Heater/AC Issue Fixes
Discussion
New guy, just imported a 2001 Tuscan to the USA. I've just been going over the car as I knew the HVAC system wasnt working. I found multiple problems that are somewhat easy fixes that could help some people so I figured i'd post them.
1. The heater ECU had a bunch of cracked solder joints. You can't tell by looking at the cirucit board as the cracks are inbetween the connector and interface PCB. The good thing is that just hitting the back solder joints with a soldering iron and adding a little solder fixed all 7 pins that were having issues. Some of the pins had no continuity from the pin to the main board, some of them would go back and forth causing intermitent issues depending on how much pressure you put on the pin.
I removed the two large 1000uF capacitors just to make it easier as I was troubleshooting. Just remove the ECU, then pull it out of the metal housing; there's only 4 screws. Then you can get access to the back of the connector solder joints. To verify if you have a multimeter you can check continuity from each pin to the main board pcb. This cost $0 to fix.
I also added an extra wire for the blower motor return path as the trace was looking a little brown; looks like the trace was undersized.
2. The flapper motor wasn't working once I fixed the ECU. However it worked without the flap attached. This topic has been discussed a lot from what I see, but no one mentions just fixing it without replacing. My problem came down to the shaft on the main gear was slipping. Initially i pushed it back in and put some super glue on it, but it still was slipping a bit under heavy load. The motor comes apart pretty easy, there's just a strap that you can pry off to get the motor seperated from the gears. Then remove the drill out the two rivets to open up the gear case. You you will need to rivet the case back together, but its just two rivets. I had some trouble with the sizing over here in the USA, so I drilled out the holes a little larger to use a size I have easy access to.
I end up taking an angle grinder, cutting through the plastic gear and into the shaft itself on both sides. This creates a 'key' that I filled with jb weld epoxy. This locks the shaft to the gear and should prevent slipping. We'll see how it holds up long term, but if it doesn't I'll drill it and put a pin through the shaft and gear. Once the epoxy is dried i basically sanded it down just enough to make sure its not hitting on the other gears. The goal was to leave as much material as possible for support.
It's pretty easy to take apart the motor once its its out
Anwyays....I may do some other fun electronic mods over then next year or two to these cars as support for the ECU's seems to be low. If anyone has a broken gauge cluster or has a source on one for cheap, let me know. I'd like to reverse engineer the PCBs and maybe put it a more modern LCD screen.
1. The heater ECU had a bunch of cracked solder joints. You can't tell by looking at the cirucit board as the cracks are inbetween the connector and interface PCB. The good thing is that just hitting the back solder joints with a soldering iron and adding a little solder fixed all 7 pins that were having issues. Some of the pins had no continuity from the pin to the main board, some of them would go back and forth causing intermitent issues depending on how much pressure you put on the pin.
I removed the two large 1000uF capacitors just to make it easier as I was troubleshooting. Just remove the ECU, then pull it out of the metal housing; there's only 4 screws. Then you can get access to the back of the connector solder joints. To verify if you have a multimeter you can check continuity from each pin to the main board pcb. This cost $0 to fix.
I also added an extra wire for the blower motor return path as the trace was looking a little brown; looks like the trace was undersized.
2. The flapper motor wasn't working once I fixed the ECU. However it worked without the flap attached. This topic has been discussed a lot from what I see, but no one mentions just fixing it without replacing. My problem came down to the shaft on the main gear was slipping. Initially i pushed it back in and put some super glue on it, but it still was slipping a bit under heavy load. The motor comes apart pretty easy, there's just a strap that you can pry off to get the motor seperated from the gears. Then remove the drill out the two rivets to open up the gear case. You you will need to rivet the case back together, but its just two rivets. I had some trouble with the sizing over here in the USA, so I drilled out the holes a little larger to use a size I have easy access to.
I end up taking an angle grinder, cutting through the plastic gear and into the shaft itself on both sides. This creates a 'key' that I filled with jb weld epoxy. This locks the shaft to the gear and should prevent slipping. We'll see how it holds up long term, but if it doesn't I'll drill it and put a pin through the shaft and gear. Once the epoxy is dried i basically sanded it down just enough to make sure its not hitting on the other gears. The goal was to leave as much material as possible for support.
It's pretty easy to take apart the motor once its its out
Anwyays....I may do some other fun electronic mods over then next year or two to these cars as support for the ECU's seems to be low. If anyone has a broken gauge cluster or has a source on one for cheap, let me know. I'd like to reverse engineer the PCBs and maybe put it a more modern LCD screen.
Edited by czwalga on Tuesday 14th April 15:48
As someone with an intermittent heater/blower fault at the moment, this is really interesting. Thanks for the description - it's encouraged me to have a look in the ECU and see if it's a simple fix. Mine's already been repaired at some point in the past, having burned out the motor pins in the connector by the look of things.
Unfortunately, the pictures (or videos?) posted say they can't be viewed in my region (UK).
Unfortunately, the pictures (or videos?) posted say they can't be viewed in my region (UK).
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