Need some basic info on LS wiring harness

[workingdog]

Okay, I've been beating my head against this for a while.

I'm trying to get cruise control working in my '84 LC with 5.3/4L60 before driving CA -> NM -> MT and back to CA at the end of July.

I've looked and looked at the LT1Swap info, but cannot get it to jibe with the Howell harness I have installed and I'm hoping someone can 'splain what I got to me.

LT1swap talks about connectors going to the fuse block - but I've got no fuse block, so I don't have the C2 connector they refer to. I have the PCM and it's connectors, I've got a what I assume is a throttle control unit on the firewall with a bunch of wires going to the throttle. But what I don't have is a set of wires going into the cab that match the color codes LT1Swap describes.

In a Howell harness, when there is no fuse block, where do the cruise control wires come from/originate - the PCM or the throttle control unit - or both? When I call Howell, all they will say is that my harness has the same color codes as the original GM harness - but that's not much help if I can't find them.

Peter

 

[spotcruiser]

What year 5.3?

 

[workingdog]

2005

I found a wiring diagram here Drive by wire that showed the pin outs for the throttle control module and that the grey wire should be in the 16 wire connector going to the PCM and throttle body. My throttle control module is almost impossible to get to, I'm going to have get at it, and that should show me where that grey wire described in LT1 swap goes - and tell me where the rest go as well.

 

[spotcruiser]

It looks like all of the information is there on LT1, but you'll have to make the connections point-to-point since some connectors and wires don't exist on your truck. No big deal, really. Find what you need for sensor inputs, switch inputs, TAC connections, and PCM connections and wire them. There are really just a handful of connections needed, but the engine schematics make it look worse than it is, so print out the schematics from LT1 and highlight just the connections you need for cruise. I haven't worked with a later-model PCM, but I was able to find pins for my '96 5.7l at Mouser Electronics, so I was able to make whatever connections I wanted. You can probably do the same.

 

[workingdog]

thanks,

I wish I had a better idea of how my Howell harness was actually run, I don't know where the cruise runs from the TAC, but I'm going to trace back the Throttle Module next week and that should tell me where the wires I need are.

 

[NCFJ]

Have you contacted Howell?

 

[workingdog]

All they say is the color code matches the original GM harness, other than that, they were not very willing to help me out in how the thing is laid out. They pointed me at the GM wiring diagrams - which ain't the same as what I've got.

 

[reddingcruiser]

2x Howell EFI

 

[workingdog]

I have a Howell, I've talked to Howell, they were not helpful, the manual is useless.

 

[workingdog]

One of my problems is that the bundle of wires coming off the bottom of the Throttle Control Module is almost impossible to get at. I'm looking for a diagram of where the cruise wires go from the TCM? Do they just go straight into the cab? Or do they go to the PCM? Because this is a Howel harness in a LandCruiser, this set up has no fuse panel, which is the factory diagrams show these wires going.

 

[workingdog]

So, I solved this. When you call Howell they'll tell you that you get the color codes from the factory manual. Okay, did that, not making any sense. Get to the C2 connector on the Throttle Control Actuator and the colors are not the same. Call Howell -
Howell - Oh ya, we changed those.
Me - Well fxxx me. Can I get the color codes for the harness I have?
Howell - Well, they are factory colors.
Me - But you just told me they were changed.
Howell - Ya, we had to change those.
Me - can I get what you're looking at?

that went on for several minutes. Turns out they changed the colors of 2 of the 4 wires in the cruise control bundle (and from what I could see, quite a few others in the TAC module).

So I had what I needed in the cab the entire time, there was just no way to know that. Not very happy with Howell this morning.

 

[workingdog]

Did all that, cruise control still not engaging. Double check I'm getting +12 to the Cruise On wire and +12 to the Set wire, not I'm confused.

 

[Aussie FJ40]

I thought that cruise control worked off a chip in the rear wheel bearing, I may be wrong

 

[workingdog]

Huh?