i replaced my old shitty harness with a nicer used one. looked it over before i installed and it looked good.

got everything hooked up, connected, grounded, and the whole car is dead. battery is charged, posts are clean, cables are good.

used a test light and i'm getting power to my alt and power to my starter. what could be wrong?

 

Any power at the fuse box?
If not you are missing the main power supply there from the batt

 

Not sure, but I assume there wouldn't be

 

Bad assumption given most of the car power is fed from the fuse box.........

 

fusible links?

 

well my assumption was correct lol

fuseable links you mean by the starter wires?

 

Did you remember to plug the harness in to the starter switch at the bottom of the column? It sounds like a problem there or the fuse block that feeds that circuit power.

 

yes there is no power to the fuse block

i never unplugged anything underneath the steering column when i took the old harness out.

 

Check:
- that the wires are hooked up to the starter positive post and have power
- that you have power on connector C100 that feeds your passenger compartment

It could be bad fusible links or a bad connection on C100. Possibly a miswired C100.

Hope this helps.
Lou

 

there is power to the starter cables. i was talking to someone who was saying there should only be 2 posts on the starter however i have 3. and my previous harness used all 3 cables.

where do i check for power at the c100?

 

Big thick red wires on A4 and G5 bring the power to ignition switch and the fuse box under the dash:

http://www.austinthirdgen.org/mkport..._1989_C100.gif

Hope this helps
Lou

 

So do I just take a test light to a4 and g5 on the engine harness side?

 

Yup.
If you have no power there, I'd blame the fusible links on the red wires on the starter.

 

Well I have no power to those.

And I went underneath and probed my starter terminals and wires with a DMM and the fuseable link wires have no power and the big thick one has under 10v. Battery is currently at 12v

 

There is something wrong with the big thick wire that brings power to the starter in the first place. It should be at 12V, just like the battery. Check the battery terminals and cable. There could be a bad connection somewhere.

 

Well i did some testing tonight and this is what i found

The battery cable that goes to the starter had quite a bit of resistance in it. Did some more testing and cleaned off the terminals and the cables, took care of the resistance issue.

now get 12v going to the starter, but nothing coming out from it.

removed the fuseable link wires from the post on the starter and placed them over the known source for 12v and got voltage at the C100

so would this be a bad solenoid more than likely?

 

This statement begs the question: did you remember to put all the wires on the same post on the starter? The supply wire from the battery and the fusible link wires must be attached to the same post.

Hope this helps.
Lou

 

For some reason i don't remember them being together, but it makes sense.

I have 2 other posts there though.. what goes to them?

 

A standard starting solenoid uses 3 posts, 2 big post + one small post.
One big post already has a wire going into the starter from manufacturer.
The other big post is for the big cable from the battery, to supply voltage.
The little post is for the starting wire (from the ignition switch). On our cars, it is purple.

Chevy decided to use the big post with the thick cable from the battery as power distribution post. So they also attach the fusible wires to it and that powers the fusebox in your car. It is an idiotic system, many will agree. But hey, you wanted a Chevy, you got a dumb Chevy. "Like a rock!"

Hope this helps. Your car should have power after you place the wires on the right terminal.
Lou

 

Lol yea it all makes sense now. Thank you for your very useful help. I'll try that later once I get home from work and see what happens

 

Ok now I have power! Great!

Next thing though. Not sure if power is getting distributed everywhere. I turn the key to run and all I have is the click. The starter will crank but the fuel pump won't prime. Probed the ECM/fuel pump fuse near the washer tank and it's dead there

Probed the fuses under the dash and there's no power to the crank fuse.

How can I check to see if my ECM is getting power?

Keep in mind half the interior is torn apart as well as the top half of the engine. But the majority of the important sensors are plugged in and everything regarding ECM electrical is connected inside. Don't have the gauges plugged in or a portion of the dash

 

The ECM/FP fuse is fed from the same fusible links that you have on the starter. Are you sure all of them are there? (http://www.austinthirdgen.org/mkport...F_and_vin8.jpg)
The crank fuse has power only while cranking.
Portion of the dash is not plugged in? I hope your C207 is because it feeds the power to the injectors etc.

Other than that, I do not have any good specific advice. You will need to double check all your wires.
It's a gorgeous car, I want to see it run again!

Lou

 

I'm wondering what you can tell me about this guy:

I have power, starter turns over now, and i have spark. I do not have fuel though. And my problem seems to be that this relay type thing is not getting power, in turn not energizing the other relays including fuel pump.

Where does this relay thing get it's power from?
What sensor signals does it need to see in order for it to energize? I do not have the top part of my intake hooked up. Does it need to see MAF or TPS or something?

 

The wire colors on the relay do not correspond to any relay I know or any diagrams I have so I cannot tell you which relay it is, sorry.
What is the color of the thick wire on the left? Yellow? White? What about the thin wire next to it? White?

So you have power on the orange supply wire? If you unplug the relay and jump the first and last position, do you have fuel?

Lou

 

it's the relay next to the fuel pump relay by the brake booster.


the connector differs from the original wire colors. somebody had added replaced it at one point

looks like the original colors are orange, red, tan with white stripe, and blue or green.

 

Thank you for the clarification of the colors, that's what I needed.
What you are looking at is your fuel pump relay. The tan/white is the wire that supplies power to the fuel pump (and a few of the MAF relays) and the control wires (if I see correctly) are green/white and black/white.
Good photos, thanks.

Did you try jumping the first and last posts? (you can use a standard paperclip)

When you turn the key to the On position, this relay should click and prime the fuel system for 2 seconds and then shut off. So if you turn your key on and then go measure under the hood, the relay is likely already off. You need to account for that when you are testing it. It would help to have someone else turn the key when you are holding the relay and feeling for the click.

If the relay does not click, use a voltmeter or test light to check for power on the little green/white (original) wire when the key is turned on. Check the black/white (original) wire for good ground. If both potentials are present and the relay does not simply click, it is likely bad.

However, if your wiring harness is installed properly, your oil pressure switch should supply voltage to the fuel pump (tan/white wire) once you build up oil pressure. That means you need to crank the engine long enough to build up enough oil pressure to close the switch and get the fuel pump running.

But like I mentioned earlier, you can just use a paperclip to jumper the relay socket to get fuel.

Hope this helps.
Lou

 

So do you suppose that if I apply direct voltage to the orange wire going to that 20A fuse for the ECM/fuel pump that it would work for now?

 

If you don't have any power on the orange wire, I'd trace it and see why it is not getting any voltage in the first place. You could try putting power on it but be careful. It could be mistakenly grounded or something and that would not be good.
But putting voltage on that orange wire and using the right fuse in the fuse holder should be enough to give you power for the fuel pump and ECM.

Let us know what you find.
Lou

 

Ok so I put direct power from the battery to the orange wire by the fuse. I hear the relay click but fuel pump doesn't prime. Is that because I activated the fuel pump a few previous times and it sees there is sufficient pressure in the rail?

 

The fuel circuit does not use any pressure sensor to detect whether it needs to prime or not. The ECM simply turns the fuel pump on for 2 seconds after the key is turned on and that's usually enough priming.

If the relay clicks, that's a good sign. One problem solved.
Now do you have power on the yellow wire at that relay (originally orange in the harness). If not, that would explain why the pump does not come on.
If you do have power on the yellow, check the power on the big green wire (originally tan/white in the harness). If you don't get power there when the relay clicks, you might have a bad relay.

Let us know what you find.
Lou

 

Well there is power to the yellow wire. However, nothing at the green when the relay clicks. But if I apply direct power to the green wire the pump primes. So that may indicate a bad fuel pump relay then?

 

That sure sounds like a malfunctioning relay.
If you have another one, you can swap them and see if that fixes the problem.

 

Unfortunately I don't. But I can't imagine they'd be too expensive. Is there a way I can test the relay itself? And would that explain why there isn't any power going to the orange fused wires?

Also, I really appreciate how quick you are to respond and your well thought out answers. Thank you

 

Having the relay plugged in and hearing/feeling it click is a good test.
Besides a bad relay, one other possibility is a bad contact of the relay in the socket. But a new relay should clear that up real quick. IIRC, they go for around $10. Does your old harness have a spare relay?

Glad I could be of help.
Lou

 

It does not have a spare. The old relay is still being used. And the previous harness had the orange fused wire connected directly to the battery as well which might be a clue about the relay perhaps.

 

So with a bad relay that wouldn't allow power to the orange fused wire? Isn't that wire supposed to be hot at all times?

 

The relay does not supply power to the orange wire. The orange wire is supposed to supply power to the relays.
Trace the orange wire through the harness, if you can. It must be connected to the battery (according to this diagram). So I would double-check the thin wire connected to the positive battery terminal. Tracing that wire by the battery should be easy, it shouldn't be hiding in any looms.

The 20-amp in-line fuse should be right by the battery, usually attached to the fenderwell. It looks like a connector that is not connected to anything and it has one red and one orange wire.

Hope this helps.
Lou

 

If the old relay worked before, I would say check the new socket for bad contacts. They are standard knife receptacles and if they are loose, they won't make good contact. Like I mentioned before, it's either a bad relay or bad contact.

Yes, that's how the harness should be, the 20 amp in-line fuse should connect directly to the battery, via a red wire and possibly a connector. (harness might vary by year and model)

 

ok so here are pics of what i have going on:

this is the ECM/fuel pump inline fuse and wire. Not sure if that connector came from the factory or if it was added. looks like it was added in.

and hopefully a better look at the fuel pump relay and wires:


with the key on and direct power applied to the red or orange wire with the fuse, the relay clicks, but no fuel pump

On the relay side: With direct power applied to the yellow wire(orange wire), relay clicks, but no fuel pump

With direct power to the green wire(tan wire), fuel pump primes.

In that diagram and also what you were saying, the red wire with the fuse side should be directly connected to the battery with a connector or something? Mine currently is NOT directly hooked up to the battery, and if it were, the relay would only click but still no fuel pump prime.

Now, you were also saying the contacts on the relay connector could be bad. is there a way i could repair those at all just to be sure? Or just by looking, could i tell if the receptacles are shot?

Perhaps i should take the old connector from the old harness and wire it on the new one to see what happens. But that connector looks worse compared to the one i'm currently using.

Hope this is clear. I can tell I'm so close to the issue, and it's right under my nose.

And just for good measure, i took a pic of the relay connector:

The far left receptacle is the fuel pump wire, the far rights is the power supply.

 

Hello back,

the pictures help, thanks a lot.
The fuse holder is exactly what came from the factory. We just need to find where the red wire is going to. It must go to the battery. The loom is not that complicated this close to the battery, it should be easy to follow.

The relay socket looks very good, no reason to suspect it being the culprit. At this point, I really think that the relay is the problem if you get no power on the big green wire when the relay clicks.

Hope this helps.
Lou

 

So I got a new relay. Nothing changed. Now what?

 

Aw, donkey butter!

That would mean that the problem IS in the socket somewhere. It looked good, visually. But if you could try to spring up the contacts, it might help make contact on the blades.

I am making a conclusion here that it is a bad solder joint on the thick green wire because when you used the paperclip to jumper the two outermost contacts, your fuel pump came alive. So we can assume that the socket has good contact to the harness. The only unknown would really be just the springy contacts inside the socket. I definitely recommend checking those out.
You can also try to bend the relay contacts a tad to make them engage the socket blades under different angle, it might help with mechanical preload and better contact surface.

I saw your voltmeter there so I know you know what you're doing (which is always good, especially troubleshooting over the Internet). So have a go at it and let me know what you find. I really want to see your car run again.

Lou

 

Well Lou, that advice did it bent the contacts on the relay slightly and bang! She worked! Thank you so much. You have no idea how appreciative I am this car has been fighting me since August last year!

 

So my night is going quite well! Car attempts to start which is better than it has been in 9 months! All i'm getting is just some popping, and fuel smell.

A few months ago, i removed the engine and fixed a few of its major oil leaks. I never removed the heads or cam shaft or anything internal. Isn't the car supposed to time itself electronically? Or is there something i need to do first? It sounds like it is off time to me anyway, unless the fuel is just too stale

 

I am very glad that we got that problem out of the way. Now you need to get her running.

Thank you for posting follow-up, hopefully it will help somebody in the future.

Yeah, I am in the same boat, I own a Chevy too.

 

Our cars time themselves off the distributor but that one needs to be installed and rotated properly for the timing to be right. IOW, you have to ensure that the distributor is adjusted well.

Did you remove the distributor during your engine work? If so, you will need to re-time it. (if you removed your intake, you must have removed the distributor, Chevy's are built that way)

Your fuel should be good enough to start the engine, even if it's a few months old.
The standard test is: spray something flammable into the intake (carb cleaner or so) and if the engine fires up, you have either bad or insufficient fuel. If nothing changes, it's spark or its timing.

Hope this helps
Lou

 

Yes I removed the distrib. I've never timed a vehicle before so I'm kind of new at that lol. So I should remove the cap and turn the distrib? How do I know how far to turn it?

 

In that case you will have to time it.
You can search for spark timing here, I am sure you will find a lot of information. Or you can consult your repair manual. You will need to borrow a timing gun, if you don't have one.

But if you feel adventurous and can set timing by ear (I've done it many times), you can try just loosening the distributor hold-down bolt and turning the whole distributor (with the cap) while trying to start the engine. If it fires up, fine tune it by ear.
You are limited to only certain degree of freedom when trying to turn the distributor, due to the spark plug cables on top and the wiring coming from the back. If you cannot turn it more but your engine still doesn't start, you can remove the hold down bolt and distributor cap and lift the distributor enough to disengage the cam gear on the rotor and turn the rotor about 90 degrees, stab the distributor again, replace the cap and repeat the procedure, fishing for the right spot.

Good luck with that, I cannot help you more over the Internet. (wouldn't it be cool if we had robotic arms that we could control remotely? )

Lou

 

well it's running again needs to be timed, but she'll start and attempt to run a bit. so that's something i'd say!

thank you very very much. you were extremely helpful!

 

That's good to hear and I am very glad I could help!

Now would you want to put an STS unit on the car to sequence the turn signals? You KNOW you want to. And your car is the perfect candidate.