• 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

New electrical nightmare.............a radio

Share this page

F

fadler1

Member
Offline
Unbelievable. Just when I thought it was safe to drive again, I decided to put a radio into the MGB (1977). I wired to the clock circuit and the lighter circuit for power, put in new speakers and bought a new radio. Clean installation.....except: at first no sound even with full display on the radio. Then, I get up off the driver's seat and SOUND. Close the driver's door, no sound. Open the trunk, no sound. SO, great installation as long as you drive from the passenger seat with the driver's door open and the trunk closed. ANY IDEAS on this one? Everything else was fine prior to this. OH LUCAS. /ubbthreads/images/graemlins/eek.gif
 

Attachments

  • 93986-mgbcompressed2.JPG
    93986-mgbcompressed2.JPG
    27.8 KB · Views: 126
I think you got the interior light circuit not the lighter. There should be a circuit already there for the radio......
 
I used the white/green stripe wire for switched power (radio circuit) and ran the constant power wire directly to the cigar lighter.
The clock and cigar lighter are always on circuits. Why this combination? How do you want it to work when installed?
 
/ubbthreads/images/graemlins/savewave.gifFadler1
Since the main part of the radio contains an off/on control and the memory if contained requires constant power.Both power circuits can be connected to the same constant power on line.-FWIW---Keoke
 
[ QUOTE ]
Unbelievable. Just when I thought it was safe to drive again, I decided to put a radio into the MGB (1977). I wired to the clock circuit and the lighter circuit for power, put in new speakers and bought a new radio. Clean installation.....except: at first no sound even with full display on the radio. Then, I get up off the driver's seat and SOUND. Close the driver's door, no sound. Open the trunk, no sound. SO, great installation as long as you drive from the passenger seat with the driver's door open and the trunk closed. ANY IDEAS on this one? Everything else was fine prior to this. OH LUCAS. /ubbthreads/images/graemlins/eek.gif

[/ QUOTE ]

Well I don't like hearing this! /ubbthreads/images/graemlins/grin.gif My kids bought me a new radio/cd player for my B for Christmas, and my son's going to install it tomorrow!
 
Sportcars do not like radios. /ubbthreads/images/graemlins/devilgrin.gif
 
[ QUOTE ]
Sportcars do not like radios. /ubbthreads/images/graemlins/devilgrin.gif

[/ QUOTE ]
This sports car driver does! /ubbthreads/images/graemlins/driving.gif
 
Fadler1, you should have come off a green/brown wire right in the area of the radio or on later models a green/pink, if you can't find either anything dark green will work. Wayne
 
Ya know, ya'll are talking pink and brown and green and all these pretty-colored wires.

NOW I'm really scared. My son is color blind!!! /ubbthreads/images/graemlins/shocked.gif
 
2000;
"Anything Dark Green Will Work" If its dark green it is secondary switched power and you will dump the memory ever time you switch off.?--FWIW---Keoke /ubbthreads/images/graemlins/driving.gif
 
The saga continues.............cut the rear speaker wires that I put in the back behind the doors and now it works......sort of even with the door closed and the trunk open. Push down on the car on the driver side at the threshold and the radio sound goes off but not the radio display. OH LUCAS
 
Sounds like maybe a speaker is shorting it's self out killing the sound and allowing the head unit to still work. You may want to check the connections at the speakers and make sure they can not come in contact with an metal. You may have to rotate them. Ran into that same problem when installing new speakers into my xterra.

I just finished installing a new radio in my 75 b today including all new speaker wiring and everything works great. Used the White wire with the green stripe for main power and the purple wire from the cig lighter for the memory power. Every thing works great and the price of darkness didn't seem to object.
 
[ QUOTE ]
Sounds like maybe a speaker is shorting it's self out killing the sound and allowing the head unit to still work. You may want to check the connections at the speakers and make sure they can not come in contact with an metal. You may have to rotate them. Ran into that same problem when installing new speakers into my xterra.

I just finished installing a new radio in my 75 b today including all new speaker wiring and everything works great. Used the White wire with the green stripe for main power and the purple wire from the cig lighter for the memory power. Every thing works great and the price of darkness didn't seem to object.

[/ QUOTE ]
Sucks to be me.

Wanted 2 new speakers for my B. Kids decided I needed an entire new stereo. So I went yesterday, bought speakers, came home son & hubby decided 'professional radio installation' might not be a bad idea. /ubbthreads/images/graemlins/grin.gif That's when things went to L in a handbasket.

Kids bought stereo at Circuit City. Free installation. So I take it to the closest one. Kid says, "what sort of car?" I said, '75 MGB. He said, "We don't have books for German cars that old."

I left. Went to the next closest CC. Sat there 3 hours. Left with the top down and the radio thumping. 3 minutes later, no radio. Went back, they pulled the stereo, said it was bad. Called around, found a store that had that unit in stock. Had them hold it. Went today, spent 5 1/2 hours at Circuit City. STILL NO RADIO. The kid wanted to start from scratch since he didn't do the first install. Checked the wiring. All were good except a red wire (the one that is the 'on-off' power?) and a white (I think) one that should be the memory power.

Anyway, nightmare continues when I take it back to CC on Wednesday.

And all I wanted was two speakers to replace the crappy ones in the door. /ubbthreads/images/graemlins/grin.gif
 
Well the LBC gods had to smite me. Last night while driving the short rubber fuel line that connects the hard fuel line that crosses the firewall to the hard fuel line that goes up the left fender and connects to the carb cracked and starting leaking big time into the engine bay and the cockpit and I had a nice stream of gasoline pouring on my leg. So it looks like the B cost me a brand new pair of tennis shoes
 
Not to complicate things but I went ahead and put my own power supply in when I did the radio. Rather than use the existing power I ran a heavier line to the battery and use a 30amp automotive relay to switch the power on/off using a manual switch (which was already in the car), but the built-in switched power from the ignition would do the job too. I reasoned that the 30-ish year old wiring wasn't designed for the higher power draws of the modern radios, plus I wanted to install a small amp later.

All were good except the two power wires? Seems to me that's essentially the critical part of the install /ubbthreads/images/graemlins/laugh.gif Anyway - you might do better to buy a radio you know will fit and find a custom install shop that specializes in custom installs - not the typical big-box plug-in-and-run shops.

FWIW here's a page I did on my installation a couple of years ago: CLICK HERE
 
Back
Top