C4 1990 Electrical Ccts FSM

[Vettech]

OK, found it, another obscure little diag on the net.
And the only buttons I did not press was the Radio, yes its the Amplifier relay, for the supa dupa Bose System, and the only section in my 87 book I did not look at was the Radio etc, and yes the wiring, type & colours are a match. Done!.

But before I put it back together c/w the Instruments, I'll just double check the pump operation & relay.

[sirfixalot]

 I find the colour codes on  wiring doesn't change from one year to another so the relay you can't identify you will probably be able to identify from 87 circuits, when i was reading your description of relay with yellow wiring i automatically thought of starter relay which you went on to identify. What colour are wires on relay you cant identify

[Vettech]

Thanks Sirfixalot. Got them all sussed out, the Start Enable Relay, the C68 AC Compressor Relay and the mysterious Bose Amp Relay.  Also my fuel relay and pump are OK, age and the higher level of padding and insulation prevented me hearing it run.

I filled the 2" hole in the vent ducting, now I get a good level of AC coming out the RH face vent. However other holes and ducting mismatches, once corrected will also increase the air flow. Once again I wish I had bought one of those optic fibre camera's, you know the ones you stick in tight places to see thing's. Between limited light, access and head cramped up under the dash, I think when they mounted the Steering etc (chain&bar), they ground/sliced a section out of the AC Fan housing body to clear the mounting bolts.
Upon running the AC - I can feel air and hear the fan, but can't see into the tight space, I'd hazzard a guess that there is a ~ 20mm hole or oval hole thats leaking air and most likely screwing up the fan's ability to operate at max efficiency.

I'm becoming an expert at using Black Silastic sealant, it amazing where you can stick it, paint it, plaster it to overcome the shortcomings of previous converters. I still have one small corrugated duct that feeds the vent directly under the steering wheel right between the drivers legs, the ................... cooler vent.

[Vettech]

Sirfixalot - question.
I'll try to get a pic up, but do you know what a three (3) pin plug with Black and a White with black stripe wires would go to.
It too is hanging under the RH steering column, I've paired up all moduls and plugs, the only other two wire plug is the Orange&White which I'm sure is for the foot well lighting.

Also armed with Dentist pick & a sneaky mirror on a stick I've proved there is a hole in the air box, which now has a piece of Corflute type material cut and pasted into place, blocking and sealing the hole. Its amazing how much more air comes out where it should once these mongrel holes are sealed up - soon it will be toooo cold in the drivers seat - heaven forbid !....

[sirfixalot]

Looks like it clips onto something sheet metal will have a look tonight first thing that came to mind was vats with 2 wires but plug is totally different, maybee key chime alarm  but that is normally incorporated into harmonica plug for blinker switch

[Vettech]

Another question.

Accelerator pedal has the spring loaded foot pad, but the whole pedal is pivoted further up where it bolts to the firewall.
Is there a spring meant to be in there ?, otherwise its just the weight of the lower half of the pedal that pulls the cable centre back.

Not sure I have this well thought out, but I know there is a heap of travel in the pedal before it even starts to pull the cable and start accelerating. And since we all know just how powerfull these little C4 babies really are, I feel I'm not getting maximin bang for my buck.

And yes you guessed it, the pedal is out of the car.
(Pedal also needs some metal removed as its interfering with other bits.)

[sirfixalot]

If the distance between the firewall and pedal isn't correct you will end up with slack before throttle starts to open you can slit a small piece of metal tube length wise and slip onto cable between ball end and pedal then close up with pliers, to make more responsive. I had a new cable made for RHD and had an adjuster put in cable between bracket and throttle body arm. If you change the pin on throttle body to a ball stud a holden HJ about 1300mm long will fit and is available on ebay.You also need to adjust TPS to get max voltage at wide open throttle,then adjust the auto kick down cable to suit, kick down will prevent WOT if not adjusted correctly. Cable pulls back from throttle body no spring on pedal

[Vettech]

Yep its not Vats, today I modified some towel rail approx 40mm long, some black Silastic,  and my last piece of ducting is jointed up very nicely, whilst checking, the car would not start, bloody hell what now, and a plug kept poking into my eye...... Ah! Plugged it back together, and after a wait car started, well at least Vats and the key resister etc are working Ok. (Its a very small 2 wire plug/socket).
Not the one I'm chasing though.

Started to rain again,  anyway the Silastic needs to set, save more for tomorrow, when I'll try the Instrument panel back into place, test for any issues, there are days stuck up under dashes that I wish I had the statue of a small brick laying person, they get it so easy!..
Regards.
P.S. have not re-installed the Pedal as one bolt is cross threaded, I wish Bunnings was open, although they dont sell individual dies or taps for that matter, maybe I'll sneak down to see the Wilton Oracle. Get my black balaclava on and run Blockades.

Oh and ........ "Goodbye  Glady's".... I'll miss you at the morning Covid19 updates (LOL)

[bfit]

Gladys for PM.
Bfit
Ps a year and a bit to next federal election, timeframe's about right.

[Vettech]

A Glady's one day, a Barilaro the next - we go thru Pollies like a dose of salts.

Anyway. Put the Instrument Cluster (IC) back in place along with enough other bits to allow power up and test.

Alas Grasshopper, we still have issues, the IC is a "plug in" arrangement (see below) the plug is set thru the main PCB, those little silver spots are the ends of the pins and plug into the socket which is captive in the base of the IC cradle. But the socket is proud of the back plane and SHOULD plug right thru the PCB, one glance at the arrangement smacks of potential problems. Once in, all systems came on, but whilst securing, lights etc started to flicker on and off, any pressure on the IC diametrically above the plug gave varying results, also any pressure up under the rear of the cradle behind the wires going to the socket also gave varying results.
I can only hope that its not the wires, but the plug socket not mating correctly, it definitely does NOT have that solid plug into socket feel that I believe it should have.
Other than the swaping from LH to the RH side of the dash, the cradle has no modifications that I can see, but it may be warped enough to allow the pins at one end to be not correctly seated. But! After perusal of the connector cct/pin layout, I feel that unless we have one earth or power wire crook, then it is an overall plug/socket seating issue. AND.... requires the IC to be removed again, if only I had a new clean plug that I could set up up to test every cct. If only.

[sirfixalot]

Doug they are available on ebay seller is     chrishartung seems to have lots of plugs,connectors,crimps, I was going to buy some off him when I had trouble with injector outputs on computer

[Vettech]

Thanks Sirfixalot,  I'll look into that.
However after another close look, it looks like the metal bracket the cradle secures to is not GM, looks bent / warped, so I removed the two and 1/2 screws - yes a broken off 1/2 screw, this released the cradle from the metal support right at the connector (there is sufficient other support) and the IC now plugs in with a very positive feel, and like magic, it all comes alive & works well. I then went to town on the dash etc to try and bring the fault back in, thankfully everything is ok. Success at last.
Now to find those vanishing screws and put it all back together  - but thats tomorrow.

[Vettech]

Well except for the lower footwell padding and lamp, its all a goer.

This 90 is what is known as a "so called" Chain&Bar conversion, as opposed to the "Mirror conversion" of which I'm well and truely fed up with, as far as handling, responsiveness and ease to work under the hood, these C&B's are as good or better than the Mirror's.

I would suggest to anyone with series 2 C4's (i.e 90 onwards) with Instrument Cluster issues to look to the connector at the rear of the cluster.

Now for those pesky seat pumps - but thats a new thread......