S13 Sr20det wont turn over.

[LoganDavenport]

Hello guys this is coming up on a 1 1/2 year issue.
I can not, for the life of me get my sr to turn over with the key. When I say with the key i mean exactly that...I am pretty sure its a signal issue to the starter because if i un-clip the connector that sends signal to the starter and run a hot wire to the positive side of the battery the motor turns over. Great, so now we all know what the problem is right, fix that? WRONG. I don't believe that the wiring is in any way messed up. The engine harnesses are both Wiring Specialties products, the ignition is also new. The neutral safety switch has been bypassed, (also replaced beforehand) and Ive grounded, re-sanded the contact points on all grounds, within an INCH OF MY LIFE. I apologize for this post but i have done plenty of searching seeing as Ive had this issue for over a year now. I've been dilligently building this car and putting my money into it and i just want it to work properly. I am at my wits end and need some help. Also this motor was installed in a completely different shell, and the SAME EXACT ISSUE was happening...I am 100% stumped..

ECU not sending signal to the starter is my last guess...other than that i have no idea. I have tried absolutely everything I have seen on every forum, and been through the FSM at least 5 times trying to figure this out (so please do not link it to me) I searched, and waited over a year to post this...can anyone help?:ugh:

[wawazat8402]

The ecu doesn't have anything to do with the start circuit other than the orange wire that tells it to use the cranking map.

Also, was this originally an auto shell or manual shell? If it was originally manual trans, you need to bypass the clutch interlock switch not the neutral safety switch. It's a large relay with 2 connectors in the front passenger corner of the engine bay by the neck for the washer bottle.

If that's what you meant and it has already been done, I would start at the start position contact on the ignition switch and chase the signal along the chassis harness until you know longer see voltage. Sometimes these seemingly simple circuits are tedious as he'll to troubleshoot as you are definitely finding out after 18 months.

[240pimp]

Have you checked the circuit with a tester? When you turn the key, is there voltage getting to the solenoid to tell it to engage the starter? If no juice, you need to follow the circuit back to the key, test every part of the circuit, could even be a bad key cylinder, or a bad connection if you replaced it. Have you tested that the cylinder is sending juice towards the solenoid when the key is turned? The test meter is your best friend here. Ps- stop guessing and start testing.

How are your grounds?

Have you checked the fuse? I got lazy one time and tried to hook up the starter without disconnecting the battery in the trunk. Blew the 75A fuse, which is only available from nissan. Special order of course. What a pain the ass that was!



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[240pimp]

Sorry, it was the alt that i blew a fuze on. Cant remember if the starter is fuzed at the moment


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[LoganDavenport]

The ecu doesn't have anything to do with the start circuit other than the orange wire that tells it to use the cranking map.

Also, was this originally an auto shell or manual shell? If it was originally manual trans, you need to bypass the clutch interlock switch not the neutral safety switch. It's a large relay with 2 connectors in the front passenger corner of the engine bay by the neck for the washer bottle.

If that's what you meant and it has already been done, I would start at the start position contact on the ignition switch and chase the signal along the chassis harness until you know longer see voltage. Sometimes these seemingly simple circuits are tedious as he'll to troubleshoot as you are definitely finding out after 18 months.

Thank you so much for your reply. I believe it was a 5spd car, as with my other shell that the motor was previously in. The only thing i bypassed was the thing above the clutch inside the car. When i get home i will try to locate the clutch interlock switch. Will update if it helps, and i suppose i will try to trace it down once again. Although this is getting really frustrating because I've done so at least 3 times. Im sure whatever is wrong is so simply i will want to just die but i am determined to find it.


Also, when i do turn the key, if i have a buddy standing in front of the engine bay you can hear relays in both fuse boxes clicking, is this normal? Once again im sure its something to do with signaling because i have tested and im getting power to the starter with the key on, and when you move to the signal connector (the one that isn't held down by a bolt) it gets power in the on position of the key, but in the start position nothing. And if you run a wire directly from that location to the positive side of the battery, while the key is in the on position the car starts.

[LoganDavenport]

Have you checked the circuit with a tester? When you turn the key, is there voltage getting to the solenoid to tell it to engage the starter? If no juice, you need to follow the circuit back to the key, test every part of the circuit, could even be a bad key cylinder, or a bad connection if you replaced it. Have you tested that the cylinder is sending juice towards the solenoid when the key is turned? The test meter is your best friend here. Ps- stop guessing and start testing.

How are your grounds?

Have you checked the fuse? I got lazy one time and tried to hook up the starter without disconnecting the battery in the trunk. Blew the 75A fuse, which is only available from nissan. Special order of course. What a pain the ass that was!



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Power wire on the starter is getting juice in both positions, signal wire is getting juice in on position but not in start position, i have a test meter and i have traced the wiring but its very possible i over looked something.

"Key cylinder" is new from Nissan and is in working order.

As said in original post I have made sure every single ground is connected and making good contact. I'm 100% sure that the only ground that is un connected is the one by the brake master cylinder. But it will be re attached once I finish putting in my brake booster and 300zx master cylinder.

I haven't been lazy :-/ I am just not very good with tracing down electrical problems and wiring problems. I'm trying to get better at it and feel bad for bugging people online for answers to my problem but i am fed up with it and considering just buying a button to wire to my signal connection on my starter and do it like that. (although I would prefer to have it wired properly)

[LoganDavenport]

WAIT, is there a clutch interlock switch above the clutch pedal (i already have that bypassed) but is there also relays located in the passenger side of the engine bay, left side of the battery? because i have a couple of plugs that arent connected to anything there....are some of those supposed to connect to two blue relays attached to a mounting bracket? because im sure those are missing on this car, and i remember taking them off my other car? "clutch interlock relays" if the switch is bypassed and the relays are missing could this be my problem?? i will feel so damn retarded..

[wawazat8402]

If you have the relay under the hood connected, bypassing the one on the pedal will work. If you bypass the one under the hood it doesn't care what the switch on the pedal is doing.

Below is a picture of the connector under the hood after the large blue relay has been bypassed. The wires going to the left tie into the chassis and are untouched. I found a mating connector with the same wire colors and gauge. To the right the b/w and b/y wires are crimped together and heat shrink covers the end. Makes it easily removable as an extra layer of security if you park the car somewhere.

http://i22.photobucket.com/albums/b342/wawazat8402/Coupe%20Build/7BDF91C6-5D99-4D77-97B7-CC48A019559C_zpshvshoapm.jpg

[LoganDavenport]

If you have the relay under the hood connected, bypassing the one on the pedal will work. If you bypass the one under the hood it doesn't care what the switch on the pedal is doing.

Below is a picture of the connector under the hood after the large blue relay has been bypassed. The wires going to the left tie into the chassis and are untouched. I found a mating connector with the same wire colors and gauge. To the right the b/w and b/y wires are crimped together and heat shrink covers the end. Makes it easily removable as an extra layer of security if you park the car somewhere.

http://i22.photobucket.com/albums/b342/wawazat8402/Coupe%20Build/7BDF91C6-5D99-4D77-97B7-CC48A019559C_zpshvshoapm.jpg
Right, I am saying the one in the car is bypassed, but the relay is missing completely IIRC ill check when i get home but if i have the one in the cabin bypassed but not by the battery, its missing IIRC

[wawazat8402]

I'd bypass the one under the hood. It removes one more needless component that can fail and leave you stuck push starting the car. The wires I pictured just need to be connected together, you don't have to include the connectors like I did above.

[LoganDavenport]

I'd bypass the one under the hood. It removes one more needless component that can fail and leave you stuck push starting the car. The wires I pictured just need to be connected together, you don't have to include the connectors like I did above.
My question was if that relay is missing completely and the connectors that connect into it are left un connected, but the switch (above the clutch pedal) is bypassed...Will the car still not start?

[wawazat8402]

That's what I was explaining post before last. If the relay isn't there and those two wires aren't joint, the switch on the clutch pedal won't be triggering anything. Your method of bypass only works if the relay is there. Bypassing the relay works no matter what you have or have not bypassed on the clutch pedal.

[LoganDavenport]

I'd bypass the one under the hood. It removes one more needless component that can fail and leave you stuck push starting the car. The wires I pictured just need to be connected together, you don't have to include the connectors like I did above.
That's probably most likely my problem then. Will bypass the relay when I get home and update tomorrow.

[LoganDavenport]

So its all fixed thank you so much that was the problem. I feel like an idiot bit I am so relieved!

[wawazat8402]

Glad it's fixed. The problems that take forever to find are normally little things. If it was something huge you'd have seen it right off the bat.

[LoganDavenport]

Glad it's fixed. The problems that take forever to find are normally little things. If it was something huge you'd have seen it right off the bat.
Very true. This is such a relief, I know I should have checked that but I figured since the switch was bypassed I ruled that out. But lesson learned!