Soldering Ignition Terminals

Gotta love that wiring . . .
Post Reply
User avatar
tartan18
Posts: 505
Joined: Sun Mar 13, 2011 10:58 pm
Your car is a: 1975 Fiat 124 Spider
Location: Lebanon, Oregon

Soldering Ignition Terminals

Post by tartan18 »

Has anyone used "liquid solder" to attach the ignition wires to the switch terminals (upper right corner of the picture)? Is there an alternative to using conventional solder? I am not crazy about laying upside down under the dash with a soldering gun and dripping solder. :oops: While I have tightened the female crimp-on fasteners they do loosen over time.

Image[/URL]
Jim MacKenzie
1975 Fiat Spider
Finest Italian Automotive Technology
User avatar
JEEPER
Posts: 136
Joined: Tue Aug 16, 2011 6:34 pm
Your car is a: 1979 SPIDER
Location: SANDUSKY OHIO

Re: Soldering Ignition Terminals

Post by JEEPER »

The terminals are not made to solder. You may damage the switch by applying heat. Liquid solder isn't the answer. I would buy new spade connectors that fit and solder them to the wires and push them on. Spade connectors usually don't loosen up unless you push them on and off several times. Vibration shouldn't be an issue either unless they are worn ,bent or defective.
User avatar
RRoller123
Patron 2020
Patron 2020
Posts: 8179
Joined: Sun Nov 13, 2011 2:04 pm
Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Soldering Ignition Terminals

Post by RRoller123 »

Agreed. The terminals are quite heavy on the Ignition Switch, and the amount of heat needed to solder them will likely compromise the internal workings. Stick with the push-on connectors, with the wires soldered to them if you wish.
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
spider2081
Patron 2024
Patron 2024
Posts: 3015
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: Soldering Ignition Terminals

Post by spider2081 »

To the best of my knowledge most push on terminals are of the crimp style with a plastic or nylon jacket covering the area where the crimp is to be made. Heating these terminals to solder temps would cause them to out-gas and contaminate the solder. Also push type terminals are manufactured to have a spring type tension in their manufacturing process. Heat causes them to expand (open) and lose their strength. It is current flowing through your terminals that heated them and caused them to loosen up in the first place.
You would need to be sure you purchase solder push terminals if you want to solder the wires to the terminals.
Good quality crimp terminals are better than solder terminals in almost every application.
User avatar
RRoller123
Patron 2020
Patron 2020
Posts: 8179
Joined: Sun Nov 13, 2011 2:04 pm
Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Soldering Ignition Terminals

Post by RRoller123 »

Agreed, you definitely need to use terminals that were designed to be soldered if you are going that way.
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
htchevyii
Patron 2022
Patron 2022
Posts: 1807
Joined: Thu Jan 17, 2008 9:31 pm
Your car is a: 1982 Spider hers 1972 Spider his
Location: Hydesville, CA (NorCal)

Re: Soldering Ignition Terminals

Post by htchevyii »

I soldered mine, but was very careful not to use too much heat. Mine had a pigtail so I was able to do it on the bench, (my OE switch was soldered).
Trey
Image
1982 SPIDER 2000, 1964 CHEVYII, 1969 Chevy Nova, 2005 DODGE RAM, 1988 Jeep Comanche
1972 Spider, 78 Spider rat racer 57 f-100,
User avatar
tartan18
Posts: 505
Joined: Sun Mar 13, 2011 10:58 pm
Your car is a: 1975 Fiat 124 Spider
Location: Lebanon, Oregon

Re: Soldering Ignition Terminals

Post by tartan18 »

Thank you to all who have advised on this issue. I appreciate all your suggestions.
Jim MacKenzie
1975 Fiat Spider
Finest Italian Automotive Technology
spider2081
Patron 2024
Patron 2024
Posts: 3015
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: Soldering Ignition Terminals

Post by spider2081 »

You might try contacting

Devcon
30 Endicott St.
Danvers, MA, 01923
USA

They market a line of liquid type solders for different applications. It is interesting, one short coming could be the cure time is in the area of 24-72 hours.

Soldering is much more difficult than many realize. The molecular bond between solder and copper takes place in the area of 350-450 degrees F. All the parts have to be this temp for the proper bonding called "wetting action" to occur. When this temperature is not reached a "cold solder" connection is made. The parts may appear to be physically stuck together but when current flows through the connection heat is generated and in time it can become intermittent. Nylon which is used in the manufacturing of so many after market electrical parts turns to a liquid at 450 degrees. Nylon can become pliable at lower temperatures. For this reason soldering anything molded in nylon is risky at best. Even using some sealing heat shrink tubing can cause nylon to deform.

I like your question about liquid solder and will be looking into some of its applications.
Post Reply