My 1987 SR5 ROAR (Restoration Of A Restoration) thread
#182
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Indeed, and thanks for your previous pointer on where to find the resistor. Once you contort yourself deep enough under the glove box to see it, it's just a matter of one screw and one connector to get it out. Easy!
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Saccyclone (08-18-2024)
#183
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The following users liked this post:
Saccyclone (08-18-2024)
#184
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I finally figured out the power window issue. With the replacement door lock control module in place, I was now getting 12V to the master power window switch, as expected. But some windows worked in one direction, but not other. Yet when I applied 12V to either power window motor, the windows went up and down like gangbusters. So, obviously it was an issue with the power window switches.
I rechecked all the contacts again with my DVM, and noticed that one of them was close to 5 ohms, as I mentioned in post 178. And sure enough, that was the passenger "window up" contact, which was the one that didn't work properly. Earlier, I didn't think that the 5 ohm resistance would have a big impact, but then I measured the resistance of the power window motors, and found them to be 1.5-2 ohms. So, with a 12V supply and a 2 ohm resistance, the motors should be getting 6A of current through them. But, add a 5 ohm resistance from the switches, and the current drops to under 2A. No wonder the windows were sluggish or simply stalled; most of the power was being dissipated in the switch as heat.
So I again took apart the master switch, cleaned and readjusted the contacts, and now that switch works great on both windows in both directions. But the passenger side switch did not want to raise the passenger window. Unfortunately that switch was epoxied and could not be disassembled. Or I should say that I tried to disassemble it, but the switch disintegrated. So I have a replacement switch on the way to me.
In the meantime, I decided to try to figure out why my dome light was not coming on when the driver side door was opened (it came on just fine with the passenger door open). Yet I knew that the driver door switch worked, because the courtesy light on the door came on with the driver door open. Some guidance from the 1st Gen 4Runner Mafia FB group led me to look at the Seat Belt Warning Relay, aka the Buzzer, that's mounted right off the steering column. According to the schematic, the driver side door switch needs that relay to be operational for it to trigger the dome light. Sure enough, someone clipped two wires leading to that relay, probably to avoid the world's most obnoxious buzzing sound:
I spliced the wires back together, and was indeed treated to that horrible "chipmunk in a vise" sound that others have mentioned (I'll spare you the sound clip). So, I took the buzzer apart:
Some folks just bend down the contact below to disable the buzzing sound:
I decided to stick two layers of electrical tape in there, in case someone ever wants to make it operational again:
So now the dome light works with the driver door open. And an unexpected benefit, the "fasten belts" light now works:
I rechecked all the contacts again with my DVM, and noticed that one of them was close to 5 ohms, as I mentioned in post 178. And sure enough, that was the passenger "window up" contact, which was the one that didn't work properly. Earlier, I didn't think that the 5 ohm resistance would have a big impact, but then I measured the resistance of the power window motors, and found them to be 1.5-2 ohms. So, with a 12V supply and a 2 ohm resistance, the motors should be getting 6A of current through them. But, add a 5 ohm resistance from the switches, and the current drops to under 2A. No wonder the windows were sluggish or simply stalled; most of the power was being dissipated in the switch as heat.
So I again took apart the master switch, cleaned and readjusted the contacts, and now that switch works great on both windows in both directions. But the passenger side switch did not want to raise the passenger window. Unfortunately that switch was epoxied and could not be disassembled. Or I should say that I tried to disassemble it, but the switch disintegrated. So I have a replacement switch on the way to me.
In the meantime, I decided to try to figure out why my dome light was not coming on when the driver side door was opened (it came on just fine with the passenger door open). Yet I knew that the driver door switch worked, because the courtesy light on the door came on with the driver door open. Some guidance from the 1st Gen 4Runner Mafia FB group led me to look at the Seat Belt Warning Relay, aka the Buzzer, that's mounted right off the steering column. According to the schematic, the driver side door switch needs that relay to be operational for it to trigger the dome light. Sure enough, someone clipped two wires leading to that relay, probably to avoid the world's most obnoxious buzzing sound:
I spliced the wires back together, and was indeed treated to that horrible "chipmunk in a vise" sound that others have mentioned (I'll spare you the sound clip). So, I took the buzzer apart:
Some folks just bend down the contact below to disable the buzzing sound:
I decided to stick two layers of electrical tape in there, in case someone ever wants to make it operational again:
So now the dome light works with the driver door open. And an unexpected benefit, the "fasten belts" light now works:
Last edited by 4Runner4Leon; 08-24-2024 at 07:10 AM.
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