Okay, so I've come across another issue as time has gone on. To give a bit of a background to this, I installed 1968 Mercury Cougar Lights into the back of my Comet to give it a slightly different look. I've wired the lights in parallel as to not mess with the brightness but I've run into an issue. From the start, whenever I pressed on the brakes, all the lights in the car would dim. Not significantly, but a noticeable amount to me. All the lights. The headlights, side markers, interior instrument lights, dome lights, etc. It wasn't until recently that I began having another problem that's sort of become quite a nuisance as well as elusive. If the car is idling, and I press the brakes for long enough, all the lights start to flicker on and off rapidly. If I rev up the engine a little, it seems this goes away. It only happens while idling or while the vehicle is off. The only lights that don't flicker are the headlights. Every time the rest of the lights turn off, they get significantly brighter. I've tried ohming out the chassis ground wire, but have got .5 ohms of resistance, and I cannot imagine that being too much for the system to handle. I did notice though the other day, that if you listen closely while the engine is off, you can hear a clicking noise (sort of like a blinker click) somewhere on the driver's side of the car that is in sync with the flickers. Does this issue seem like a bad ground somewhere? It's puzzling to me. Has anybody else had a similar problem in the past and corrected it somehow? It only happens after holding the brakes for significant amount of time (such as the time spent at a red light) Every once and while though it won't do it.
No. The problem never existed before them. But the problem is, I installed them when I pulled out the entire engine and wiring harness, so I'm not entirely sure where things went wrong since everything was done at once. (Tach, new gauge cluster, new msd ignition)
Sooo those have three bulbs on each side vs one, right??? If so you are drawing 3x the current of orig design... You stated wiring was removed... Just removed and reinstalled or wired differently???
Yes. They have 3 bulbs on each side. The wiring was just removed and added to. I did not rewire anything major other than the extra lightbulbs. Which are in parallel currently. Each of them have their own way to the ground wire. I'm using what appears to be a 65 amp alternator but I have not checked the battery life. I was assuming it was still good since it was just purchased, maybe last September. I wouldn't be the least bit surprised if it was something I screwed up during the installation.
Problem isn't alt, it's undersized wiring and overloaded running/brake lamp circuit breaker in headlamp switch... To verify hold brake till problem starts and see if horn is intermittent as well...
yeah i agree with Krazy Comet. when you wire parallel the amperage goes up with every leg you add, because of the lowered resistance because you gave the current more paths to go through. if you wire in series the amperage stays the same through the circuit, but will go down from the original amperage because of the added resistance...
So then what would be the best plan of action to fix that? After reading his comment I couldn't agree more, and can't believe I didn't think of the amperage spike when I was installing them. If i'm correct though, wiring them in series would make them significantly dimmer across the board, but how else would I go about fixing the issue? Would I have to run a whole new brake lamp circut with thicker gauge wire or is there maybe a work around? For a while, the lights did work just fine. (For a couple weeks) But then, one night this issue started happening, and since then it's been constant.
Agreed... The ultimate fix would be use the relay mod used to remove load from headlight switch... Mostly the idea for that mod is give brighter lights due to less wiring resistance but has added benefit of reducing load on factory harness & HL switch(I did mod to my Comet)... Would require a fused hot lead run from battery(solenoid) to trunk, otherwise the connections that would operate relays are already part of circuit... Only need to use relays on high side(stop/signal)of bulbs as the four extra running lights don't draw any more current than one stop lamp bulb(that now are never on orig wiring), so orig wiring & HL switch should be able to handle that...
You need to fix the original problem rather than put "band-aids" on it like LED lights, different dimmer, etc. You said the problem existed before you installed the cougar lights. The stock wiring and circuitry should be able to handle the 4 extra 1157 bulbs that have been added if everything is wired correctly and functioning properly. How do I know this? Because a friend of mine did the same thing on his Maverick ('65 T-bird tail lights). He says he didn't change any of the original wiring and has no problems. Of course the brake lights are sequential, so there isn't as much of a "surge" when the brake lights are activated.
Well you're are reading it differently than me, I understand it started two weeks after the Cougar lights were installed... The wiring isn't as much the problem as the circuit breaker in the head light switch is dropping out... Still the 3X load on the wiring will cause a voltage drop that makes light flicker just using brakes(try wiring four more lights to your car and see what happens)... The click is the breaker in headlamp switch opening and resetting...
You are correct, however he said this: "I installed them when I pulled out the entire engine and wiring harness, so I'm not entirely sure where things went wrong since everything was done at once." Perhaps a new headlamp switch is the cure.
