Soldering PCM Terminals
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Soldering PCM Terminals Hi guys,
I am putting a 5.3 Vortec engine in my '85 S10. Since there is limited space for fuse boxes and wiring under the hood and to get a cleaner look I am putting the PCM and Tac module inside the cab, so I must pass all the wires through the firewall. I have 2 Delphi HES connectors that have 47 cavities each. These connectors are for 20-22 gauge wires which make the task that much more difficult. I will have 80 plus ( really 160+ ) connections at the firewall and then all the connections at the PCM. My question is should I crimp and solder, or only crimp? If I do solder do you use just rosin core solder alone or rosin core paste with it. I know you never solder 02 sensor wires but how about the rest. I don't want these small wires to work their way out of the connector as I driving and cause problems. I know if you ask any electrical engineer he would say a good crimp is better, but I don't have one of those $200 Delphi crimpers they recommend.
Any input or opinion would be appreciated. Have a good day.
I am putting a 5.3 Vortec engine in my '85 S10. Since there is limited space for fuse boxes and wiring under the hood and to get a cleaner look I am putting the PCM and Tac module inside the cab, so I must pass all the wires through the firewall. I have 2 Delphi HES connectors that have 47 cavities each. These connectors are for 20-22 gauge wires which make the task that much more difficult. I will have 80 plus ( really 160+ ) connections at the firewall and then all the connections at the PCM. My question is should I crimp and solder, or only crimp? If I do solder do you use just rosin core solder alone or rosin core paste with it. I know you never solder 02 sensor wires but how about the rest. I don't want these small wires to work their way out of the connector as I driving and cause problems. I know if you ask any electrical engineer he would say a good crimp is better, but I don't have one of those $200 Delphi crimpers they recommend.
Any input or opinion would be appreciated. Have a good day.
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
Crimp. All of the factory PCM terminals are just crimpled. All of the wires going into all of the sensor connectors are just crimped. A good crimped will be much cleaner.
You don't need expensive crimpers. I use a $30 pair from Home Depot.
You don't need expensive crimpers. I use a $30 pair from Home Depot.
What engine harness are you using or are you making one from scratch? If you are starting with a factory harness, you could simply extend the PCM connection to the length you need (I would solder and heat shrink, time consuming I know). In order to pass the harness through the firewall you can label every wire, depin them all from the PCM connectors and reconnect them after you pass the wires through the firewall.
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Thank you Joe Nova, I did get a cheap crimper online, but it only crimps the terminal and not the tabs that wrap around the insulation in one operation. If I am careful and patient that may be all I need. I will check out the Home Depot crimper and see if is any better than mine. I am too shakie to solder anyway. Have a good day.
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Hi ss.slpls1, I am using the harness out of the donor vehicle (2003 Suburban) and must cut the wires at the firewall connectors pass-thru, it is a twist lock deal that will make removing the engine, or cab during the build much easier. I read so much about solder or no solder and resistance in the circuit if you do solder. Soldering would probably be stronger if you do it right, but the resistance factor bothers me. These wires are 20-22 ga. and it would be very easy to damage the insulation if soldered. I looked at Painless and other custom harnesses, but they don't make what I really want. Thank you, have a good day.
TECH Fanatic
Joined: Dec 2017
Posts: 1,467
Likes: 265
From: Bossier City, Louisiana
I'd not re-pin and re-crimp. I am thinking about cutting each wire in the middle and then adding wire to gain the length I need to reach the passenger compartment - behind the glove box or under the passenger seat most likely for my El Camino. After the cuts, its easy to pass all wires through a small hole in the firewall with a grommet.
Adding wire in the middle of the run keeps the wiring diagram colors the same at the PCM connectors for future owners - way less confusing to them about what you did.
Rick
Adding wire in the middle of the run keeps the wiring diagram colors the same at the PCM connectors for future owners - way less confusing to them about what you did.
Rick
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Hi Rick, thank you for your input. Your suggestion is just about what I want to do. I have each sensor with the original connector and the harness all ready to go. Each harness has ample wire to reach the PCM with no splicing, but I tried several ways of trying to get the harnesses with the connectors through the firewall in one piece with the thought of future engine removals. If I have to remove the engine for any reason (which I had to do many times already) you would have to disconnect each harness at the sensors and feed them back through the firewall opening, the hole would have to be at least 2 1/2" ( which I cut out and filled it back in) and that would be very time consuming and sealing it properly would be difficult. The Delphi HES connectors may be just the ticket, they are small, have a male, female end and have a twist lock connection. If you get a chance just look up Delphi HES connectors on the Delphi website and Waytek has all the info and terminals. It is going to be a tedious job that requires infinite patience, a good eye to read the numbers on the connector and checking each circuit several times to make sure they are in the right cavity. Have a good day.
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Be careful if you solder. I thought that was the way to go, but the solder can soak right up to the tip and fill it so it can't plug in.
I bought a crimper that does three size crimps along with 2 weather seal crimps. For the ecu terminals I start with the middle and then the smallest crimp in the tool.
I bought a crimper that does three size crimps along with 2 weather seal crimps. For the ecu terminals I start with the middle and then the smallest crimp in the tool.
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TECH Apprentice
Joined: Sep 2006
Posts: 328
Likes: 3
I'd not re-pin and re-crimp. I am thinking about cutting each wire in the middle and then adding wire to gain the length I need to reach the passenger compartment - behind the glove box or under the passenger seat most likely for my El Camino. After the cuts, its easy to pass all wires through a small hole in the firewall with a grommet.
Adding wire in the middle of the run keeps the wiring diagram colors the same at the PCM connectors for future owners - way less confusing to them about what you did.
Rick
Adding wire in the middle of the run keeps the wiring diagram colors the same at the PCM connectors for future owners - way less confusing to them about what you did.
Rick
just did my new harness . it was easier to just crimp and solder new pins than make 60 lineman splices. just make sure to get a pack of both 18awg pins and some 20-22awg. I bought 50 of each and that was plenty to do my whole harness.
I know a crimp is better than a solder joint, but the cheapy crimpers I used was letting wire pull out on a couple of test crimps.
I know a crimp is better than a solder joint, but the cheapy crimpers I used was letting wire pull out on a couple of test crimps.
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Crimpers Be careful if you solder. I thought that was the way to go, but the solder can soak right up to the tip and fill it so it can't plug in.
I bought a crimper that does three size crimps along with 2 weather seal crimps. For the ecu terminals I start with the middle and then the smallest crimp in the tool.
I bought a crimper that does three size crimps along with 2 weather seal crimps. For the ecu terminals I start with the middle and then the smallest crimp in the tool.
NOT To Solder Hi Kruzer, NO : DO NOT SOLDER, the solder will travel into the copper wire BREAKING the connection when under vibration.
READ the "how-to" in the Delphi/Packard sales book.
Next, my method is to use a Firewall Boot that opens to allow the cable to be inside the boot, then cut the required boot sized hole in the firewall.
The end look is clean.
I use the Waytec Crimper @ $85.00
Lance
READ the "how-to" in the Delphi/Packard sales book.
Next, my method is to use a Firewall Boot that opens to allow the cable to be inside the boot, then cut the required boot sized hole in the firewall.
The end look is clean.
I use the Waytec Crimper @ $85.00
Lance
Thread Starter
Staging Lane
Joined: Aug 2013
Posts: 63
Likes: 2
Crimpers Hi Pantera EFI, the more I hear about no solder the more I believe you are right. Would you know the part number of the Waytek crimper? I looked through the catalog for crimpers and they had so many and didn't find any ratcheting crimper in that price range, but they had one (Sargent 3107 DTCT Ratchet Crimping Tool for Deutsch Terminals) that crimped wires from 20-12 ga.The wires on my PCM harness may be as small as 22 ga. and that is right on the border line. This crimper lists for $42.25, is this the one you may be talking about? When I finish my wire crimping I may have 200 crimps and I don't want any problems with faulty crimps. I would appreciate if looked for the part number and posted it. Thank you, have a good day.
