need help with parts ID - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*1FaastC10* · 09-09-2003, 09:58 PM

i need to know what these parts do, and what they are. hopefully you guys can help...

*1FaastC10* · 09-09-2003, 10:01 PM

2

*1FaastC10* · 09-09-2003, 10:01 PM

3

*1FaastC10* · 09-09-2003, 10:02 PM

BTW, these are on my 86 C10, i'mm assuming some of them have to do with the AC, cruise control, or ESC systems.

Prerunner1982 · 09-09-2003, 10:18 PM

jeremy, cant figure out where the 1 and 3 pic are in relation to your engine. the 2nd pic however is of the vac. connection, i believe they may be temp operated, hence the connector on the intake and waterneck, i have done away with all but the important vac. hoses. i replaced my waterneck and capped off the rest of the ports.

Prerunner1982 · 09-09-2003, 10:21 PM

ok i looked at the 3rd pic alittle harder and it appears to be on the firewall, i have asked about the same thing that you have circled, except i have 2, one on each side. from what mike says they are for the trans, lock up torque converter maybe? if you only have one, it maybe for something else.. trace the vac. hose.....

**swervin ervin** · 09-10-2003, 12:01 AM

Damn Jeremy, sure is some sucky pics.

I'm not sure what they are, except for number 2. This is a TVS (thermal vacuum switch). This is too route vacuum to whatever is hooked up to it. The way it works is no vacuum until the engine temps are around 160 degrees. Say the TC is hooked to it. This means the the tranny won't lockup until the engine is around 160. Same thing with anything hooked to it. My truck came stock with two, a black one in the intake coolant passage and the gray one in the thermostat housing.

If number one and two are on the firewall, the one on the firewall behind the brake booster is the low vac switch for the TC clutch power.

The one on the passenger side is the tip in vacuum switch. On LE9 engine equipped vehicles with automatic transmission a "tip in" vacuum switch is used. Its function is to provide a momentary contact closure (signal) to the ESC controller during a throttle "tip in" condition which then briefly retards spark timing to minimize knock. The switch contacts are normally open under steady engine vacuum conditions including no vacuum, and all brief increasing vacuum conditions. Basically the switch closes only during rapidly decreasing vacuum conditions such as that encountered on rapid throttle operation.

*1FaastC10* · 09-10-2003, 08:38 AM

sorry for the sucky pics, but someone decided they needed my digital camera more than me.

#1 is on the firewall right behind the booster

#2 is pretty much an obvious water neck / intake

#3 is on a bracket over the passenger side valve cover.

pretty much these are all ESC/TCC related items then? i've already eliminated teh ESC distributor, and im planning on putting a pre-smog 'Jet on it, along with a Edelbrock intake. i'll do some more snooping around, but if that's all it is, its going away. A) clean up the engine bay, and B) make things easier to work on / tweak.

**swervin ervin** · 09-10-2003, 04:59 PM

Ok, so I'm right about the low vac switch, and the TVS. The one on the passenger valve cover is the EGR bleed solenoid. I don't have a clue what it does exactly, but it is tied into the tranny somehow. The only thing I could find out is it has something to do with the EGR not working when the tranny is locked, I think. If you remove this wiring, your tranny won't lockup. I know because I did it. My 700R4 didn't lockup when I first got my truck and after much troubleshooting, I couldn't find out why. I tried everything. Replaced pressure switches, soleniod, low vac switch, etc. Never could get it to work. I finally wired it up like the article I have. But I got rid of some of the wire mess.

*1FaastC10* · 09-10-2003, 08:40 PM

Mike, i was planning on using the article and wiring mine up teh same way you did. i had a customer when i was working at the dealership who had a van that someone hacked everything out of it (literally hacked, not removing like i'm doing) i sent him the link to your website, he made the mods to his van, and it worked perfectly.

*1FaastC10* · 09-10-2003, 09:52 PM

ok, now i'm completely ESC free, but i hav ea rather large gaping hole in my firewall. what do i use to cover it?

*1FaastC10* · 09-15-2003, 08:08 PM

bringing this thread back from the dead...

after doing a little more digging today, i noticed that the piece in #3 has a blue wire going to it from the fuse block area inside the cab. is that one of the wires i need to rewire the lockup?

09-09-2003, 10:18 PM	#5
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	jeremy, cant figure out where the 1 and 3 pic are in relation to your engine. the 2nd pic however is of the vac. connection, i believe they may be temp operated, hence the connector on the intake and waterneck, i have done away with all but the important vac. hoses. i replaced my waterneck and capped off the rest of the ports. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

09-09-2003, 10:21 PM	#6
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	ok i looked at the 3rd pic alittle harder and it appears to be on the firewall, i have asked about the same thing that you have circled, except i have 2, one on each side. from what mike says they are for the trans, lock up torque converter maybe? if you only have one, it maybe for something else.. trace the vac. hose..... __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

09-10-2003, 12:01 AM	#7
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Damn Jeremy, sure is some sucky pics. I'm not sure what they are, except for number 2. This is a TVS (thermal vacuum switch). This is too route vacuum to whatever is hooked up to it. The way it works is no vacuum until the engine temps are around 160 degrees. Say the TC is hooked to it. This means the the tranny won't lockup until the engine is around 160. Same thing with anything hooked to it. My truck came stock with two, a black one in the intake coolant passage and the gray one in the thermostat housing. If number one and two are on the firewall, the one on the firewall behind the brake booster is the low vac switch for the TC clutch power. The one on the passenger side is the tip in vacuum switch. On LE9 engine equipped vehicles with automatic transmission a "tip in" vacuum switch is used. Its function is to provide a momentary contact closure (signal) to the ESC controller during a throttle "tip in" condition which then briefly retards spark timing to minimize knock. The switch contacts are normally open under steady engine vacuum conditions including no vacuum, and all brief increasing vacuum conditions. Basically the switch closes only during rapidly decreasing vacuum conditions such as that encountered on rapid throttle operation. __________________ Mike 1985 Chevy C-10

09-09-2003, 09:58 PM	#1
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	need help with parts ID i need to know what these parts do, and what they are. hopefully you guys can help...

09-09-2003, 10:01 PM	#2
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	2

09-09-2003, 10:02 PM	#4
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	BTW, these are on my 86 C10, i'mm assuming some of them have to do with the AC, cruise control, or ESC systems.

09-10-2003, 08:38 AM	#8
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	sorry for the sucky pics, but someone decided they needed my digital camera more than me. #1 is on the firewall right behind the booster #2 is pretty much an obvious water neck / intake #3 is on a bracket over the passenger side valve cover. pretty much these are all ESC/TCC related items then? i've already eliminated teh ESC distributor, and im planning on putting a pre-smog 'Jet on it, along with a Edelbrock intake. i'll do some more snooping around, but if that's all it is, its going away. A) clean up the engine bay, and B) make things easier to work on / tweak.

09-10-2003, 04:59 PM	#9
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Ok, so I'm right about the low vac switch, and the TVS. The one on the passenger valve cover is the EGR bleed solenoid. I don't have a clue what it does exactly, but it is tied into the tranny somehow. The only thing I could find out is it has something to do with the EGR not working when the tranny is locked, I think. If you remove this wiring, your tranny won't lockup. I know because I did it. My 700R4 didn't lockup when I first got my truck and after much troubleshooting, I couldn't find out why. I tried everything. Replaced pressure switches, soleniod, low vac switch, etc. Never could get it to work. I finally wired it up like the article I have. But I got rid of some of the wire mess.

09-10-2003, 08:40 PM	#10
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	Mike, i was planning on using the article and wiring mine up teh same way you did. i had a customer when i was working at the dealership who had a van that someone hacked everything out of it (literally hacked, not removing like i'm doing) i sent him the link to your website, he made the mods to his van, and it worked perfectly.

09-10-2003, 09:52 PM	#11
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	ok, now i'm completely ESC free, but i hav ea rather large gaping hole in my firewall. what do i use to cover it?

09-15-2003, 08:08 PM	#12
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,399	bringing this thread back from the dead... after doing a little more digging today, i noticed that the piece in #3 has a blue wire going to it from the fuse block area inside the cab. is that one of the wires i need to rewire the lockup?



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