Jump to content

B61 Defroster Circuit Diagram

Recommended Posts

I am looking into replacing a switch for the defroster circuit on a B series.  I know the original switch was a 1 ohm 3 position switch, but need to see a circuit diagram to find a suitable replacement.  Does anyone know where I can find one for the defroster circuit?

Link to post
Share on other sites

My B61 the switch for the heater fan is the same switch for the defroster fan. Yours different?

“Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’”


Link to post
Share on other sites

A switch on the left side of my dash was replaced with a toggle switch, but I saw that some like mine had an extra hole with a knob I couldn't identify.  I found out through researching various pictures of B series that there was a defroster switch in that hole.  I will get the information from the Mack Museum to find out more about the switch.  Not 100% sure it originally came on my truck.  Even if it didn't, I will pass the knowledge onto others.  It is my goal to return my truck with some minor upgrades to as close to original as possible.  Always fun to learn something new.


Edited by 58GreenMackB
  • Like 1
Link to post
Share on other sites
  • 4 weeks later...

only the B series with the bigger heater with separate defroster fan had the switch and most i have seen were back wired right off the heater switch. i don't think there was a separate circuit for the defroster.


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...