2000 GMT400 CREW CAB SFA SWAP-The Warden: Fuel leak fixed and awaiting surgery…

[skunked]

are you having issues with any other lights or just the brake lights? Have you looked at a schematic or have one to post?

 

[GWeakland620]

I'll post a pick of the diagram I have at home. No, no other light issues.

 

[campfire]

So bare with me on this next part, as I am not a fart smeller.

I have been having an issue with the torque converter not locking up once my truck reaches overdrive. Took it to a tranny shop to have him drive it and tell me what's going on. He said everything is working just fine, until I reach overdrive. He said while driving the truck, the scanner kept throwing a code saying "brake switch voltage high", which in turn will prevent the TC from locking up.

So a little more back story....

A few months after I bought this truck, the brake switch stopped working and I lost brake lights. I replaced it, and went on my way. About a month ago I started having brake light issues again. Intermittent lights working. Then completely stopped working all together. Replaced the brake switch last Sunday, and we are good to go. No more brake light issue.

So now knowing what I do, these problems are all related. I am having high voltage issues with the brake switch, which is causing early failure to the switch itself as well as causing TC lockup issues.

Any input, or suggestion on where to start with this? The trans shop suggested tracing some wires to see if I had any broken, or frayed wires.

The answer to your problem is a stick-shift.





Doesn't "Brake switch voltage high" mean the output of the switch is high (on) improperly (instead of the input)? The pieces you've shared don't make perfect sense yet. If the switch is not illuminating the brake lights, it should not be interfering with the T/C. If it is preventing T/C lockup, the brake lights should be illuminated constantly.

Unless there are 2 different switches (not sure on your model, but I only have one). If so, perhaps you messed the T/C switch up while replacing the brake light switch. Maybe? Or broke a wire while reinstalling the plug on the switch?

 

[GWeakland620]

Ended up messing with this today and found that I had a short in my trailer brake controller causing this high resistance issue. Disconnected the wires that were spliced into the brake wiring harness, and no more issue.

I've honestly never heard of anything like this before.

Definitely had me scratching my head.

In other news. Parts ordering for the sfa swap will start on Monday

 

[campfire]

Ended up messing with this today and found that I had a short in my trailer brake controller causing this high resistance issue. Disconnected the wires that were spliced into the brake wiring harness, and no more issue.

I've honestly never heard of anything like this before.

Definitely had me scratching my head.

Wait...high resistance? I though you had a high voltage issue

In other news. Parts ordering for the sfa swap will start on Monday

Saweet!

 

[GWeakland620]

Yeah, me and wiring don't play well together.

 

[GWeakland620]

Tires came in today. Pictures make them look low on tread, but they are right at about the 80% mark. They have a 2015 DOT date. Should do fine for a bit.

 

[GWeakland620]

Would @tRustyK5 or @mrk5 like to move this to the garage? I think there will be enough tech, that more should be able to see it. Thanks.

 

[mrk5]

Would @tRustyK5 or @mrk5 like to move this to the garage? I think there will be enough tech, that more should be able to see it. Thanks.

The Garage or Driveway?

 

[GWeakland620]

Whichever you feel fits. I thought the driveway was usually more for the real square bodies, and actual build threads. This is more of a bs/informational thread. But will have a bit of my sfa swap documented. It's up to you.

 

[skunked]

Yeah, me and wiring don't play well together.

More often than not, wiring issues usually have something do with some PO modification (hack job) on these older trucks. Stereo's, trailer lights/brakes, alarms, auxiliary lighting, etc. I just spent a couple hours de-fuching some wiring on my 97, damn doors would lock on their own randomly, traced that back to an alarm system that was installed previously that I didn't even know was there.

 

[GWeakland620]

That was actually how I came to find the problem. I saw no visual wiring issues, so I just thought "what aftermarket stuff might be on here".

 

[GWeakland620]

So now that I don't have any trailer brakes, what's a good route to go for a unit that will last a while? Also, what's a good route to go with splicing into the brake wiring?

 

[skunked]

You're looking for an electric brake controller correct?

 

[campfire]

So now that I don't have any trailer brakes, what's a good route to go for a unit that will last a while? Also, what's a good route to go with splicing into the brake wiring?

Best solution? Don't mess with the wiring. At all.

Beyond that you could probably just use the controller that you own. With proper wiring, of course.

 

[skunked]

The controller I've had in my 03 2500 and swapped over to the 02 Tahoe plugs into the stock harness. Really easy....

 

[GWeakland620]

From what I understand, the newer controllers plug into the harness. I wish these ones did.

So I'm wondering if the controller actually has a short in it, or if it was the wiring itself. All the connections looks fairly decent other than the one that spliced into the brake light wiring.

 

[skunked]

quality brake controllers are worth the extra few bucks.

 

[GWeakland620]

That's what I was thinking.

 

[skunked]

Here's the one I have http://www.amazon.com/Tekonsha-90885-Prodigy-Electronic-Control/dp/B002YIACG8

Works good, came with a harness. Might be something better out now, but at the time I bought this it was a good controller for the $$.