Turn signal kills engine

[Butch280z]

Whenever I switch my Z into reverse or try to use my turn signal it will kill the engine, as a result it has become nearly undrivable. Has anyone else ever had this problem? If so, please include your solution. Thank you.

[seattlejester]

Welcome to the forums, note this should really be in the troubleshoot section. 

 

Will the car run if you don't use reverse or the turn signals?

 

If shifting into reverse or using the turn signal kills the engine, it sounds like an electrical problem. The lights that correspond to the wires should be on a separate fuse, so if they were grounding prematurely it should be blowing a fuse not killing the engine. Without a multi-meter this will be a difficult problem to address. If you could get readings of your battery that would be helpful in removing that as a problem source. If your battery is old or low on charge, the turn signal or putting it in reverse could drain enough power from the system to not charge the coil, killing the engine. I would suspect either the wiring for the turn signals, the turn signal switch itself having a burned contact, or the turn signal flashers, but throwing in the reverse lights makes me lean more towards a short causing the battery to drain.

 

Additional information to the problem at hand would be beneficial as well. Such as the year of the car, any recent changes, basic electrical checks (alternator-load test/battery-voltage, fuse box condition).

[Butch280z]

Thank you for the welcome, and I'm sorry, I forgot to include that it is a 78 280z and yes, it will run and drive, but the turn signal and going into reverse will kill it even with a full battery, I have a multimeter as well, and I forgot to include that *sometimes* the turn signals will work, but if I restart the car, they will not work again, it seems to almost be at random.

[Butch280z]

And is there a way I could move this to the troubleshooting section without double posting?

[seattlejester]

I think a mod may move it unless they deem it is related enough to the forum location to remain here.

 

Hmm, I hate to ask, but is the battery fully charged? A drain could kill a battery quite quickly, granted if the battery was killed the car wouldn't start up right away again. 

 

From my limited thoughts, I would check the voltage while the car is running and then turn on the turn signal to see if there is any differentiation in the voltage when it goes on. 

 

If it is not the battery and it is linked with the reverse switch or turn signals it points towards an electrical fault, which would mean referring to the factory service manual (available online) and tracing the wires for the ignition and the turn signal and seeing if they cross somewhere or are shorting into each other. The wires do share the same harness from the steering column all the way to the front of the vehicle so it will be quite a bit of wiring to check. I would start at the ends though, at the steering column and the switches and at the coil/igniter/turn signals. Both are known to be fault points in early z-cars not so sure on the later models.

[zohanisback]

Hmmm.... I'm thinking signals and reverse light causes ignition fault and kills coil voltage? It wouldn't be a fault to ground, it would be an open circuit fault, I think it what they call it? You can effectively narrow this down (hopefully), to the steering column area and anywhere the reverse light lights intersect with the turn signal switch and relay.  Should only be a half dozen spots or so.

 

Either way, this one is gonna suck... 

Edited June 26, 2013 by zohanisback

[seattlejester]

That's what I would imagine, but the reverse light is what throws me off.

[xonix_digital]

I had some crazy electrical issues with regards to my turn signals too.

If you unplug the directional relay does it still turn off the motor when the turn signal switch is activated?

 

My issue turned out that two wires I had plugged in from the ignition/combo/directional switch harnesses switched and plugged into the wrong wires.

 

Just a thought.

[Pharaohabq]

Hmm 78, Did you do any work, make any kind of changes to the car, or did this just start happening all the sudden? 

 

I'm really wondering why you're not blowing fuses.  First thing you should check all your grounds, then check the wiring in the hatch area, and then everywhere the wiring goes through the firewall.  it really sounds to me like a wire is shorting somewhere. Possibly between the turn signals and the coil signal wire.  An "Open" would not allow the car to run. Possibly the coil power is being shorted.

 

Now this doesn't have to be in the engine compartment.  The car, when running has the key in the Run position, this energizes the key on power, and provides power to the coil. If something shorts that "key on" power, or it cuts power to that line, the car will die. Since you're not getting burning wires and blown fuses, I'm thinking that line (if I remember it's white w/ red stripe) is losing connection when the blinkers/reverse is powered.  Reverse as he said above, is the enigma, since it works off the reverse switch on the tranny, and runs back to the separate reverse lights, and nowhere near the combo switch. That's why I'm thinking the issue is with the "Key on" power, but perhaps not in the combo switch.

[braydon84]

Hahahaha old thread revival time. I'm having this EXACT same issue on my 78 280Z and I'm losing my mind trying to figure it out. The following parts are all new and I'm still having the problem. ECU, injectors, fuel pump, fuel filter, fusible link, turn signal cluster (not sure what the actual name for this is), ignition, coil, starter, distributor...and basically a whole new top end minus the cam and valves.

 

I purchased a reverse switch but haven't put it in yet. My car used to make a clicking sound from the fuse box area but now it won't turn on at all. Engine turns over but nothing electrical works.

[NewZed]

I would start a new thread in the Troubleshooting section, as suggested to the first guy, and describe in detail what your problem is.  Why add to a thread that's already in the wrong place?  Your engine doesn't even start now, so not really EXACTLY the the same.  Add details like automatic or manual, how many circuits you've checked with your meter, whether or not any fuses have blown, condition of fusible links, etc.  The basic stuff.  Add whether or not it's ever run, how well it did if it did, and when the problem showed up.  There's not much to work with in your post.

 

You can check the reverse switch by disconnecting it also.  No need to install a new one until you check the electrical.

[MaritimeRiceburn]

If I recall correctly the reverse lights and ignition both use the same ground to the wiper motor. Also all of the tail lights as well as the dome light take power from the steering lock switch. All of these should be located on or go through the steering column, which has several matching connectors with differing functions.

 

Have you played around with your combo switch lately? You may have accidentally interchanged some plugs. 

 

I know my 72 had an issue where the PO plugged a headlight into a turn signal.

[FLC]

I would check the condition of the switchs and harness on your column including your horn switch. Have you tried replicating the fault at different steering wheel positions while wiggling it. Taking the switches apart and cleaning them isn't too difficult. That would be a good place to start.

[Usain_Boat]

This thread is obviously very dead, just posting to hopefully help someone that may encounter the same problem as this comes up when you search for "Turn signals kill engine 280z". I was recently having this problem and have a thread tracking it down on ClassicZCar too.

The problem in my specific case was that the crimp for the White wire that provides power to the fusible link that protects the whole fuel pump, reverse lights, and turn signal system was corroded and fell apart when I peeled the electrical tape.

 

Anyway, I hope I can help someone find the source of their problems or at least bring this dead thread to a decent conclusion.

 

Also, at least for my '78 280z the fusible link block that appears to b in the front on the wiring diagram is actually in the rear.