Using Solid State Relays on Cars

Want to restore, modify or repair your car’s electrical and/or electronic systems?
This handbook is a must-read that takes you from the basics of circuits right through to diagnosing and repairing complex electronic car systems.
• Perform basic and advanced fault diagnosis
• How to use a multimeter and even an oscilloscope on your car
• From basic circuits to understanding analog and digital signals
• Engine management systems explained
• How to use and fit low-cost electronic modules to your car
• Understanding electronic components like resistors and diodes
• Save money by doing your own fault-finding and repair
• Perfect for electronic modification, repair or restoration
Car Electrical & Electronic Systems is available from Veloce Publishing - bit.ly/2zoeTVh

[@mitchimal]

So good thank you

[@musicinspire1745]

I had to build my own DC solid state relays for my four Mercedes electric car battery modules. Each relay that I designed and built is rated for 56KW power handling capability. The modules themselves, at full charge, are 109.6 VDC and capable of 3C, which is 254 amps, but I will only be pulling 50-80 amps from each to drive my Outback inverters for my house during power outages. The market simply doesn't have solid state relays in the voltage range that I needed. I'm using two MOSFETs in parallel, each rated at 200V and 140A. That way the BMS can switch out of circuit any one of the modules that has either imbalanced cells, or is close to 80% depth of discharge in the Li-ion's.

[@JohnHodder]

Why not use contactors for this application? Sounds like a great project though

[@JohnHodder]

Great video. Cheers

[@genismorenosoldevila]

Very useful information, thank you for the video, keep going it seems you know a lot about automoviles and mechanics. Hope the chanel grows more.

[@NTECIreland]

Very informative and brilliant accent!

[@jackdale9249]

are there sources for the relays in the book ? we would like to replace all the plug in relays on our exotic cars w/ solid state versions ! information is difficult to come by ! thx for the video !

[@lyndenhazlehurst2333]

Hi trying to turn on a relay with feed from rev counter shift light so only low current at switch side not enough for normal relay thinking a solid state would take less to switch am I right

[@IkmalRusli]

Hi I 've used solid state relay for my car dome light trigger, as we know car dome light is negative trigger. so I connect pin 3 to continuous +12v and pin 4 to switched ground negative. When the pin 4 swithed to ground the relay work as expected it joint/closed pin 1 and 2, however once the pin 4 ground is switched off the relay is still closed. Any explanation or solution to this issue ?

[@mykl65]

Had read thru the pros/cons of SSR & one of it is voltage leakage after power off. Not much about 0.1mV but will this drain your car 12V battery over period of time when not in use?

[@krislton]

Why (in your air suspension switching control) do you also have a conventional type relay (blue logic level relay on pcb)? I'm assuming since they're shown together that they're used together but can't think of a logical reason for showing them together when the video is about SSR's or why you would want to use them together. (Not intended to sound so negative! Great video, I'm just intrigued).

[@yoancarlove7383]

I was mislead by this video. Turns out Fotek or Similar Triac SSRs don't support PWM. Was trying to use one for a fuel pump and it would just be ''ON'' no PWM action.

[@jonsimmons4150]

Im stunned noone in 2023 has drop in ssr that fit into standard relay positions in older cars. Several types of relays onboard, yet noone has marketed a 10 second to pull out/ drop in module to upgrade existing "dinosaur tech"

[@geoffkelland5606]

Comment

[@alexanderangelov7325]

Hello, I am sure, that you are making a mistake by showing the output side of the relay different polarity! The output side: terminals 1 & 2 are normally open. When the relay is energized and closing the output contacts there become the SAME POLARITY whatever the issue is! Contact of input is 3 & 4 (where 3 is positive and 4 is negative or ground as you are indicated) In one word your explanation is a big mess and I will never employ as a teacher! You will blow the whole world! Have a nice day! Alex

[@WayneMcKenzie]

I suspect the information given is for lay people not electronic technicians. Sometimes the obvious is obfuscated by correct technical explanation and makes it difficult for the DIY person to have a clear understanding as to what they are doing. For example, I am fitting a thermo fan to my car's radiator. I found this video straight to the point and very clear.

[@shanenortje1837]

No mistake. The output side must be shown as negative on the SSR. The negative sign is to symbolise which side the load (positive lead of consumer) goes onto. If you place the load on the wrong side the relay will not switch off due to the voltage present at the gate of the triac. A triac works in one direction of flow and serves as the electronic switch in the SSR.

[@John-rw9bv]

@@shanenortje1837 Whole point of the video was to describe exactly this, but some people swear they know best ¬.¬