No Brake lights and Flashing Cruise Control

2008 Tacoma with no brake lights or third light. Checked fuses, bulbs, replaced brake switch and replaced the fuse junction block under the dash twice. Still no lights. Have had to the service department twice and they say it's the junction block but have replaced it twice with ones from a salvage yard. Can't imagine both being bad. Any help would be appreciated!

 

Not much there that you haven't replaced already
Battery to Fuse to Stop Light Switch to Dist Block to Lamps.

Have you taken any voltage readings? You need a voltmeter and start taking readings to find out where the 12 VDC is missing.

The only thing left is the connectors and wires...

 

The service center suggested to bypass the junction block to get power to brake lights. I refused and got a replacement junction block but it didn't help either. The above photo is a copy of the invoice from the service dept.

 

I already have sunk money in two trips to service, brake switch, two replacement junction blocks and bulbs. I really don't think putting a new junction block in will solve the problem and I don't want to bypass the problem.

 

bypass the low brake fluid switch, that sensor might cause issues as well

 

Where is the low brake fluid switch?

 

In the master cylinder brake fluid tank.

 

Reading their description of troubleshooting the problem is indeed the junction block ...

You do realize that the junction block is just a connecting junction between several points.

 

What's odd is yesterday I had to drive the truck for about an hour trip. When I left it was still light out but upon returning home after dark I noticed in my mirror that my brake lights were suddenly working. They worked fine all the way home and once returning home I checked again after turning the truck off and were working fine. This morning I went out and had my wife to check them again and they were not working again. CRAZY!

 

Sounds like a bad connection going to the junction block that comes and goes. Hard to think that you have gotten two defective replacements especially considering what it actually is. I think you have a loose connector going to the block.

 

I've decided today to put a battery charger on the battery to put a charge to it because it's not been cranking over like it used to on cold mornings. I then drove for about 20 min. and checked to see if I had brake lights, low and behold brake lights! I will check them in the morning but is it possible that there is not enough voltage in the battery for brake lights to operate properly even though other lights work and truck starts? My buddy had a car that wouldn't come out of park because of a bad battery while it still started and lights worked.

 

Confidence is not very high that it is a battery problem.

 

One of the most important rules of troubleshooting is to never trust what has been done previously - EVERTHING should be confirmed. Having said that, I would be removing the connector plugs from the brake light switch, and into and out of the junction block. Check the connector pins for damage and the female pins for enough "pin tension", as in, take a very fine wire paper clip, bend it open, and push the end of it into the female pin. Drag should be felt, equal to the others in the connector. If it drops in too easily, a proper contact will not be made, and that pin should be replaced. One of the most common causes of damaged pins is improper testing - usually when someone shoves their multimeter leads into it carelessly.

After all that is tested, recheck all the voltages with all plugs reconnected - it is important to measure voltage with a load on the circuit (all plugs connected, so circuit should be completed), many times a circuit with high resistance will carry enough power to display good voltage on a meter (which draws far less than a milliamp) but drop off to nothing once a few amp load is applied. I don't know how the tech at your dealer tested voltages, but in my experience this gets overlooked way too often.

 

Agree with this! As most ( not all ) mechanics are mechanics and not electronics techs.