I found it like this...
My 1993 Volvo wagon had some Bosch relays that began to act flakey. The overdrive in the auto trans would click off intermittently, annoying on the highway. The cause was cracking solder joints around the relay pins on the circuit board. Reflowing the solder fixed the issue. It may have been because they had switched to lead free solder, I'm not sure when that happened, but the heat from the relay would cause the pins to expand and contract and eventually a hairline crack would encircle the pin and break the electrical flow. I reflowed all the solder on all the relays I could find. I plan to do the same for all the relays I can open in my 2800CS when I get under the dash.The printed circuit board is nice, when electronic were discrete and could be fixed.
A 240 Wagon?My 1993 Volvo wagon had some Bosch relays that began to act flakey. The overdrive in the auto trans would click off intermittently, annoying on the highway. The cause was cracking solder joints around the relay pins on the circuit board. Reflowing the solder fixed the issue. It may have been because they had switched to lead free solder, I'm not sure when that happened, but the heat from the relay would cause the pins to expand and contract and eventually a hairline crack would encircle the pin and break the electrical flow. I reflowed all the solder on all the relays I could find. I plan to do the same for all the relays I can open in my 2800CS when I get under the dash.
That's right. I need to see how the copper piece was going...I'm wondering if alprada70 would like to know where the loose copper piece goes inside the relay enclosure. I haven't had one of these apart, but I suspect it has come loose from the coil part of the relay in the center of the board. There's bound to be a spring mechanism involved somehow and that may be missing. If parts are missing or damaged, a replacement relay may be needed.
I had the same problem with the wiper motor on a 98 Silverado. Sometimes it worked, sometimes it didn't (when it started to rain).My 1993 Volvo wagon had some Bosch relays that began to act flakey. The overdrive in the auto trans would click off intermittently, annoying on the highway. The cause was cracking solder joints around the relay pins on the circuit board. Reflowing the solder fixed the issue. It may have been because they had switched to lead free solder, I'm not sure when that happened, but the heat from the relay would cause the pins to expand and contract and eventually a hairline crack would encircle the pin and break the electrical flow. I reflowed all the solder on all the relays I could find. I plan to do the same for all the relays I can open in my 2800CS when I get under the dash.
No, a 940 wagon. I actually had two '93 wagons, identical except for the paint colors, red then white. They both had the aforementioned relay issue, failing plastic side tanks on the radiators, inop AC, and leaking heater boxes. None of those issues were unexpected for the age of the cars. The bodies are zinc plated, at least up to window level, so rust wasn't an issue. Easy to service and pretty dependable. Carried a lot of stuff in them. Best seats in any car I've owned. I bought them well used and put 100K on each one. Only sold them because I was moving to, and then from Hawaii.A 240 Wagon?
Yes solder joints could be affected by the thermal cycle or bad joint to start with. The lead free ROHS mandate from Europe was around 2003 I recall.