Electrical Gurus & Starting Interlock Relay

[Occams_Razor]

Hi Guys,

I am a certified A&P so I am more than vaguely familiar with the ways of the electrical gremlins but this issue has me stumped.

Little background.

I have one of the few 02M 6 speed MKIV's in the US. I imported the transmission from Germany and installed it myself with all new parts swapping out a 01M auto trans.

I DID NOT convert the wiring harness from my auto as detailed in Alphaseinor excellent Project Kill Da Auto Wabbit!, Or how I learned to love the Manual Swap thread. I lucked out and got a NOS complete manual tranny harness from a gentleman who was converting a 1.8T and bought the wrong harness and I installed that OEM harness to completely replace the auto trans one.

All of that preamble out of the way here is my issue.

I have been having a problem where the starter will not energize. The Starting Interlock Relay does not activate to provide current to the starter circuit.

Here is a picture of the offending circuit.

I thought I might have a bad relay so I bought a new one from Impex. When I installed it I got nothing. Not even a click. I moved the horn relay, (another factory 53 relay), over to the Starting Interlock position and still nothing.

The wiring appears to be correct in the car but a stock relay "53" will not work.

The only relay I have been able to get to work is a generic, fused Hella relay part number 003 510-36. (Turned out the 15 amp fuse had blown but I would still like to get the wiring correct.)

Here is a picture of the wiring diagram on the side of the Hella relay and the pin outs.

If I install the brand new replacement relay, (part number 4H0 951 253 A bought from Impex and verified as correct in ETKA), I get no joy.

Here is a picture of the wiring diagram on the side of the new stock 53 relay and the pin outs.

So that is where I stand. Something is screwy but I am not quite able to put my finger on what.

Any help would be appreciated.

 

[Plus 3 Golfer]

It's pretty obvious that the plug connectors on the Hela relay for the coil are (85, 86) since you say that the Hela relay works. These plugs correspond to plugs (2,3) on the "supposed" correct relay. 2,3 according to your diagram for the "supposed" correct relay is NOT the coil. Therefore, I'd say you do not have the correct replacement relay. Also, I note that the wiring diagram shows the plugs on a correct relay should be labeled 2,4,6, and 8.

 

[Occams_Razor]

It's pretty obvious that the plug connectors on the Hela relay for the coil are (85, 86) since you say that the Hela relay works. These plugs correspond to plugs (2,3) on the "supposed" correct relay. 2,3 according to your diagram for the "supposed" correct relay is NOT the coil. Therefore, I'd say you do not have the correct replacement relay. Also, I note that the wiring diagram shows the plugs on a correct relay should be labeled 2,4,6, and 8.

Had never noticed the 2,4,6,8 mismatch but the relay is the correct one according to ETKA. 8K0 951 253 has been replaced by 4H0 951 253A which is what I have.

 

[Plus 3 Golfer]

Are the starter interlock circuits are the same for a manual vs. auto but for the clutch and neutral switch? I don't have access to ETKA or a Bentleys for a Jetta to check the differences in the starter interlock circuit and relays for a manual vs auto.

 

[greekdubber]

why dont you just delete it?....The ROW VW's with manual transmissions don't use it only automatics and I removed mines just a thought,it's more less a DOT safety switch for manual NA cars.

 

[Occams_Razor]

why dont you just delete it?....The ROW VW's with manual transmissions don't use it only automatics and I removed mines just a thought,it's more less a DOT safety switch for manual NA cars.

Tell you the truth I never really thought about it and when I was installing the clutch pedal from the German PD150 that I got it from it didn't even have the lever on the top to actuate the clutch pedal switch. I questioned it at the time and then just blindly got another NA pedal with the lever and installed that, (turned out to be a pain to swap out too!).

I learned how to drive on an old 1971 Super Beetle and I always check neutral and push in the clutch from the force of 30 years of habit. I don't think I will have a problem with it now.

Thanks for pointing me to the one solution that is simpler and therefore the "better & more profitable one." (With an avatar of Occam's Razor you can color me embarrassed... )

 

[greekdubber]

Tell you the truth I never really thought about it and when I was installing the clutch pedal from the German PD150 that I got it from it didn't even have the lever on the top to actuate the clutch pedal switch. I questioned it at the time and then just blindly got another NA pedal with the lever and installed that, (turned out to be a pain to swap out too!).

I learned how to drive on an old 1971 Super Beetle and I always check neutral and push in the clutch from the force of 30 years of habit. I don't think I will have a problem with it now.

Thanks for pointing me to the one solution that is simpler and therefore the "better & more profitable one." (With an avatar of Occam's Razor you can color me embarrassed... )

lol no worries I enjoy not having mines

 

[compu_85]

The clutch interlock has been broken on my car for over 5 years. I don't miss it

If you did want to hook it up:
30 & 86 go to the start position on the ignition switch
87 goes to the starter solenoid
85 goes to the clutch fully depressed switch (other side of the switch goes to ground)

Why not just have 86 go to constant +12? If you connect it up that way the relay will click on every time you shift... annoying. Hooking it up to the start terminal on the ignition switch means it will only click when the key is turned and the clutch is pressed.

-J

 

[graeme86]

The stock relay also has a resistor across the coil to stop voltage spikes, but that should not have affected its operation compared to your aftermarket relay you used.

Very strange.

Just delete the whole thing - our manuals don't have them over here either.

One less thing to leave you stranded somewhere.

We just have a two pin switch for the cruise control system on the clutch pedal though.

 

[Occams_Razor]

Just delete the whole thing - our manuals don't have them over here either.

One less thing to leave you stranded somewhere.

I less thing to leave me stranded.... Twice...

All fixed now.

We just have a two pin switch for the cruise control system on the clutch pedal though.

That bugger is disconnected because it keeps throwing a code that annoys the heck out of me. Haven't had time to play with it.