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Technical => Electrical Tech => Topic started by: booksix on June 03, 2009, 06:17:53 PM

Title: Autolamp relays ground through mounting tab?
Post by: booksix on June 03, 2009, 06:17:53 PM
This topic came up in my want ad; about the autolamp relays using the mounting tab/relay tree for grounds.  The evtm and my mulitmeter tell me otherwise...  Do these need to be grounded through their cases?
Title: Autolamp relays ground through mounting tab?
Post by: softtouch on June 03, 2009, 10:21:45 PM
Quote from: booksix;275738
This topic came up in my want ad; about the autolamp relays using the mounting tab/relay tree for grounds.  The evtm and my mulitmeter tell me otherwise...  Do these need to be grounded through their cases?

84 used one DPST relay and the ground for the coil is the through the mounting hardware.
In 85 they changed to two SPST relays with the coils grounded through the sockets.
Title: Autolamp relays ground through mounting tab?
Post by: softtouch on June 03, 2009, 11:15:07 PM
OK I just read your parts wanted thread.
The third relay is the auto-dimmer relay. It is a SPDT and is grounded through the socket.
Title: Autolamp relays ground through mounting tab?
Post by: booksix on June 04, 2009, 04:32:44 PM
Ok, the one I don't actually use.  Thanks!  This confirms my 2nd autolamp relay is indeed bad!
Title: Autolamp relays ground through mounting tab?
Post by: softtouch on June 04, 2009, 05:39:14 PM
Quote from: booksix;275890
Ok, the one I don't actually use.  Thanks!  This confirms my 2nd autolamp relay is indeed bad!

With the dimmer feature turned off you still use the relay. The multifunction switch will operate the relay.
Title: Autolamp relays ground through mounting tab?
Post by: booksix on June 04, 2009, 08:17:32 PM
Ok, I was actually wondering about that (when my high beams started acting funny).  In that case, I'll need to get it grounded; is there way other than the specialized clips?  And why bother with this setup, why wouldn't they have just used a relay with a pinned ground?
Title: Autolamp relays ground through mounting tab?
Post by: booksix on June 04, 2009, 09:20:59 PM
I just got home from a 25 min drive (autolamp on) and I noticed the 3 relays are fairly warm to the touch.  Is this normal heat from the coil?
Title: Autolamp relays ground through mounting tab?
Post by: softtouch on June 04, 2009, 11:34:34 PM
Quote from: booksix;275920
Ok, I was actually wondering about that (when my high beams started acting funny).  In that case, I'll need to get it grounded; is there way other than the specialized clips?  And why bother with this setup, why wouldn't they have just used a relay with a pinned ground?

Only the earlier system that had just one relay needed the chassis ground through the mounting clip.
That is a double pole (two sets of contacts) relay.
This does not apply to you.
Title: Autolamp relays ground through mounting tab?
Post by: booksix on June 05, 2009, 01:06:19 AM
Sorry, I must have misread your earlier post.  Thanks