New harness in the Sy and now it won't start

[bg_bls]

Re: New harness in the Sy and now it won't start

Then you have a Syclone IP harness. BUT, because of the other differences (red 2-pin for dome/key buzz, inside rear-view mirror black 4-pin) this indicates to me that it is a later (service replacement) harness. The pick-up harness got these changes for 1992.



This is important. The white 10-pin "C212" is near the ECM. Look at position 'D'. (there are little letters on the side of the plastic). There should be a pnk/blk wire in both halves of this connector. IF it is missing on the IP side of C212, THIS IS YOUR PROBLEM. This circuit 'energizes' the ECM w/ key on. Later harnesses don't have this connection in C212.

Look VERY CAREFULLY at your C212. There should be matching colors in ALL 10 positions. Report any differences. And we'll discuss the best way to 'patch' it.

Dave

Well that could be the problem because I only have the pink/blk wire on the engine harness side. Most of those wires do not match up in that connector.

My friend just sent all the pics he just took, so here are the latest connectors that do not match up: http://www.b-gcomputers.com/.tmp/sy stuff/Syclone/

I didn't see your post before I left or I would have written down the exact wire colors/positions for you. Let me know if you can't make out the colors and I will go back and make a list. If there is a way I can repay you for your time/effort just let me know :tup:

 

[bg_bls]

Re: New harness in the Sy and now it won't start

It looks like it is not as bad as I thought.

top row old harness----top row new harness
orange/black--->orange black
green/black--->light green
white--->white
brown/white--->brown/white
orange/black--->dark green

bottom row old harness----bottom row new harness
purple/white--->white
purple/white--->pink/black
white/black--->white/black
brown--->brown
orange--->orange


Thanks!! :tup:

 

[bg_bls]

Re: New harness in the Sy and now it won't start

I am going back there tomorrow morning to look into it more. I know they plug in fine at the cluster, but I didn't check all the wire colors.

I think I remember there being a "crank" fuse.

I will get you some definite answers tomorrow morning.


Brian

P.S. There is a box under the steering column that says "AC" on the side of it and it has a wire running all the way to the smaller plug on the AGS box outside the loom. Any ideas what that could be?? That is the way it was wired when I originally took off the dash and it does not look like a factory job. I am thinking there used to be an alarm on the truck before I bought it because some of the ignition wires were spliced into under the column as well.

 

[bg_bls]

Re: New harness in the Sy and now it won't start

Good news!! I have ECU power. :tup: I haven't finished wiring the rest of them yet. I wanted to just get it running so I can bring it home to make it easier to work on. It hasn't started yet, but I think that is due to it sitting for so long. I am gonna get some fresh gas in it and replace the usual ignition culprits and see what happens.

I don't have my notes in front of me, but there are a few wires missing at the cluster like you said. I will give you some more details probably tomorrow afternoon.

I just wanted to let you know we are making progress. :woot:

Thanks again,
Brian

 

[bg_bls]

Re: New harness in the Sy and now it won't start

Any up-date on this project???????

Did you get it running???????

Curious,
Dave

Hey man,
Sorry for the late reply...just been real busy lately. Once I got power to the ECU the truck fired up, but was missing a little. Found a loose sparkplug wire and that fixed that. Then the truck started running REALLY rich at idle. Found the stock FPR took a crap on me. I replaced that with an AFPR, but it is still running really rich, enough to foul out the plugs within minutes. Eventually the truck dies and the plugs are soaked. The FP is within spec, so what else would cause the ECU to dump so much fuel??

I did NOT connect those last wires at the cluster just because I did not want to add to the problems. Unless you think that could be my problem??

The truck has been sitting for quite a while, but I have gone through and replaced all the normal maintenance items. I will try to get a log from DM and see if anything stands out to me.

Thanks Dave for the follow-up :tup: I should have some free time this coming week to work on it some more. I just want to drive the damn thing again....it has been sitting for way too long :myclone:

 

[bg_bls]

Re: New harness in the Sy and now it won't start

Are you sure it's ECM-commanded, and not injectors leaking, fuel pressure, or possibly MAP-related? Check it with DataMaster, yes. But, read on, first:



No,the wires at the cluster wouldn't be an issue BUT:

At C212, 'K'. IP side is an orn/blk wire. cut this wire. I don't know where it goes, but we don't need it. The grn on engine side is the boost guage. It has to do with MAP signal. Perhaps this wire is affecting the MAP signal, causing over-fueling.



You're welcome. Glad I could help. When you're ready, let me know, and we'll finish up the details at the fuse box, cluster, etc. CUT THAT ORANGE/BLK WIRE, before you do anything else. That could well be the overfuel problem.

Dave

Well I swapped map sensor and same problem. All the plugs look almost the same so I don't think it is injector related. My fuel pressure has been rock solid, so I don't think it is that either.

I will cut that wire tomorrow and see what happens. That would be awesome if it is something so simple. Definitely would be a first with this truck :lol: I'll try and get a DM log posted if that does not solve the issue.

Thanks,
Brian

 

[JSM]

Re: New harness in the Sy and now it won't start

I had a bad ecm do that before.

 

[bg_bls]

Re: New harness in the Sy and now it won't start

I had a bad ecm do that before.

I have swapped ECM's and memcals too.