Jeepwalker
Well-Known Member
- Messages
- 980
- Location
- WI
Hello. New member here.
Just went through the 'famous' (and frustrating!) window lock/switch flake-out situation where the driver's window/lock wouldn't work properly after removing the driver's side switch assembly ...or battery. I know this is well documented on the internet and Colorado truck forums. The usual fixes didn't work for me, including draining capacitors or BCM memory, etc. Thought I'd share what I discovered and a repair I did, perhaps it may help others. Especially owners who may be faced with possibly buying an expensive switch as a last resort.
I decided to put some electronics test equipment to use: I measured fairly high ESR values on the two main capacitors, especially the 50v capacitor ...which was WAY out of spec (see values below). A little background FWIW: Electrolytic capacitors have a conductive 'goo' inside them. Heat, especially years of hot car-interior-heat, would be particularly hard on a capacitor's lifespan. Same goes for capacitors in a TV, Computer, DVD player, etc and much worse if subjected to excessive heat. If capacitors leak, burst, dome or dry-out, the result can be a down-stream out-of-spec voltage pattern or 'noise', which can lead to whacky logic in microprocessors which may not get the signal they 'expect'. Operating ESR values should be considerably less than the max values. An electronic repair technician's first-look of a troubled circuit board is usually to inspect for problems with electrolytic capacitors. They fail often and are also easy and quick to observe, then measure. I'm not going to go into what ESR is or means, testing etc, you can google that. Inexpensive testers (and replacement capacitors) can be purchased off ebay.
Anyway, I had exact replacement capacitors on-hand and soldered in the new caps. It all worked when re-installed the next day. Great! I must disclose I *did* leave the vehicle sit overnight with the battery unhooked because it was late by the time I finished the project. However lengthy battery draining (and BCM draining) had not worked for me prior. So I cannot say with certainty this *was* my culprit or if my switch would have worked anyway the next day. I did not perform other tests of the board. Will a flake-out happen again if I remove my switch/batt in the future? Probably. The problem seems to be a 'baked-in' residual BCM memory and handshake issue. But hopefully if/when it does occur, the normal BCM voltage-draining-trick will work for me. However, what *is* known, is that the capacitors (in my case) were out of spec, especially the 50v unit. So, take that for what it is. If an owner has a flaky window/lock switch where other remedies haven't worked, this is definitely something to look into. Good luck!
Just went through the 'famous' (and frustrating!) window lock/switch flake-out situation where the driver's window/lock wouldn't work properly after removing the driver's side switch assembly ...or battery. I know this is well documented on the internet and Colorado truck forums. The usual fixes didn't work for me, including draining capacitors or BCM memory, etc. Thought I'd share what I discovered and a repair I did, perhaps it may help others. Especially owners who may be faced with possibly buying an expensive switch as a last resort.
I decided to put some electronics test equipment to use: I measured fairly high ESR values on the two main capacitors, especially the 50v capacitor ...which was WAY out of spec (see values below). A little background FWIW: Electrolytic capacitors have a conductive 'goo' inside them. Heat, especially years of hot car-interior-heat, would be particularly hard on a capacitor's lifespan. Same goes for capacitors in a TV, Computer, DVD player, etc and much worse if subjected to excessive heat. If capacitors leak, burst, dome or dry-out, the result can be a down-stream out-of-spec voltage pattern or 'noise', which can lead to whacky logic in microprocessors which may not get the signal they 'expect'. Operating ESR values should be considerably less than the max values. An electronic repair technician's first-look of a troubled circuit board is usually to inspect for problems with electrolytic capacitors. They fail often and are also easy and quick to observe, then measure. I'm not going to go into what ESR is or means, testing etc, you can google that. Inexpensive testers (and replacement capacitors) can be purchased off ebay.
Anyway, I had exact replacement capacitors on-hand and soldered in the new caps. It all worked when re-installed the next day. Great! I must disclose I *did* leave the vehicle sit overnight with the battery unhooked because it was late by the time I finished the project. However lengthy battery draining (and BCM draining) had not worked for me prior. So I cannot say with certainty this *was* my culprit or if my switch would have worked anyway the next day. I did not perform other tests of the board. Will a flake-out happen again if I remove my switch/batt in the future? Probably. The problem seems to be a 'baked-in' residual BCM memory and handshake issue. But hopefully if/when it does occur, the normal BCM voltage-draining-trick will work for me. However, what *is* known, is that the capacitors (in my case) were out of spec, especially the 50v unit. So, take that for what it is. If an owner has a flaky window/lock switch where other remedies haven't worked, this is definitely something to look into. Good luck!
| Cap_Value/Size | Tested_ESR | Max_ESR | NewCap_ESR | |
| 16v,47uf | 1.6 | 1.8 | .96 | |
| 50v,33uf | 2.2 | .6 | .13 | |
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