PDA

View Full Version : Wiring & Cruise Control Questions


wthif
11-14-2007, 14:25
• I want to remove my old cruise control system (that sits on inner fender well). I will need to install a new speedometer cable if I do this. How do I get the old cable out of the firewall and the new cable in? Looks like rubber grommet was formed around the old cable when it was install and doesn't appear to be room for the ends to make it through.

------ Wiring Questions ------

• Why did GM wire the starter and alternator the way they did? Seems like GM ran more wires than they needed to.

• Can I just run a battery cable and the (pruple) start wire to the starter?
• Can I just plug in the two wire plug into the alternator and no extra wires or do I need one more to carry the charging load to the batteries?
• If I were to run the wires this way I would also need to get a wire going to the junction block on the firewall from the battery. Which could be done a couple of ways.

What confuses me is GM ran quite a few (8 gauge?) wires all over between the starter, alternator, and the junction block on the firewall, before any power even enters the cab and these wires just run back and forth between these three places. This just doesn't make much sense, one could accomplish all this wiring with much less wires; they might need to be a slightly large gauge, but not much. Am I missing something or was GM crazy?

Thanks for your help. I'm pretty sure I know all the answers to my wiring questions, but I start to question myself when I see the mess GM made in wiring.
62K5
11-14-2007, 17:08
You may already know this, and I apologize if you do and I misunderstood your charging system question, but here is a good article that discusses sensing voltage and why it is downstream to account for voltage drop. http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
john8662
11-15-2007, 09:30
Gotta do the same thing in regard to the cruise control on my '82 as well. Shame too, because it actually worked (unlike my blankedy Blankedy 86).

Anyways, the cable will pull out of the grommet from the engine compartment side. The new cable will go back inside the grommet with the aide of some WD40, by inserting from the engine compartment side.

John
wthif
11-15-2007, 13:59
Anyways, the cable will pull out of the grommet from the engine compartment side. The new cable will go back inside the grommet with the aide of some WD40, by inserting from the engine compartment side.

John

Thanks, John

Hadn't had a chance to look at the speedo side of the cable and got a little worried.

-------- On the wiring side of things -------
I'm going to draw a wiring diagram to illustrate the mess, I'm talking about.

62K5, thanks the article was a big help. I don't have any intentions of going to a one wire alternator, but there just seems to be too many wires.

Also where is the voltage regulator on our trucks?
DmaxMaverick
11-15-2007, 14:51
....Also where is the voltage regulator on our trucks?


It's internal in the alternator. If you have one failing/failed, they are an easy and inexpensive replacement.
wthif
11-15-2007, 20:03
It's internal in the alternator. If you have one failing/failed, they are an easy and inexpensive replacement.

If the voltage regulator on our trucks is internal to the alt. the article above doesn't help much. I will post a wiring diagram of what I figured out later (just need to draw it) and I think I need to get my ohm meter out and figure a couple of things out before I ask more questions.

Thanks for the help.
chkline856.2
11-26-2007, 17:08
Any chances you could take a pic of how your cruise is installed in the engine compartment? I'm getting ready to install cruise on my 85, and it would be a big help, also if you want to part with the old cables / rest of the system, I'd be interested. Thanks!
FEF
11-26-2007, 18:56
I like to use cheap hand soap to push things through grommets, and grommets to firewall holes. In this case, the cheaper, the better. It's the white stuff that looks like lard. It's also good for changing tires. :)

I keep it around for all kinds of stuff that needs lube. After a while, the water evaperates, and there's not much, if any, oil residue.

Can't help with the wireing stuff just yet. I'm still getting a feel for how GM does the wire management.
wthif
11-27-2007, 09:28
Any chances you could take a pic of how your cruise is installed in the engine compartment? I'm getting ready to install cruise on my 85, and it would be a big help, also if you want to part with the old cables / rest of the system, I'd be interested. Thanks!

Sorry it is all ready out of the truck. You can have the system though, just pay shipping (PM me). I have no clue if it works. I haven't pulled the speedo cables yet, if you would like those you are going to have to wait.

--------------

As for the wiring I'm going to leave it alone. Made a lot more sense once I drew myself a wiring diagram and took an Ohm meter to the alt. There are a few things that P.O.'s have done that I will fix. I will also replace and move a couple of fusable links.
wthif
12-02-2007, 16:53
Anyone know the length of the speedometer cable from T-case to speedometer? (I'm being lazy, I could just get a rope and figure it out) Parts house gave me an option of three different lengths (75", 80", and 92") and I told them I would be back later. Thanks.