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AAaagghhh - still no brake lights or turn signals!!
!!@%#&$ - It wasn't the &*%#@@ trailer relay. Apparently that nearly severed connection at the trailer relay fuses was hanging on by a strand or two and there wasn't a problem with the relay. I installed another one and I have all the same issues - no brake lights with headlights off. Left brake light only with Lights on. left rear turn signal only with pressure on brake pedal.
More voltage checks Flasher unit: Left turn signal on: Brown 12.5V Yellow 2-9V flashing Blue .3-9V flashing Right turn signal on: Brown 12V Yellow 6.3V steady Bule 0V Power from Brake Light Switch - Pink wire under dash Left turn signal on: 1.5 - 9V (with flasher) Step on brake: 12 V steady with brake light in rear Right turn signal on: 2.3V steady Press on brake: 12 V but no brake light in rear Turn Signal leads - I disconnected the two tan (brown) wires since they appear to only operate the headlight flashers. Disconnecting them didn't seem to change anything Left turn signal on: Blk/Gr to Green 1.5 - 8V flashing Black to Yellow/Red 11.5V (I think this is power to the turn signal Blk/White to Yellow 1.5 - 9V Right turn signal on: Blk/Gr to Green 6V Black to Yellow/Red 11.5V Blk/White to Yellow 6V I don't know what to make of the above. It could be as simple as a bad flasher ( doesn't seem to be flashing on the rigtht side. It seems like on the right side it's just getting 6V from the flasher. Could be the turn signal switch?? Could be both ??? Guess I'll try a new flasher since that is pretty cheap. Man, I hate electrical stuff. |
Disconnect the trailer side of the trailer relay and apply 12v to each of the two wires and see if the bright filament on each side of the rear of the car come on. Just use a jumper wire to feed the 12v.
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Dan,
Which tail lights do you have ? The round ones or the single lens rectangle . The only reason I ask is because I had similar issues with the rectangle ones. They use the Prince of Darkness bulb sockets and they SUCK ! I happen to see a superformance rear taillight assembly and knew that was the best way. Instead of buying theirs I just fabbed my own. I wanted better bulb sockets rather than those I had so I went to the U pick and found some really cool metal ones out of a 70's car. My problem went away. I know too you better have super good grounds with a glass car. Don't mean to waste your time. I hope you find your issues and get back on the road. Hersh:) |
I have the single bulb rectangular units. Thus the trailer relay that has to be used to allow the single bulb to handle tail light, brake light and turn signal functions.
Patrick - I'll check tomorrow but I think it's something other than the trailer relay. What would be the chances of having two relay that were identically faulty? There is something definately funky going on with the flasher unilt if you look at my voltage readings. Not sure it alone is enough to cause all of my problems. |
Remember the flasher unit "feeds" the turn signal switch. It becomes intermittent under load. You can jumper "across the flasher" and thereby deliver a constant 12v to your signal switch. If you do that, then signaling a turn will not flash the signal lights on the front and back of the car, but it should still light them (constantly, not flashing). I would definitely test your relays with clean input voltage. You know everything from the back lights to the relay works. Next step is test the relay, then test the signal switch, then test the flasher. That's all that's on the circuit -- you will have gone from nose to toes.
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Dan,
I eliminated the trailer reg by doing the two bulb per side. That's what Superformance did too. So in the future you might want to try this approach. I hope you find that miserable little bug and squash it.:D I'm with you on electrical stuff. I just hate it.:confused: Good luck Hersh:) http://www.clubcobra.com/photopost/d...m/image196.jpg |
After reflecting some more on the wiring diagram I'm backing off on the turn signal flasher. It feeds the turn signal power through a common lead so there isn't any reason it would work in one direction and not the other. That leads me to the turn signal unit. I guess I will resume testing around it later today. Probably feed it 12V power as suggested and try switching the L and R rear light leads to see if the symptoms switch sides also
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I then stabbed the fuse outputs to the rear lights again and each one lit up fine. I tried voltage through the old relay and did get partial voltage a couple times - it may be marginally better shape than the new one. I soldiered the connections with the new relay and although I was watching the wire temp I may have induced too more heat on the relay than I expected. Guess I'll order another one from summit. This is why I like mechanical points over electronic distributors. :mad: |
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?
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5 minutes sounds optimistic for me, but OK.
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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. |
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. |
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.
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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. |
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.
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Out of Bob's Electrical Primer - not really practical to bench test the relay. I put it back in the car and have the exact same results as before. Must be something besides the relay. I think I will have ERA send me a new flasher and turn signal unit tomorrow.
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