unknown parts. what for?

[Eisenkreuz]

for my engine swap and cleaning the bay i could use some help identifying these parts. it's a 1981 blazer, 2wd, everything manual, no AC, no cruise control...

there's this thing behind the power brake booster
one green cable goes to the trans (is this for Backup-light?) on the other side is what i believe is a vacuum pump. but what use is that vac for?
http://db.tt/2o6Oauqo

and this cable string on the firewall above the trans (with a huuuge rubber gromet)
http://db.tt/freKYhzE

orange goes to distributor i think. the connector with the 4 pins has no equivalent. it's wires are brown, black, yellow, green. also seperate in that string is blue for either water temp or oil pressure

can someone help. didn't find these in a wiring chart.

 

[dyeager535]

Can't see the pics here, but the 4 wire one sounds like trailer wiring to me. 3 female and one male terminal, or vise versa?

 

[Eisenkreuz]

Can't see the pics here, but the 4 wire one sounds like trailer wiring to me. 3 female and one male terminal, or vise versa?

the look is similar, but it´s IN the engine bay, coming out of the firewall above the trans.
think it´s for the dist or something that was once needed for the ignition. maybe external ignition module. but the truck was oem equipped with HEI, so i don´t think it´s for that

 

[dyeager535]

305? 305 used ESC I believe even in 1981, which used the multi-pin distributor.

 

[dremu]

The backup or reverse light should be switched on the steering column, not the transmission.

The vacuum things on/around the brake booster are likely vacuum switches, though I don't know what they do. Might be smog or computer-controlled carb stuff -- I only know about older trucks

The orange one is fairly heavy gauge, so I'm thinking it's the power to the distributor, but again, the four-pin weatherpack, too new for me.

I can see the pix, btw, but can't copy them or save them local to show the folks who can't.

-- A

 

[dyeager535]

Back then all I can think of that would have been a true weatherpack would have been the ESC distributor. But again, (original) 305 truck was the only one that would have had that.

 

[British Slave]

 

[British Slave]

 

[Fordum]

The backup or reverse light should be switched on the steering column, not the transmission.

The vacuum things on/around the brake booster are likely vacuum switches, though I don't know what they do. Might be smog or computer-controlled carb stuff -- I only know about older trucks

The orange one is fairly heavy gauge, so I'm thinking it's the power to the distributor, but again, the four-pin weatherpack, too new for me.

I can see the pix, btw, but can't copy them or save them local to show the folks who can't.

-- A

I can download them and post them here.
But they are too big to put them both in one post. Here is the first.

 

[Fordum]

Never mind for the second.....

 

[dyeager535]

First is the ESC distributor connector, second is the TCC lockup vacuum switch.

No idea what the large single orange wire is.

 

[Eisenkreuz]

thank you so far!

my truck had an 70something engine in it, overbored and stuff, didn´t work well (i just got my new GM performance 350 that i´m going to swap in!) it could be, that it originally had a 305 though. in that case it makes sense, that the connector is on the firewall next to the distributor.
can anyone tell the color codes? so i can use these cables for the new HEI i´m going to throw in.

concerning the TCC, my truck has a TH350. is that trans even able to lockup? thought this was the case with the TH700s or overdrive trannys... (since the gallon is $8 and cruising speed is around 80mph over here, i´ll have to get my hands on a TH700 asap!)
oh, and how does this thing know when to lockup. is that vac hose just going to the intake or where do i get that vac best?

 

[dyeager535]

Must have been a TH350C originally. Those did have lockup converters.

Fairly certain you can't use any of those wires coming through the firewall, nor would you want to. Drop your glovebox and look for a rectangular aluminum "box" fastened to the underside of the dash. Those wires should go to that. At least as I recall. Your truck sounds like it may be early enough that it was done slightly different than later, but the trucks seemed pretty consistent in placing the ESC or ECM in that spot.

One of those *might* be an ignition switched hot that you need, but I don't think I'd want to have that additional failure possibility there. You might very well however, be able to cut and splice into the wire that FEEDS the ESC the ignition 12V source under the dash. If that's how they were run. But very simple to test if any of the wires stay hot in BOTH start/run.

 

[Eisenkreuz]

ok, i checked the wiring, but there´s no aluminum or other box (computer) in the complete system. the wiring string goes through the firewall, then under the metal dash to the drivers side, then splits up in two. one goes to the fuse box, the other half goes to the headlight switch and or steering column. there´s no box inside the complete wiring underneath the dash. it doesn´t look like it has been cut off the wiring!

could the ESC be built into the distributor?

however, i´ll just pull to the inside, then weld the 3 inch hole shut...

 

[dyeager535]

Hmm. Odd.

AFAIK ESC always had a metal "control box". I don't have a manual from that vintage to verify what I think I know unfortunately.

What year is this truck? It could be that I'm totally screwed up and it's not ESC, but from what I know, ESC used that four wire weatherpack connector.

According to my parts manual, 1986 was the last year for a US TH350C in these trucks. Was this truck originally from the US, or is it an export rig? GM did some weird stuff on export vehicles, depending on where they were going.

 

[Eisenkreuz]

hmm, could be a plausible cause. it has a kmh-speedo, so i think it´s either a canadian or even other... i live in germany, and i don´t know the complete history of the truck.

here´s another pic of the firewall where it went through (hole to the left)

pic

 

[dyeager535]

On my '87 that is exactly where the ECM wiring comes through.

There is no white-ish plastic tray behind the glovebox either? It's basically on the underside of the cowl, you have to look up to see it if it's there.

If it's obvious the wiring under the dash hasn't been hacked together by someone, it very well could be some sort of export thing.

Whats the engine VIN for the truck?

 

[Eisenkreuz]

dyeager... the engine code is gone, since the car came to me with a 76 or something overbored 350.

i had a closer look at the wiring now and found something:

the wiring goes to the left side, matches some other wiring and then splits up into two parts. one goes directly to the fuse box. the other goes to the WIPER SWITCH !!! right before it reaches the wiper switch, there´s the missing box spliced in the wiring, just hanging, not bolted to somewhere. it´s a aluminum ribbed box (like a little car amp), with a plastic case around it. there´s "luncton products" printed on it. i think this is it. but WTH is that thing doing on the back of the wiper switch. that´s odd.

so, when it rains, and i´ll go "intermediate wiping" it says to the engine "hey, let´s just fire the spark some more, huh!?" i dunno...

but still i don´t know the right meanings of the cables... should i just unhook that box, cause i´m using 2 wire HEI anyway?

 

[dyeager535]

Definitely weird, I've never heard of anything that you are describing. The windshield wiper delay module is an aluminum finned piece, with two connectors, one on each end, but I've never seen a plastic box around one.

You are saying the VIN from the dash is gone, the one you can see if you look through the windshield on the drivers side? One of the numbers in the VIN tells you which engine the truck came with. 8th character of the VIN indicates original motor...305's here were "F" or "H".

As you say wiper switch, that puts your truck around an '83 at the latest, I *think* the wiper switch went to the column in '84.

 

[Eisenkreuz]

oh yeah, that might be the delay module.
so there´s no ESC module at all. i could take a video of the wiring...
but nevermind, i will just pull the wiring to the inside and weld that huge hole shut.

but the other question is: when i don´t have the ESC wiring communicating with the rest of the system, can the transmission get the signal "when to lock up the converter" just from the vacuum on intake and/or carb? or does it need the rpm's from the HEI???