Duramax Diesel Conversions

[Margo_325]

To Jim: I´m using a Duramax steering column as well. Theres minor problems fitting it, because the lower bracket does not fit and needs to be welded to another place. Same with the shifting cable bracket on the steering column, because Im using my original Suburban shifting cable (it is tight)

To THEFERMANATOR: Could you explain it to me (a simple schema or something), because I have zero knowledges about relays. I know, that I have one wire, what turns on the light in the A/C button, if I give there "+" from battery.

[THEFERMANATOR]

The A/C control head in the 95-99 SUB's output's a 12V+ signal to the A/C system to request the compressor to come on. The 01 DMAX uses a ground signal from the controller to the ECM to trigger the A/C. So you would need to use a relay that is turned on by the 95 control head that would ground the A/C request signal to the ECM. And the A/C light in the control head is turned on by a controller inside of the A/C control head itself. Also the power for the blower motor in the HVAC comes through the origanal underhood harness that ran behind the engine and came down underneath the old coolant bottle. This is the same harness that origanally had all of the ECM wiring in it.

[Margo_325]

Ok, I think I try to do so. Another sad surprise came up. I connected all wires, that is needed to run the engine, so I can start wiring power windows, electric seats etc. I turned the ignition on and only this yellow "Check engine" and glow plug lights came to life. As I don't have any oil in the engine, I didn't try to start it yet, just tried, if starter works and it did. Of course, I don't have a key, the lock cylinder is taken out and I have a big screwdriver as a key, but still, I suppose, Passlock will not disable any lights like battery or oil in dashboard? No gauges were working either. Its weird, because I haven't done any wiring myself, besides these red wires on the picture (they fit anywhere, so I did just put them somewhere)

And also thereare 2 plugs left over under hood:
(comes out from that red box)

and two ones under dash: (yellow one seems to be like airbag plug, but that already connected on the steering column)

Any ideas, where I should start tomorrow?

[More Power]

No gauges were working either.

Several of the gauges are operated by the vehicle ECM via digital data - not directly by engine sensors. So, the ECM has to be installed for all of the gauges to work as they should.

I would expect some modification of the steering column mounts would need to be done to get the newer style column installed. That is all pretty basic, and having the new correct column would make the overall installation a lot simpler. Personally, I'd get the correct Allison shift cable, and not try to reuse the original Suburban shift cable.

If someone else started the electrical/electronic installation, and didn't document everything, you're in for some late nights tracing wires and figuring out what was done. In my conversion, I documented everything, and kept detailed records, both to help me in the future if I need to troubleshoot a problem and to help any future owner should I sell this truck.

One aspect of the conversion I kept firmly in mind during the process was to keep the conversion as "factory" as possible. Any deviations from this are thoroughly documented (like the HVAC, wipers, etc). This would allow a GM dealer technician to troubleshoot this D/A conversion just like he would a stock 2001/2002 D/A truck. Nearly all circuits, fuse blocks, individual fuses, harnesses and all electrical layout are almost exactly as they are in the 2001/2002 trucks. The conversion guide was written from that perspective. One reason for doing this was because no one else had completed a GM truck conversion at that point in time (in 2003/2004). If I needed help from the local GM dealer, I wanted them to be able to use their routine troubleshooting resources to help. I knew that custom wiring, custom ECM/TCM, mismatched wiring and mismatched circuits would make it nearly impossible for another person to help. And lastly, I wanted this conversion to look as neat and professional as possible.

Jim

[Margo_325]

Ok, after hours searching, I managed to get my instrument clusters working. It was some grounds, that werent connected. Of course, now it works when ever wants, so some more problems to search for. Now I´m stuck again, because of the fuel pump. I have the suburbans fuel pump, but no duramax one. Where should it be located? I checked the fuel tank, but there was only the level indicator and in the tank there were going only 2 wires (purple and black, probably for level indicator). I have alldata opened, and it shows, that both cars have same colour fuel pump wires (grey and black), but I cant find any available connector in my duramax harness. I used all duramax harness (C3 and C4) under my car. Of course, one opportunity is to make new harness, going from fuel pump relay to the fuel pump, but why to invent something, that should already be there? The alldata shows this diagram:
http://stuff.e30club.org/images/subu...el_control.gif

Also a quick question, how the tail lights should work? There is going 4 wires in, but theres 3 bulbs, each with two strands (or how it is called in english). I sorted out the right wires from Duramax harness, but now idea, how to connect them with suburban lights.

[ToddMeister]

Margo,

The duramax does not use a fuel pump in the tank, the CP3 pulls fuel itself from the tank thru the fuel filter and up to the pump.

Some folks add lift pumps on the frame rail to help the CP3 get more fuel. They will run the pump thru an oil pressure switch so the fuel pump turns off when the engine is not running.

[Margo_325]

Okay, now I just connected the fuel lines, but as suburban has smaller pipe coming out from fuel tank, does it affect the engine work? Today I filled engine with oil and tried to start it with my "screwdriver key" and it actually started for a second. Of course, Passlock then interrupted. What I noticed, that if I turn ignition on, then on the info panel in the dashboard, it says: "Driver 1 - Odometer: 116000 - Low Fuel, Service 4WD, and then it stays at odometer (you can change by hourmeter, business and so on from the button there). But in the book, I saw, that Jim had all gears marked up there (P, R, N, D, 3, 2, 1), if the ignition was on. Well, Jim had little bit different instrument panel as well, but I still think, that it should show it. I got the tail lights working after some hours (in Europe you have to have amber indicator lights, so thats way I was confused).

PS! My headlights are acting weird. When I turn the ignition on, then theres low beam, if I change to high beam, the low beam goes off, actually they both should be on...