knightinblackar

Hey guys,

Been doing a full restoration on this 2.8 of mine and I've had the entire loom out of it. I've replaced everything as I think it should go and everything was labelled. The only things i haven't reconnected are things like smog pump, egr valve, vacuum control switch etc which have been binned.

The problem I'm having is when I turn the key there are no gauges. Nothing. The only thing I get lit up is the seatbelt light. There's 12v at the yellow starter cable from the key switch in the crank position as I've checked it. Theres 12v at the solenoid too. The weird thing is that when I press the trunk release button all the gauges move clockwise with the ignition on, and anti clockwise with the ignition off and the BRAKE light comes on real dim. I'm thinking bad earth maybe on the dash but the only one I can find is the little one to the left of the steering column bolted to the dash frame.

I have had the column apart to repair the wonky column problem and I'm wondering if there's anything I could've broken but it all came apart and went back together very well and nothing was fitted wrongly or broken? Is there a power wire for the gauges i can test?

I've been at this ALL weekend and I'm now getting well and truly sick of it. Everything else on the car works, so far. lights, heater blower, fuel pump, turns and hazards, interior lighting, just not the dash gauges and I have no starter.

Before you say it the starter has been tested and is working fine on the bench!!

Also I seem to have two unidentified connectors under the dash, can anyone ID them for me?

This one has two wires, pink and purple. Coming from the loom for the steering column.



This one is purple with a white stripe and is coming from the very left corner of the drivers footwell.

Ok so I know what this is now. It's the rear defrost. One down!



It's got me foxed as everything I need is plugged in, the cruise connections, clutch bypass, brake light switch. Really really need some help on this one!!

Six_Shooter

iTrader: (2)

Engine grounded? Ground straps between the battery and chassis and between engine and chassis?

knightinblackar

Ground between back of block and firewall, all the grounds to back of block. Grounds on either side of radiator, grounds on either side of trunk release servo, ground to beneath centre console, ground to dash frame to left of steering column. Ground to front left engine block from battery. Can't think of anymore!!

RBob

iTrader: (1)

I agree that this sounds like a bad ground (earth). The ground to the left of the column is the one for the dash. It may be a bad connection to the cluster flex circuit, or a broken trace on the flex board.

It is for an automatic trans TCC lockup, which your car doesn't have. So the connector isn't used.

RBob.

knightinblackar

The strange thing is that the column is throwing out 12v down the yellow crank wire. I'm wondering whether having the wiring looms out has disturbed some fragile fusible links and they're no longer sending power to the starter? This all worked before I took it apart and I can't find any grounds that are missing or not connected.

Short of tearing the dash out again and all the looms I don't know what to do.

Question. From the crank fuse where does the power go? According to service manual it's straight to the starter via a purple wire, but there's no purple wire on the starter. Never has been.

Question 2. Will the car start and run whether the gauges are working or not? If I treat this as two separate issues can the starter problem be resolved and tested and work on the gauges later?

Question 3. If the little black earth to the left of the steering column mounted to the dash frame is all that grounds the dash am I to assume that the dash being bolted to the frame of the car completes the circuit? Also I've added a separate ground from that one on the frame direct the battery and it made no difference whatsoever!

This is a nightmare!

knightinblackar

Another thought is that if there's only one ground wire on the dash frame all the grounds must be spliced together somewhere in the loom. They're obviously working as all the dash illumination is functioning. Confuzzled.

RBob

iTrader: (1)

Check the clutch switch, see the attached image for the wiring. The yellow wire goes to the clutch switch then changes to purple for it's trip to the starter.

Yes, no need for the gauges to run the engine or starter.

RBob.

Street Lethal

iTrader: (16)

That is what it sounds like, the fusible link down by the starter...

knightinblackar

Thanks RBob, I've got the 85 shop manual so I've already got this diagram. The clutch switch was dead so for the purposes of testing I've connected the wires together.

Great news on the gauges. I'm gonna get a brand new battery too and see if that makes any difference. We'll see.

I'll also be taking the starter wiring back off and rewiring it all to at rid of those stupid links. I'll add an inline fuse of suitable rating.

I feel a little more confident now thanks to all of you.

knightinblackar

Ok guys to fill you in it wasn't the fuseable links. Ive spent the entire day on this.

Bought a new battery to make sure I had the best chance and started from scratch. I put an inline switch between the battery pillar and 'S' pillar on the starter solenoid and it turned over no problem.

After a whole load of messing around tracing wiring all over the place it turned out to be the wire I had used to extend the clutch bypass to a switch. When I tested it the wiring was reporting a 25A draw. When I removed my section of wiring and simply connected the wires together it reported a 5A draw and turned over fine. So it looks like it simply couldn't get the power down the wire, which is odd because I used 16A wire, but I assume because I altered the length the current and resistance changed.

Anyway I still don't have gauges so tomorrow's job if to take the loom apart behind the dash and make sure all the grounds are connected and working well, then I'm going to ground the dash separately as well as the stock grounds. All I can do is try right?!

knightinblackar

Well another full day on it no further on. Still no gauges.

Functional :

Illumination
Left turn
Right turn
High beam
Seat belt warning light

Non functional

Tachometer
Fuel
Oil pressure
Coolant temp
SES light
BRAKE light

I've had the loom apart behind the dash and the grounds are all absolutely fine. I've had the gauges out of the car and tested every single track on the circuit and they're all fine. When I apply power to each telltale they all light. When I apply power to the gauges they move. But when it's in the car, absolutely nothing.

I'm at the end of my tether with this and really need some help. I get one day a week usually on this car and so far this problem has cost me three weeks!! Any ideas and I'd love to know.

Thanks in advance.

ktthecarguy

Hi there,
I don't know if this has been covered yet, but did you check the two fuses by the battery, on the inside of the fender (wing)? One controls the ECM, the other controls the fuel pump. My "check engine" light would not come on at all, until I replaced that fuse.


Just a shot in the dark. Even if they look good, try replacing them with known good ones. Hope for the best!

knightinblackar

Well we got the car started today. Had the wires 180 degrees out. Don't know how, but we managed it.

Still got no gauges and the trouble shooting procedure in the service manual is so complex I'm getting lost. There's no power to the SES light when the ignition is on. I've checked it with a test light. None of the gauges are working, they're not doing anything. But I have all the dash illumination and the turn, main beam telltales working fine. I have seat belt light and that's it.

No response at all from any gauge. They don't even zero when the ignition is switched on.

Help!!

Ps thanks for the hint on the fuses. I'll change them out now.

knightinblackar

Another day through and no dash gauges. Absolutely nothing.

I checked the two fuses on the passenger side near the front of the car and they made no difference when I changed them for two new ones. There's was nothing wrong with the old ones. I changed the gauges fuse too, and no difference.

I'm seriously at the end of my tether with this now and I cannot understand what's going on with it.

knightinblackar

Ok I fixed it. Behind the gauges in the main dash loom are several pink/black wires which are all spliced together. Two of them had snapped, just happened to be feeding the buffer positive for the gauges. What a nightmare this has been. Hope this helps someone else.