• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Under dash wiring problem-BJ7

robert_ellison

Jedi Trainee
Offline
Am running into a wiring problem under dash- I have three heavier wires colored brown with blue coming out of the harness. I find no reference to this color combination in the wiring diagrams I have. however, when I connected the wiring 25 years ago I hooked one of these wires up to my starter switch. If this is correct, fine but what about the other 2. If this in not correct please advise.

Anyone having another diagram other than those shown in Haynes & Bentley manuals for early& later cars I would appreciate a copy to refer to.

Thanks much
 
Hi I've just checked on austinhealeys.com and it has a download for wiring diagram,showing brown blue going to ignition switch,lighting switch and voltage regulator/cut out,hope this helps
 
Hmmm, I didn't think they used a brown/blue wire after the BN4.
 
Thanks for the info. Now my only problem is determining which wire goes where.

Anyone have any tips as to the best method to go about it? I would hate to burn up my harness. I'm worried enough about doing that due to the inconsistencies in the color coding I have encountered to date.

2 of the wires connect to the lighting switch, one of them terminating in the cut out, the other connects to the starter switch.
 
I hate to venture a guess since it may not be a stock harness. If you look at the wiring diagram in the manual under section "N", you see one wire connecting to A1 of the regulator. 2 wires (maybe on the same spade) connect to "A" on the light switch. Finally, one attaches to the keyed ignition switch. Basically, the light switch is a buss stop. One wire reg-to-light, then light-to-ignit.
 
robert_ellison said:
what does buss stop mean?
I guess a failed attempt at humor. A buss (as opposed to a bus) being a distribution block. My buss stop being a trip from the regulator to the ignition switch with a stopover at the light switch where the electrons have to change lines.
 
so if that is the case does it matter which of the 3 wires I connect to what?( voltage regulator, light switch, starter switch?)

And, if it does matter, my question still is, how to I tell which goes to what?
 
Shouldn't make any difference as they are a way of connecting these components together, only the lengths could govern where physically you can connect them
 
robert_ellison said:
so if that is the case does it matter which of the 3 wires I connect to what?( voltage regulator, light switch, starter switch?)-----NO!!

How do I tell which goes to what?--- See Mike's response above.---Keoke
 
robert_ellison said:
so if that is the case does it matter which of the 3 wires I connect to what?( voltage regulator, light switch, starter switch?)

And, if it does matter, my question still is, how to I tell which goes to what?
Hi Robert,
As Mike says, the harness should limit the way the wires get hoked up. The two wires that come out of the harness at the same point should go the the light switch. The brown/blue wire that exits the harness by itself should go to the ignition switch. If you want to check this, take an ohm meter and connect it to the wire near the ignition switch, then test the two wires. The one with no resistance is the other end of the ignition wire. The remaining wire (that had resistance) can be checked the same way with the wire at the regulator. Here are a couple simplified diagrams. Figure A sounds like what you have in your car. Figure B is the wiring I believe would be correct for your car. In Figure B, you'd only have two brown wires under your dash, not three.
 

Attachments

  • 17093.jpg
    17093.jpg
    35.2 KB · Views: 175
Back
Top