Tbc 2a Fuse Keeps Blowing 15 Amp Please Help Me!

xixfishxix · June 2, 2007

2004 Escalade 6.0 awd - new optimus battery (red top) and had altenator and battery checked - everything is normal on their tests.

The TBC 2A fuse controls the dashboard lights it calls for a 15 amp fuse which keeps blowing. If I put a 20 amp fuse in it will work good for a few minutes and then the dash board (heater lights, dash lights, rear control lights etc..) all start to blink.

Actually the speedometer will glow brighter when the other lights dim out and then the other lights will come back to normal and so will the speedometer lights. So it fluctuates power where the speedometer flashes brighter when the other lights dim and when the other dash lights come back to normal the speedometer dims down to normal levels. This blinking is at a rate of about 3 seconds, so - flash bright and dim out other dash lights for 3 seconds then - dash lights come back to normal light and speedometer dims to normal level for 2 seconds etc....

With a 20 amp fuse in there I can dim the dash lights but it is erratic where it isnt a steady dim it is sketchy at best while adjusting the dimming wheel.

If I put a 15 amp (what it calls for) in the TBC 2A slot, the second I turn over the key it pops it. I do not even know where to start diagnosing the problem.

If it were a ground issue wouldnt it blow the 20 amp fuse too?

What kind of "short circuit" could this be? Does anyone one know where I would look to see what exactly is controlled by the TBC 2A 15 amp fuse?

98 Z71 SLT · June 3, 2007

Just performed a bulletin search. You can fix the problem yourself at home.

Left instrument panel fuse block. CAREFULLY trace the wiring harness from the bottom of the fuse block to a clip. In those 8 inches of harness, GM states they are finding short-to-grounds, which obviously will pop fuses.

So, you have a wire rubbing a clip, causing a short. Check that harness and fix it.

xixfishxix · June 3, 2007

If it were a "short to ground" issue, wouldnt it blow the 20 amp fuse too?

Thanks

az'03Silverado · June 3, 2007

Not necessarily. If the circuit is just arcing, the instantanious current may be too high for the 15A fuse but the 20A may handle it. This may explain why the lights are flickering. As the circuit arcs, the lights flicker but the 20A fuse can hold together. Check the wiring for any chaffing, exposed conductor, etc.

xixfishxix · June 4, 2007

2 quick questions before i start to butcher my truck (omg hahaah)

1. the picture - what angle is that? is that from inside the truck but towards the back of the ip and the wires run down the door frame by the emergency brake release?

2. If I were to cut every wire (omg i am really thinking about it) and then put in a 15 amp fuse and wire them back together (splicing) 1 at a time would this hurt anything, having the wires cut and turning the truck on over and over to find the problem wire.

Thanks so much for all your help here guys, just blew all my money on the goodies i put in the truck and cant afford the dealer raping me. FISH

kroc33 · June 4, 2007

Get yourself an electrical tester and check the wires for shorts to ground with that. Since you know which fuse is popping you should be able to trace the wire and hopefully find a spot where it is rubbing on something metal under the dash.

xixfishxix · June 6, 2007

(I feel dumb for asking this but...) How do I test the wire for a "short to ground"?

I have a digital multimeter Like this ONE

What setting (normal 20v or less setting) and then ground to ground and hot to each wire? If so then what would I be looking for on the readout - will it be freaking out (lots of numbers) or I dont know - a grounded wire will show a negative on the readout, but what would a "short to ground" show?

Also how would power or ground be registering in these lines if it blows the fuse doesnt that Fuse stop the current from going through - thereby giving me no reading because its a dead wire? Once the fuse blows then there is no more short to ground cause there is no power right?

Hopefully I am just retarded and you guys have a simple answer. Thanks for all your help guys. Fish

chiefgeek · July 20, 2007

I have an 06 Silverado that just started blowin the airbag fuse. Dealer tells me it is because I have installed aftermarket stereo, speakers, and amps. Could this really be the cause or is the dealer just trying to pass the buck?

Thanks

redvett · July 20, 2007

I have an 06 Silverado that just started blowin the airbag fuse. Dealer tells me it is because I have installed aftermarket stereo, speakers, and amps. Could this really be the cause or is the dealer just trying to pass the buck?

Thanks

If your stereo was tied into the SDM circuit yes if not no. If you had your stereo installed by a shop it my be tied in and those guys are butchers and shouldn't be allowed to wire anything.

If you look in the GM disclaimer any non OEM installed equipment is your responsibility. With the highly integrated systems its very easy to interfere with another system.

chiefgeek · July 20, 2007

I installed the head unit with a gm databus adapter myself. I soldered and shrinkwrapped al connections. I then let the local car toys install amps, speakers, etc.the headunit, databus adapter, and install kit came from crutchfield. how does that affect your original response?

chiefgeek · July 24, 2007

I have a new development, the dealer says that when the wires were run into the door a drain was knocked loose and water is pooring into the floorboard which supposedly soaked the SDM module under the passenger seat.

I don't know of any drains in the "A-Pillar" that could have been messed up by running wires. Has anyone heard of these drains in the "A-Pillar".