AAaagghhh - still no brake lights or turn signals!!

[patrickt]

Tell you what... when the third relay comes, let's first bench test it on your work table with a 12v battery, two 12v brake light bulbs, and some wire. It'll only take five minutes to do that. OK?

[DanEC]

5 minutes sounds optimistic for me, but OK.

[DanEC]

Patrick - still awaiting the next shipment of trailer relays from Summit (this time I ordered two of them) but I did a little more testing.

I think I verified this before but when the brake is pressed I have power at the red wire entering the trailer relay. Applying 12V at the fuse connections to the rear lights gets me a brake light there. So brake light circuits are good from both ends to the relay.

I went back to the flasher unit - with ignition on, I get 12V at both the brown and yellow wires. Brown is power from down by the brake light switch and yellow feeds the turn signal switch. However, with my test light I get a bright bulb on the brown and a much weaker bulb on the yellow. I guess this is due to the flasher relay. It doesn't appear possbile to stimulate the flasher into activation by merely applying 12 power to it - not sure what that takes. I also tested the resistance between the yellow and brown leads and got 400 ohms, but again - I guess that has something to do with the flasher unit itself.

I next applied 12V power to the Y/R lead to the turn signal switch, and checked for power at the green and yellow wires leading to the fuses. On the left turn signal I got a lit test lamp on the left wire going to the trailer relay. On the right signal I got a lit test lamp on the right side wire going to the trailer relay. Neither L or R signal generated a bright bulb. This makes it appear the turn signals may be OK.

I also broke apart the original trailer relay and fooled around with it. Interestingly, it has a row or resistors/diodes/who know what else fed off of the red, yellow and green leads and not a one of them had any continuity across the legs. Every last one of them was dead as could be. I couldn't get an Ohm meter tone across any of them.

I'm beginning think that the 2A quick blow fuses are on the wrong side of the trailer relay. It looks like this thing needs some fused protection on the incoming sied rather than the outgoing circuits to the rear lights.

I haven't heard back any further from Bob. I hoped he might have some observation or suggestion based on his knowledge of the system.

Hopefully the new relays will be here Monday. I think I will install the next one without soldering the connections in case the heat from that is part of the problem.

[patrickt]

You can not check the flasher without putting a load on it, like two light bulbs. The load allows a little heating element inside the flasher to heat up, which then makes a piece of metal get hot and go "twaanggg" when it warps over and short circuits the heater element, causing it to cool down, and the piece of metal then contracts back to it's original position. The heater then does it again. That's how it turns the circuit to the bulbs on and off as that little piece of metal turns your lights on and off as it gets hot and cold.

The two fast blow fuses sit between the rear lights and the relay. The fuses under the hood sit between your battery and the relay. So, it's fused on both sides.

We will bench test your next relay on the kitchen table using a light bulb, some wire, and a battery. It will be easy to do.

[DanEC]

Yes, but that 15A fuse still allows a pretty good load on that trailer relay. it seems there has to be some other component or something causing the relays to burn out - it's surely not just bad karma.

[DanEC]

Received the two additional trailer relays today and tried bench testing them - heavy emphasis on tried. First, I tried checking continuity through them and got nothing - probably not unexpected for a transister relay.

Then I hooked up a jumper from fuse 5 to the red wire and my test lamp to a ground and checked each of the two trailer outputs for any sign of life - nada. Then I hooked power to the green and yellow inputs alternately and checked the outputs with my test light - again nada - no sign of life. Checked the fuse 5 connection to the relay lead each time with my test light and got light.

Then I hooked it up to my battery charger set on 2 Amps and repeated the same tests with my test light hooked up to the ground side - got no sign of life at all.

Tested the other relay I received with the charger and got nothing from it also.

Either all of these things are all dead or they take some sort of load to make them operate like the flasher or the voltage regulator. But what would it be? The brake light power is from a simple switch and the light bulbs shouldn't be much load. The turn signals get power from the flasher but from most of my testing it's not even a full 12 volts.

Not sure where to go from here.

[patrickt]

You must do the bench testing with actual bulbs, of similar wattage to the bulbs in your car. A little "circuit test bulb" does not create enough amperage through the relay for a proper test. Nor does a Volt Ohm Meter.

[ray humbel]

I was having a heck of a time trying to figure my problem with brake and turn signal lites working and not. After trying everything I changed the turn signal colum arm switch. You can get one from Finish Line. I got mine from Shelby American $130.