Headlight problem and important info for 16v owners!

[JD159]

So! I think i got my lifter noise sorted out. Changed them all, removed the reground cams as an engine builder said they were doing more harm than good, had the scored journals massaged a little bit, and most importantly....

Cleaned the pressure reducing valve INSIDE the cylinder head and changed the o-rings. 16v owners, this is a MUST!

This was/has been the cause of my lifter noise and clearly why my cams and lifters were damaged after I purchased this rebuilt head from LINDSEY RACING.

THEY DID NOT CHANGE OR INSPECT THIS VALVE! Please make sure to change the o-rings or you are losing pressure throughout your entire head. The o-rings were so brittle the just snapped right off.

Anyway...

After I got everything back together, my headlights aren't working Not the motor, the actual lights. The high beams work great though, same with all the other lights. Last year I installed the Rennbay wiring harness with the relays so I don't think it is that...

How do I test the electrical system? I have a multi-meter, but not exactly sure how to use it to test for that. I searched and found that people test to see if there is 12v at the fuse, 12v at the switch 12v at the light, but I need some direction on HOW to go about testing everything, and where to start.

Anybody???

[DannoXYZ]

Test electrical system in segments along the way. I assume the Rennbay kit is similar to IceShark's with taking power from alternator and using relays triggered by the stock headlight wiring?

1. Check fuses
2. Test for power from stock headlight wires that trigger relay for low-beams
3. Test for power at relay-end of cable from alternator
4. Test for power at relay-outlet after being triggered ON by factory low-beam wire (step 2)
5. Test for power at low-beam bulb connector

If you have power at the bulb connector, but the bulb's not lighting, then all wiring is Ok, bad bulb.

[thomasryan]

Clark's


Click on the manual list. (Second listing on the left of the page) and go to body05 for the headlight motor circuits.

[djnolan]

Originally Posted by JD159

and most importantly....

Cleaned the pressure reducing valve INSIDE the cylinder head and changed the o-rings. 16v owners, this is a MUST!

Interesting, never heard of it, does it also provide oil to the chain tensioner? I suppose the S2 also has one?

[JD159]

Originally Posted by djnolan

Interesting, never heard of it, does it also provide oil to the chain tensioner? I suppose the S2 also has one?

It serves two functions

1) Prevent oil from draining out of the head when the car is turned off

2) Prevent oil from getting TO the head until sufficient pressure is built. It feeds the oil galleys that surround the head. Oil passes through this thing first! Super important and a must change. The o-rings will surely be dead and your oil flow will be suffering in the head.

[Pauld_94S2]

Check the headlight connectors that are just underneath the buckets that rotate down to raise the headlights.

The connector is about an inch in diameter and about two inches long.

They get intermittent.

You can get to them when the headlights are on and raised up.

[JD159]

Originally Posted by DannoXYZ

Test electrical system in segments along the way. I assume the Rennbay kit is similar to IceShark's with taking power from alternator and using relays triggered by the stock headlight wiring?

1. Check fuses
2. Test for power from stock headlight wires that trigger relay for low-beams
3. Test for power at relay-end of cable from alternator
4. Test for power at relay-outlet after being triggered ON by factory low-beam wire (step 2)
5. Test for power at low-beam bulb connector

If you have power at the bulb connector, but the bulb's not lighting, then all wiring is Ok, bad bulb.

I want to give this a try but I'm not entirely sure how to use the MM to check for this. Do I unplug it and just stick the probes into the sockets? I need a little bit more detail if possible

[JD159]

Ok so this is how I have my meter set. I pulled out the high beam fuse to see if I know what I'm doing. I pulled the steering wheel stock to activate the highbeams (didn't turn on because fuse 20 and 21 removed)

I put the negative lead to the chassis and touched the positive lead to the metal part on the fuse box for 20 and 21. Meter didn't read anything.

What am I missing??

[thomasryan]

is your key turned to run when you check the lights?

[JD159]

Originally Posted by thomasryan

is your key turned to run when you check the lights?

Yup!

What am I doing wrong??

Here I pulled the left turn signal front fuse and wanted to see if I could get my meters to read what I am supposed to. I'm clearly putting something where I'm not supposed to

[JD159]

Update! Wasn't inserting the probe far enough into the fuse hole.

Fuse 22 and 23 both have power!!!

What does this mean? Relay on the new harness????

[Rasta Monsta]

Originally Posted by JD159

16v owners, this is a MUST!

Is this part on all twin cams?

[JD159]

Originally Posted by Rasta Monsta

Is this part on all twin cams?

I believe all 16v 944 owners. Not 968. Pop the valve cover and take a look. It only takes a half hour to do the entire procedure.

[DannoXYZ]

Originally Posted by JD159

Update! Wasn't inserting the probe far enough into the fuse hole.

Fuse 22 and 23 both have power!!!

What does this mean? Relay on the new harness????

ok, good progress. Now move along the circuit to the next junction. Find the 3-wire factory headlight wiring on the other end behind the headlights. The original plugs should still be there. Check for ground, low & hi-beam power at those plugs. Most likely Ok, so let's move onto the new harness.

1. Test the new harness for power feeding the relay #30 terminal.

2. Test that the relay-coil ground is actually connected to chassis ground.

3. Test for +12v power on relay-coil from factory harness when you turn lights on.

4. Test for power-output from relay when activated, #87 terminal most likely.

5. Test that power from relay makes it to the headlight socket.

Here's good article on headlight relay harnesses and how they're wired up along with a clear schematic: Daniel Stern Lighting Consultancy and Supply

[JD159]

FIXED.

Relay on new harness corroded...

Luckily harness is still good as I swapped relays and the low beams worked and high beams failed.

Will relocate harness and buy a new relay!

CLOSED

[DannoXYZ]

Was it the relay contacts that were corroded? Or the relay itself internally? I used another vendor's headlight harness that comes with sealed waterproof relay & sockets. Such as this one: Amazon - ZFE waterproof relay & socket.


Wouldn't be too difficult to integrate that into your existing headlight harness.