Doug Horvath

brake lights and hazard flashers quit working when I had a problem w/ the combo switch that controls the head/parking lights... I figured out why the parking lights quit working and can make them come on but not the brake lights or hazard lights.... any thoughts..... there does not seem to be power at the brake light switch yet the fuse is good... so .... hmm

beg3yrs

Couple of things here.

1) If your front lights are flashing but not the rear ones, I'd suspect the ground connection at the back of the car. It's common to both systems.

2) You said fuse was good but no power to the brake light switch. Did you just inspect the fuse or did you check for voltage on both sides of the fuse, at the connectors, not the fuse itself? The fuse blocks get dirty and corroded over time. If that turns out to be your problem, take the time to clean all your fuse connections.

3) I don't know what you did to fix your head/parking lights but the combo switch does not come into play with the brakes and flashers. I do notice the C2 and C6 connectors on the big junction block in the passenger footwell are significantly involved in these systems. Were you futzing around in there?

rogerz

hard to give advice when not knowing the car asked about

if you would really like answers that would help you and avoid flames give the following info when you post: year of car, n/a or turbo engine, stick or slushbox, digital or analog dash. Most of us can tell by the year what model you have ie 85T is a turbo z31. Z cars come in many flavors and they are all different. example 84,85,86 Z31's pretty comparable. there were changes in 87,88,89. in addition 300ZX can refer to two completly different cars the Z31 and the Z32. No mindreaders here the more info you can post the more likely you get a cogent useful answer. The cars with L engine (straight six) changed almost yearly from their introduction. A 240Z and and a 280Z have similarities but they can also have wide variance.

Steve260Z74

If it is a 240Z, look here: https://fiddlingwithzcars.wordpress....cuit-analysis/
If it is a 260Z or 280Z, look at the BE section of the FSM. Those manuals give detailed breakouts of the different lighting circuits.

beg3yrs

Based on a quick scan of Doug's other posts, I think he's got a 280Z.

Sure would be nice if he came back and said something ...

Doug Horvath

hi guys,,, so very cool of you to respond so quickly .. yes the car is a 76 280z 2/2. kinda weird in that the combo switch was a bit messed up when I got the car , you had to flip it a few times now and then to get the lights to come on although the parking lights always came on. then it got stuck a bit and I gave it a bit of a push then it went on... but the next time I tried to turn it on I got no parking or dash lights but the head lights did come on... so I checked all the fuses and yes I did check them at the holders not just the fuses and then decided to take out the combo switch and check it out. I had a z where the turn switch went out and this affected the brake lights... anyway the combo switch had one of the spring loaded detents little nylon tips missing , tried to reman the switch but not too good... I was able to get the headlights to come on but still not the park... but I could jump between the RW wire and the small one next to it and the park lights would work... but still no hazard or brake... I pulled off the wires from the brake switch and found no juice the found the wire that goes to the lights in the rear and sent a power wire to the other one hence when the pedal is pushed it would work the brake lights... but no power to the line side of the switch on the stock wire... yet the fuse is good... when I turn on the hazard light switch on the console the turn signals stop working also... yikes I was on a job and had to stay late into the dark today and had to jump the mess to turn on the park lights ..... when I did I got a bit of a spark from the case and then the lights just stayed on so I unplugged the whole thing,.,.,. then when I plugged it back in I had no power to the lights at all at the combo switch so I had to pull the wires off the combo switch and send direct power to them just to get home... what a mess.... I know the combo switch is dead and needs replaced but wtf w/ the brake/hazard lights...

Doug Horvath

by the way I just love this car I also have a 94 stang convert and a 66 stang resto that is built a bit but I like driving the z .. I had a 240 years ago and I like this 2/2 better in that is has lots of room and seems to sit on the road better in corners yet the size doesn't seem to effect the power ... I put a true Carter AFB on it from a 421 65 Pontiac at 575 cfm on a custom built adapter .,,, lots of fun so there's the situation I'd hate to mickey the wiring in the car so any help w/ where I might find the power loss ... thanks dj

Skully

Do you have power to; horn, dome lamp, defogger? Power to all of these is on the same circuit in the fuse panel, which is supplied by a wire that goes to the fusible links. Since you know lights work when providing direct power, and fuse is good, then the supply to fuse must be messed up. Check fusible links. The reason you have no turn signals when you turn on the hazard switch, is because the way switch works; When switch is "ON", the power connects from the hazard flasher, which is always live, and feeds into your turn signals left and right, and disables the turn signal flasher. When switch is "OFF", the power goes to the turn signal flasher and disables the hazard flasher. All of this is tied into the "Alternator" fusible link.

beg3yrs

Skully brings up a good point here. Did you check the fuse for voltage or did you measure the resistance? If you got +12V at both sides of the fuse you're OK but it sort of sounds like you don't.

BTW, when I was reassembling my 260Z I found that those connectors at the junction block in the passenger footwell sometimes need an extra push to make good contact.

Doug Horvath

oh you guys are on it.... yes I do have power to the dome light,,, haven't checked the horn because it never worked anyway,,, and I don't know about the defogger in that I have not tried turning it on... it does not work due to breaks in the wires on the window..... I used a light to check out fuses... why would one have different volts at the ends of the fuses??? off to work now talk w/ you this evening.... thanks for all the help... Doug

beg3yrs

You should not have different volts at the ends of the fuses if things are OK. However, if you do, you've got either a bad fuse or dirty connections at the fuse. It needs to be noted that your test should be done with some kind of load on that fuse, i.e. one of the circuits the fuse protects should be activated. That could be a light turned on, radio or whatever. It's an Ohm's Law thing. If no current is flowing, there won't be any indication that there's a resistance in the fuse or its connectors.

Doug Horvath

oh yes of course... as an electrician I guess that should be obvious... duh... I do have power to the defogger ,,, haven't been able to ck out anything else yet just got home from work so..... I let you know what I find next... thanks again... Doug