Nick, can you take another picture, but this time more in the direction of the red arrow in the attached jpg. Thank you.

Frankly it's been years since I've looked at that switch and I may have described its location wrong. Plus I'm too lazy to go look at my car right now.

 

The Image you posted of the Interlock switch in the FSM, I can't seem to find it under the dash...

Your arrow is pointing at the Clutch switch(pic in previous post). Which is the only switch I found on the clutch pedal assy.

 

This is the interlock switch on my '88. The other one you guys are looking at is for the cruise control. Nick, you don't have the interlock switch.

My interlock switch has been disabled since I bought the car 9 years ago, but my click-no start issue only developed after I turbo swapped the car (like Rob apparently). It's really strange that it picked that time to start acting up, since only the starter changed. I even changed it out in case that was the problem, but it wasn't. I've put off messing with the whole thing for awhile now, but I think I'll dig into it again tomorrow. I'd really prefer not to bypass the security relay, but I could do it for awhile just to test the theory.

 

The core of the problem is the Starter solenoid can't draw enought amps through the stock wiring (which goes from the battery, through the main fuse, through the ignition switch, through the interlock switch, throught the cut relay (or blue plug), and then finally to the starter solenoid) to close the circuit to engage the starter. Over time corrosion builds up at each of the connection points. One by itself shouldn't cause a problem, but all of those in total add up to the resistance preventing the needed amps to get through.

But that same wire certainly can provide enough amps to close a Bosch relay, thus why it at least remains a good source as the positive trigger wire. So running a heavy guage wire directly from the battery (thus avoiding all the amp reducing connections) through the one connection of the Bosch relay, the solenoid can now once again draw all the amps it could ever want.

I'm actually a believer in the safety aspect of the interlock swith keeping you from engaging the starter while the transmission is engaged. Thus why I did it the way I did.

On the Bosch relay pin 86 and 85 are where you connect the trigger + wire (Black/Green) and chassis ground respectively. The source wire from the battery (add a 30 amp fuse for safety) is connected to pin 30, and the wire to the solenoid (Black/White) goes to pin 87 (not 87a).

 

Thanks Hozzman, I'm going to give it a try. Will post up my results when I get it wired in. So tired of click, click click, click click, click. Wait, click click click, turn the key off. Try again click, click, click, grrr grr varoom.

 

thanks im thinking about doing this. Could possibly add a kill switch to the clutch switch for added sense of security as well?

 

Better alternative to that thought, add a simple on off switch to the fuel pump wiring (easy access under the dash right above your right leg when you're sitting in the driver seat). Installed mine on the side of the center console.

That way you get that added manual security, AND you can deflood your engine if you ever get a hot start situation without leaving your seat.

 

so what if it goes click click turns over slow, then starts normally?
cause that what my car started doing, and its really annoying. so any help would be nice.

 

The slow starter is about the starter not able to draw enough amps as well. Dirty battery posts, poor ground to the engine (supposed to be attached to the upper starter bolt), Corrosion between the starter wire at the battery or the connector at the starter.

Or, it could simply be your starter itself is simply crapping out on you.

 

I'll throw in my 2 cents. I JUST started having this problem. I've also had it in the past. It's got to be the weather! All winter long my car was turning immediately. It's a bit warmer now and I am starting to get these clicks. I just keep trying, obviously, until the car starts. It's odd though, usually the warmer weather makes the electrical gremlins go away. I don't know... maybe i'm a ray-tard

 

Unless those gremlins are due to electrical resistance, which is increased as temperature rises. If we could just make the wiring superconduct, this starter problem would go away. Anyone have a cheap source for LH2?

 

^in my case, warmer weather has made some of my electrics actually work better. Example for me were some things CPU related. My horn used to not work, nor did my lights on/door open beeping work. But when the weather got hotter, my horn would work, and if I open the door I get the beep beep with the keys in the ignition. I know it has to do with metal contacts and such expanding. My car is old, and it has probably 200k+ miles on it. The wiring has seen better days. Mine is a more extreme case of relation to ambient temperatures I suppose...

 

I've got a sticky starter too that I couldnt solve, good info, maybe it's this...!

 

So I took the idea a step further and retained the stock starter cut relay, but converted it to be the trigger for a second relay. The second relay draws power directly from the main fuse box. There's an extra slot on S4s, so I added a 30A fuse and pressed a spade connector into the stock plug underneath. Instant fused power with a stock look. I tested it a bunch tonight, and it started every time.

The advantage to my variation is that the alarm system can still cut power to the starter, which is something I really prefer to keep functional.

Here's the diagram & key. Note that the ignition switch wire is actually black/blue, but it's listed as black/green in the S4 FSM. This might be an '88 only thing, but I doubt it. It's probably a typo.

LG/Y: Alarm Control Unit
B/G: 12v
B/L: 12v (Ignition Switch)
B/W: Starter Solenoid

 

^ Excellent improvement. Today I redid my wiring to follow RotaryRocket88's example. Fires up great.

A clean place to do that is down by the starter. Trigger off the Black/White wire as indicated to 85. But the trick is you can source the direct power to 30 from the hot to the starter itself. Avoids extra wires from the batter itself, so a bit cleaner install.

Everything is in close proximity, so shouldn't take more than 30 minutes to complete the job.

 

get a new car or grounding kit lol S4 suck

 

It has nothing to do with S4s or grounding. S5s use the same exact ignition/starter setup, and the issue is with the POSITIVE side of the circuit.

 

Oh right, everytime I have any problems with my car I just buy a new one and Grounding kits fix all the factory wiring problems in a +20 year old car... duh!?

Good Idea JunPOwer, GTFO.

I'll be picking up a relay today or tomorrow, will post results with pics...

 

rotaryrocket88 you the man!

 

Definitely going to do this on the new car, even if it doesn't have the problem.

 

Thanks, but I've got to give Hozzman the credit for getting the ball rolling.

I'd been tolerating this problem for over a year. Now it's finally back to starting every single time. The other option I was toying with was just replacing sections of old wire, but that would have meant unraveling the harness, and it still would have had all the potential weak links in the circuit. Drawing power directly from the battery/fuse box over brand new wire is so much better.

I need to simplify my wiring a bit, then I'll post up some pictures. For now, I've just got a little harness & the extra relay tucked under the trailing coil.

 

************************************************** ************************************************** *************************************************

You might consider the ignition switch as the culprit. Just go to the ignition switch leads. Jumper the pure black wire to the Black/Red (start circuit wire), and see if the starter turns over each and every time you jumper those two wires. If it does turn the starter each time, then it seems to me that proves the ignition switch is the culprit. When you turn to START, that black wire (and ignition switch) is feeding not only the start circuit but also now powering up the IG1 buss in the interior fuse box. No key required doing the above.

Substituting in a relay from Rado Shack to the circuit will work for about three months. Then click, click again. Pull out that radio shack relay and put in a NEW one just like it and the click, click goes away once more. I'm suggesting a stouter relay than one from radio shack.

 

I have tried that and replaced the ignition switch with a new one. No go!!!! I have been working with hozzmanrx7 to fix the problem and found the issue. This is the correct fix.
Thanks Robert

 

Thread should be archived for future reference!

RotaryRocket88, is this "alarm control unit" in your diagram referring to the factory theft deterrent system?

 

Yes, that's the wire from the theft deterrent/alarm system.

My ignition switch is less than a year old. Bought a brand new one, and it changed nothing.

The relay that I'm using is rated for 60A, so I'm not too worried about it. Are you suggesting a particular kind of relay? A high-end brand or something?