When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
John I am also having problems with the spoiler I was needing to know how did you find it was these caps in fault,,,,, I am going to have mine checked I have a 90 C 2 a few post on the links here the motor runs great on it owns for a time period maybe 3 sets at 20 secs each up and down and them nothing would these failed caps cause this ?????? I plugged in the unit today ran it up and down motor only worked as should I have the unit on Tore B page and wondering the large yellow waffer I cannot recall what it is called but used to take up the inrush of current if it got hot enough would it stop the spoiler from rasing.. a thought . the 3 caps you took them out of the pcb and checked them and found to be bad good work
Randy, intermittent faults are the hardest to fix. When I get a box to repair, I first check it’s actually faulty. If it is, I just replace all six capacitors and the two relay drive transistors. They are all so cheap, it’s quicker to do that. Did you replace the capacitors or just refit them.
Randy, intermittent faults are the hardest to fix. When I get a box to repair, I first check it’s actually faulty. If it is, I just replace all six capacitors and the two relay drive transistors. They are all so cheap, it’s quicker to do that. Did you replace the capacitors or just refit them.
This may be a *very* dumb question but what voltage are these capacitors?
Randy, intermittent faults are the hardest to fix. When I get a box to repair, I first check it’s actually faulty. If it is, I just replace all six capacitors and the two relay drive transistors. They are all so cheap, it’s quicker to do that. Did you replace the capacitors or just refit them.
It will depend what your local supplier has in stock. My 220uF is 16v, 47uF is 25v and 4.7uF is 50v. I’d like more margin for the 16V but that was the only local option. 25v and above is fine for a car.
I recap all capacitors and it seems to works on bench with Hz generator, BUT doesn't work on car. I did lot of investigations and I compared with a safe/working unit and I found that the 50V MOV is faulty. Good ECU = 0.2R on MOV, faulty is few ohms (8R ) So there is not enough volts at outpout to move motor.
I had a look on RS & Elements14 but all MOV are with high internal resistance. The MOV we have on this spoiler ECU is very low internal resistor.
Anybody's there could help with reference of this MOV or more tech info ?
I recap all capacitors and it seems to works on bench with Hz generator, BUT doesn't work on car. I did lot of investigations and I compared with a safe/working unit and I found that the 50V MOV is faulty. Good ECU = 0.2R on MOV, faulty is few ohms (8R ) So there is not enough volts at outpout to move motor.
I had a look on RS & Elements14 but all MOV are with high internal resistance. The MOV we have on this spoiler ECU is very low internal resistor.
Anybody's there could help with reference of this MOV or more tech info ?
Regards,
GeD
It's not always as simple as just replacing the capacitors, especially when the circuit board is bad.
If you feel the MOV, a semiconductor transient suppressor, is bad, then just remove it for testing the spoiler.
It only protects the board circuitry from voltage spikes from the switching of the spoiler motor on/off.
I don't think that's an MOV. On my board it's labelled as 50V 1331 BC3J with "Mexico" printed on the otherside. It reads 0.148 ohms at room temp.
It's a protective device but in the circuit in series with ground and the low side of the motor, telling me that it's a PTC thermistor. MOV have high resistance than go low with temp. and are in parallel of the load.
I made an error in my schematic posted above.
To test your theory about the failed component, you can remove the item from the circuit and replace it with a jumper wire. Change out the 15 Amp fuse at position #37 in the front fuse box to the 3 Amp fuse to protect the module if something else is wrong, and then test the spoiler function.
I don't think that's an MOV. On my board it's labelled as 50V 1331 BC3J with "Mexico" printed on the otherside. It reads 0.148 ohms at room temp.
It's a protective device but in the circuit in series with ground and the low side of the motor, telling me that it's a PTC thermistor. MOV have high resistance than go low with temp. and are in parallel of the load.
I made an error in my schematic posted above.
Correct, it's a thermistor (yellow device) to limit the motor current, and avoid damaging the spoiler module when powering the motor, e.g. motor startup current.
There's a transient suppressor (blue) in parallel with the thermistor.
I swap PPTC dead (the one with 8 ohms) with a brand new one with internal resistor = 0.12R and I did some tests onto my 964...
With the first PPTC with 8R > spoiler moves only1 or 2 seconds than freese (not enough power)
With the new PPTC with 0.12R > spoiler moves UP / DOWN few times with no stop.
So that proove that my PPTC was dead and that I must investigate now to find another PPTC, smaller, because the 3.75A I used is 20 mm diameter, and this is too big for the box, the dead one was only 17.5 mm, So I need a smaller one (in size) that approx 2.5/3A .
The yellow parts dead because of initial problems with dead capacitors + dead transistors BC337-40 but this was already fixed. The spoiler unit worked well on bench, always, but not on car. What was the difference? on bench I use a 2 direction motor that drain less that 0.5A... but spoiler unit did not worked onto car with bigger motor.
05-03-2023, 04:55 AM
