that the engine is too hot (227 degrees F) and to cut the AC...so I thought MAYBE that switch was bad and it just thinks the engine is hot when my ODB2 reader tells me I'm sitting pretty at 179 F at 65 mph sustained for 60+ min and around 181 F in stop and go traffic.


So, that's that.
I'm at a loss...I'm going back to the shop as soon as the ordered parts arrive, either this Friday or next. Right now, the fuse for the AC is pulled. the Cruiser is driveable, but she's sitting since she's not my DD.

The shop also thinks this might also be part and parcel of my OTHER electrical issues which could stem from the PO and their janky install of a stereo that suspiciously looks like a big box store didn't know what they were doing with a Land Cruiser, or, a "friend" who "knows" how to install a stereo.:

  • Sunroof not opening (not even a sound of an attempt when depressing the button)
  • Cigarette port not working
  • Light in ashtray not working
  • All windows not working
  • Clock not working
  • Stereo not working
  • Rear dome light not working (but middle and front map light DO work)
  • Antenna not working
  • Right side instrument panel lights not working (But left side of panel lights up)
  • Side mirror controls do not work
  • Green ring around ignition stays on ALL THE TIME and I know it shouldn't

And yes, all the fuses have been checked - nothing wrong there - none of them have blown.

  • Door locks work - except the rear hatch (I was unsure if it was electrical but have since been informed the rear lock IS electric)
  • Door lights work
  • Electrical seats move (forward, up, down, reclining, and lumbar, but won't move BACKWARDS - on both, but that could be a bad worm drive)
  • All gauges work - verified against ODB2 reader
  • And until recently, AC worked (Heater works fine, so does the defroster - verified the Heater Control Valve was installed correctly and not backwards, hahaha)


I go to a Land Cruiser specific shop so I have complete faith in them...I'm just frustrated at the previous owner more than anything else. Had I known what he did when I bought it, I would have given less than the $2,300 we agreed on to offset the electrical chasing, haha!


Thanks in advance!
 
Joined
Jan 5, 2017
Messages
4,172
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Charlotte, NC & Alexandria, VA
Damn!

You have your work cut out for you. At this point, if it was me, I'd get an EWD, start at the battery and work my way to the ends of the engine harness. After you get through there, and only then, start on the A/C circuit.

There is a temp switch in the DS side of the head, which cuts off the A/C at high engine temps. It's called an A/C cutoff switch, for some reason. The sensor is still available, but the engine harness connector is not. You'll have to scavenge one from any Toyota of the last century; they all have them in the engine harness. I doubt that's the problem though, especially since you seemed to have let the smoke out somewhere else.

FWIW, $2300 isn't a bad deal for a project truck. Good luck.
 
Joined
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Messages
439
Location
WA/OR
Damn!

You have your work cut out for you. At this point, if it was me, I'd get an EWD, start at the battery and work my way to the ends of the engine harness. After you get through there, and only then, start on the A/C circuit.

There is a temp switch in the DS side of the head, which cuts off the A/C at high engine temps. It's called an A/C cutoff switch, for some reason. The sensor is still available, but the engine harness connector is not. You'll have to scavenge one from any Toyota of the last century; they all have them in the engine harness. I doubt that's the problem though, especially since you seemed to have let the smoke out somewhere else.

FWIW, $2300 isn't a bad deal for a project truck. Good luck.
Thanks for the insight!

Oh, she runs like a top. Multiple LC shops have mentioned how good the engine performs, and after my cooling update, it runs even better. New tires were the first thing in May because they were dangerously bad, then the cooling system along with belts and an oil change. My next job is the Ignition (cap, rotor, plugs, wires). I bought her seven years ago but I'm just now in a position to where I can do the things I want...but, baselining her is my priority before adding armor or a lift ;).

I did find out that the PHH was replaced "about 20-ish thousand miles ago" per the shop...I bought her at 200K miles and I've put on 20K miles since then, so, that was done just before I purchased her, along with the Fuel Filter around the same time (Stamped by a Toyota dealership); valve cover gasket has been replaced also, per the tech who looked at it as there is black silicone indicative of a replacement. She's super quiet too! I'll need to get the wheel bearings replaced, but another thing that has moved up the priority list is the metal seal around the windshield...there's a spot that has come undone and the tech believes this is where some water is getting in. So, if that isn't fixed by the rain season (Oh, another month or so up here in Portland) she'll be covered by a tarp as a precaution.


Thanks!
 

Comet

Knower of little, master of less.
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“Where water is getting in.“. I would start there for the electrical Gremlins.
 
Joined
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Charlotte, NC & Alexandria, VA
Thanks for the insight!

Oh, she runs like a top. Multiple LC shops have mentioned how good the engine performs, and after my cooling update, it runs even better. New tires were the first thing in May because they were dangerously bad, then the cooling system along with belts and an oil change. My next job is the Ignition (cap, rotor, plugs, wires). I bought her seven years ago but I'm just now in a position to where I can do the things I want...but, baselining her is my priority before adding armor or a lift ;).

I did find out that the PHH was replaced "about 20-ish thousand miles ago" per the shop...I bought her at 200K miles and I've put on 20K miles since then, so, that was done just before I purchased her, along with the Fuel Filter around the same time (Stamped by a Toyota dealership); valve cover gasket has been replaced also, per the tech who looked at it as there is black silicone indicative of a replacement. She's super quiet too! I'll need to get the wheel bearings replaced, but another thing that has moved up the priority list is the metal seal around the windshield...there's a spot that has come undone and the tech believes this is where some water is getting in. So, if that isn't fixed by the rain season (Oh, another month or so up here in Portland) she'll be covered by a tarp as a precaution.


Thanks!
FWIW, my 80s sit under these (keeps them reasonably dry in the heaviest rain - but I don't live in the PNW):
1665685016785.png


and when they don't, I have custom cut magnetic vinyl over the cowl panel to keep the leaves out:

Covered cowl vents.jpg


Paintable maghnetic vinyl sheet.jpg
 
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Ohhhh, definitely looking into this!

Thanks!
 

RiverCityDave

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The list of electrical gremlins you gave, specifically the ones around the dash, and such imply a ground issue. An EWD and learning to read it Will help, I have the 97 if you dont and need it.

  • Cigarette port not working
  • Light in ashtray not working
  • Clock not working
  • Stereo not working
These are one circuit. It super easy to pop the fuse, check and double check it. I replaced my 12V stock with a blue sea USB and managed to pop the fuse like 4 times while I was sorting the wiring.
  • Green ring around ignition stays on ALL THE TIME and I know it shouldn't
Almost certainly ground and related to above.

  • Rear dome light not working (but middle and front map light DO work)
The rear Map light is not on the same circuit as the front two. This is a ground switched light, so you should always have 12v, the switch assembly themselves fail pretty easily, but did you check the terminals? Sometimes the three way switch contacts corrode or bend as do the prongs that hold the bulb. (Three way being Door, On, Off) If you have 12V at the housing, check the ground, the nearest ground for this is down under the crossmember, and they corrode pretty bad. If you can get it off, scrape it to bare metal and reattach. Also affects brake light function.

  • Right side instrument panel lights not working (But left side of panel lights up)
  • All windows not working. ** From any switch? Or just the driver’s switch? **
  • Sunroof not opening (not even a sound of an attempt when depressing the button) ** wiring here feeds up the same line as the front map light, so if it has power, you SHOULD have power to the switch. Again, have you checked for 12v at the motor? **
These are odd. The instrument panel might just be a bad line, related to the stereo work, if someone was looking to tap into a 12v hot, it would be convenient, You need to trace that back to the last place you have voltage and start looking for a break forward of that. They likely used those vampire clips, and could have cut the wire inadvertently.
  • Antenna not working ** (pretty common, and PROBABLY because of the stereo wiring to auto raise the antenna. Again, go to the last place you have voltage in that circuit and trace forward.) **
  • Side mirror controls do not work ** (PROBABLY unrelated, but we need to see what circuit they feed from to say for sure.) **
Hit me up if you need the EWD.
 
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I noticed mine doesn't have a ground wire between the engine block and the bolt connecting the engine wire harness to the firewall. I'm having similar issues you mentioned
 
Joined
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Messages
439
Location
WA/OR
The list of electrical gremlins you gave, specifically the ones around the dash, and such imply a ground issue. An EWD and learning to read it Will help, I have the 97 if you dont and need it.

  • Cigarette port not working
  • Light in ashtray not working
  • Clock not working
  • Stereo not working
These are one circuit. It super easy to pop the fuse, check and double check it. I replaced my 12V stock with a blue sea USB and managed to pop the fuse like 4 times while I was sorting the wiring.
  • Green ring around ignition stays on ALL THE TIME and I know it shouldn't
Almost certainly ground and related to above.

  • Rear dome light not working (but middle and front map light DO work)
The rear Map light is not on the same circuit as the front two. This is a ground switched light, so you should always have 12v, the switch assembly themselves fail pretty easily, but did you check the terminals? Sometimes the three way switch contacts corrode or bend as do the prongs that hold the bulb. (Three way being Door, On, Off) If you have 12V at the housing, check the ground, the nearest ground for this is down under the crossmember, and they corrode pretty bad. If you can get it off, scrape it to bare metal and reattach. Also affects brake light function.

  • Right side instrument panel lights not working (But left side of panel lights up)
  • All windows not working. ** From any switch? Or just the driver’s switch? **
  • Sunroof not opening (not even a sound of an attempt when depressing the button) ** wiring here feeds up the same line as the front map light, so if it has power, you SHOULD have power to the switch. Again, have you checked for 12v at the motor? **
These are odd. The instrument panel might just be a bad line, related to the stereo work, if someone was looking to tap into a 12v hot, it would be convenient, You need to trace that back to the last place you have voltage and start looking for a break forward of that. They likely used those vampire clips, and could have cut the wire inadvertently.
  • Antenna not working ** (pretty common, and PROBABLY because of the stereo wiring to auto raise the antenna. Again, go to the last place you have voltage in that circuit and trace forward.) **
  • Side mirror controls do not work ** (PROBABLY unrelated, but we need to see what circuit they feed from to say for sure.) **
Hit me up if you need the EWD.

Aplogies for not replying sooner...my office has been busy with meetings and my Operations President came in to town. Plus, life outside of work.

Thanks for the detailed replies...it's appreciated and I'll show my tech when I go into the shop tomorrow.

  • All windows not working. ** From any switch? Or just the driver’s switch? **
    • ***From ANY switch, correct. Doesn't matter if I'm driver or passenger, or in the back, none of the power window buttons work. And yes, I have checked the window lock to be sure, as well as the child safety switch.
      • Additionally, the DOOR LOCK button coming off the same switch panel works and locks all doors, but does NOT lock the rear hatch.


I'm tempted to just buy an entire wiring harness from another MUD member that is known to be completely good and hand it to the shop, which I'm going to ask about tomorrow if we have no clear resolution. We're around 7.5 hours and that's just diagnosis, I think. And I'm OK with that, but the money being funneled into chasing an electrical gremlin was marked for the front end knuckle job for new seals.

  • Tires - Check
  • Baseline as much as I can (Cooling system, ignition, diff oil change, oil change, block flush, etc.) - In Progress
    • Cooling System update - Completed
      • Asin Blue Fan Clutch, Asin Water Pump, Asin Thermostat, Denso Radiator, Wit's End Hoses, PHH (Previously completed), Fuel Fileter (Previously completed), Green coolant, Shell Rotella Oil change with OEM filters
    • Ignition System update - NEXT
      • Spark plugs, wires, cap, rotor, dizzy-o gasket
    • Unforeseen electrical chase - In Progress
  • Awning (Black Rhino 2.5m) - Impulse buy (Costco $85...regularly $385 per Rhino site) - Check
  • Windshield reseal - Moved up in priority per shop
  • Front knuckle (New Seals/rebuild) - Awaiting scheduling

Once mechanically sound:
  • New suspension coils/shocks
  • Possible Front bumper / Rear bumper swing out tire carrier
  • 285 tires
 

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