Honda D Series Forum banner

possible kill switch with relay

500 Views 7 Replies 3 Participants Last post by  jacksonkitchen37
i am working on a 99 civic ex. just finished with overhaul and it refuses to start. Posting with pics. i have checked all fuses and relays in car and underhood. proper reading at coil and at distributor main connection. However it has no spark to 1-4. All engine grounds are clean and tight and injectors have power and signal. timing is correct. this is a salvage vehicle and pretty positive the kid is trying to screw me on the bill as he came by to grab some things but never retrieved anything, almost immediately afterwards started calling to come take his car to another mechanic. Please help as I have alot of money invovled at this piont,. ok so the pics, sorry they are blurry and lighting is horrible. This is what i have traced back to under dash on steering colom. The relay has a diode (i believe) between 85 n 86. 30 is a 12 guage red, 85 is orange and like a 24 guage wire along with 86 which is blue and 87 is not used and 87a is white 12 guage. the white wire (87a) is spliced in between the black with white strip wire and the orange (85) and blue (86) wire lead up to the somewhere behind the instrument cluster and the red wire (30) on looks to be the white with red stripe coming off the obd connector. appreciate yalls input as this has me stumped. Also changed the coil with brand new and distributor cap and rotor. thanks guys look forward to hearing what comes of this. This car is due back tomorrow and need conformation or what it actually is before i put my business on the line with an accusation. thank again. im kitchen by the way. lonely garage mechanic.

Electricity Gas Cable Electrical wiring Wire

Electricity Electrical wiring Cable Gas Automotive lighting

Electricity Electrical wiring Line Cable Gas

Automotive lighting Automotive tire Automotive design Motor vehicle Vehicle door

Automotive lighting Finger Gadget Audio equipment Headlamp

Hood Automotive lighting Motor vehicle Automotive tire Vehicle

Automotive lighting Hood Electricity Electrical wiring Automotive design
See less See more
1 - 8 of 8 Posts
Is the fuel pump getting power? Main relay is a usual suspect in these cars, does fuel pump come in? Over the internet diag is difficult.
I'd also check clutch safely
That looks like the cheap starter kill circuit installed by many low end dealers, usually activated by holding the headlight stalk switch in the highbeam flash position when turning the key to start. Pretty easy to defeat with 2 spade terminals and a jumperwire between the larger gauge wires with the relay removed.
The ICM may be bad, so grab a test light, remove the distributor cap, clip the test light to batt+, touch the probe to coil negative, crank the engine and watch to see if the test light flashes, this will tell you if the ecu and ignition control module is grounding/ungrounding the coil to produce spark.
Ok Georgia EG and Oldcivicjoe this should answer all your questions, yes fuel pump has power but would run full throttle lol as soon as the key would turn to car on engine off position 2 i believe. no spark on 1-4 from distributor to plugs. So naturally I went toward the distributor coil and ignitor which has always been an issue with honda engines. Seemed logical. Then I noticed that this distributor had no blue and black w/yellow stripe wire for the tach output. This is the reason for the relay under the dash. The relay is hooked to the tach so first thing came to mind was a ignition kill switch through relay. Looked like i was on right track at this point. Everything is adding up especially when I came across the relay under dash OldcivicJoe. I literally have tested almost every system on this civic from injectors to ignition to security system every possible sensor and ohmed wiring out for shorts or opens. WTF at this point, right? So as any mechanic would do I start from the beginning and retrace all work I have done and verified proper installation and then moved on to the engine compartment and harness. Then it dawned on me. When testing the injectors you should get 12v across both pins. When grounded the injectors will pulse on and off. No go they stayed 12v solid while cranking or just ignition on no run. Has to be an open ground. As soon as I realized that my injectors were not operating, fuel pump constant power and no spark to my plugs and everything else checks and balances there was no doubt I was missing a freaking ground (s). So my conclusion is this. The injectors must have a negative or ground to operate along with 12v constant. Spark plugs must have a ground to the cylinder head or block.along with the valve cover or no spark even though you may have power at the harness side connector. Distributor, coil and ignitor all checked out. So while searching and testing and cussing I remebered seeing the ground ring terminal and one was broken. Didnt see the end of bare wire so I connected to thermo housing and moved on assuming that the brown wires were spliced into the black wire under the tape and loom. My dumb ass fualt there. Lessoned learnt. I stll am cleaning some stuff up and then going back out to retest for spark and injector cycle. Since I connected the grounds though correctly the fuel pump primes for 2-3 seconds and is standbye. All running ligjhts and interior lights and dash lighhts, radio, etc. are operational. At this point it looks like I solved it with the help of awesome and knowlagable members. I will post an update ijn couple hrs after I verify my timing for the 29th time and crank her up. Thanks guys for the help as hard as it may be to diagnose over internet GeargiaEG, if we get good at the hard shit then the rest of life is no comparison.
See less See more
  • Like
Reactions: 1
Those pesky thermostat grounds are where the ecu grounds the injector drivers and where the icm grounds the coil, been a bane to many at one point or another.
your telling me. I was beginning to start thinking i had seriously overlooked something that was more serious as in head gasket not seated properly or loss of compression after rebuild even midadjusting valves and decarbonizing the head. Then realized that still wouldnt explain the no spark even though it would have explained a no start issue. Thanks for the help as this is the strength of community and sharing knowledge. They can never take away our knowledge for they no not the depths at which it flows.will keep yall updated. Headed back out to finish some installs that are lingering then turning the key
Awesome, please post the conclusion if it's sorted or even if not, the bane of everything is not having complete info, and if it's solved don't forget to apologize to the guy for thinking he was trying to force carnal knowledge on ya🤣
Lmao. Absolutely will post here directly the results. Couple loose ends to situate then one of two options. We will find out for sure or we start diagnosing next issue which is more normal than not. Engine rewire in the near future.
1 - 8 of 8 Posts