Author Topic: Cold Start Relay  (Read 5170 times)

hill

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Cold Start Relay
« on: December 12, 2007, 12:32:33 »
Does anyone have a a spare or loaner cold start relay? I hate to purchase new for diagnosis by parts swapping. :)

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

jeffc280sl

  • Guest
Re: Cold Start Relay
« Reply #1 on: December 12, 2007, 13:13:04 »
Hill,

It's a standard Bosch type relay avaialble at any auto parts store.  They are $5.  I took the silver relay cover apart and put the new relay inside it and soldered the wires to the right leads.  It looks like the old relay but has a new relay hidden inside.  Job done.

Jeff C.
1970 280SL 4-speed

hill

  • Guest
Re: Cold Start Relay
« Reply #2 on: December 12, 2007, 14:44:12 »
quote:
Originally posted by jeffc280sl

Hill,

It's a standard Bosch type relay avaialble at any auto parts store.  They are $5.  I took the silver relay cover apart and put the new relay inside it and soldered the wires to the right leads.  It looks like the old relay but has a new relay hidden inside.  Job done.

Jeff C.
1970 280SL 4-speed



Thanks I'll give it a try this weekend.

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

jeffc280sl

  • Guest
Re: Cold Start Relay
« Reply #3 on: December 12, 2007, 17:06:56 »
Glad to help.  The standard relay has 4 terminals and they are labeled 30, 85, 86 and 87.  I'm almost positive the old relay is labeled the same way.  

Forgot to mention that you may just need to clean the contacts in the old relay. Here is a pic of what the inside looks like.  

A 12V lamp with leads is a good visual indicator the relay is or is not working.  If you take the lamp leads and connect one side to ground and the other one to the cold start valve terminal you will see the lamp light as you start the car if the relay is working.

Download Attachment: Cold Start Relay 1.jpg
44.12 KB

Jeff C.
1970 280SL 4-speed

hands_aus

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Re: Cold Start Relay
« Reply #4 on: December 14, 2007, 05:21:15 »
quote:
Originally posted by jeffc280sl

Glad to help.  The standard relay has 4 terminals and they are labeled 30, 85, 86 and 87.  I'm almost positive the old relay is labeled the same way.  

Forgot to mention that you may just need to clean the contacts in the old relay. Here is a pic of what the inside looks like.  

A 12V lamp with leads is a good visual indicator the relay is or is not working.  If you take the lamp leads and connect one side to ground and the other one to the cold start valve terminal you will see the lamp light as you start the car if the relay is working.

Download Attachment: Cold Start Relay 1.jpg
44.12 KB

Jeff C.
1970 280SL 4-speed


Interestingly, if you watch the test light during start up you can also determine that the Thermo Time Switch is working properly.
The test light should go off after a maximum of 17 seconds (depending how cold it is).

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

WILL2614

  • Guest
Re: Cold Start Relay
« Reply #5 on: July 31, 2011, 17:16:27 »
I HAVE  A 64 230 SL    THESE RELAYS  ARE  4 PRONG     ARE THEY ALL THE SAME    THESE COLD START RELAYS  HAVE A  RESISTOR INSIDE  I THINK

jeffc280sl

  • Guest
Re: Cold Start Relay
« Reply #6 on: August 01, 2011, 01:54:40 »
It's hard to see in the pic but the 280SL relay has 4 pins as well.  The wiring diagram for the 230SL and 280SL are identicle as far as this relay goes.