New Member MGB

[Cottenmgb]

Hi,
I just purchased this 78 MGB. I owned several MGBs in the 70's and a 59 MGA. Fast forward to today..I got the car, drove it once and had a major brake problem. Also had the clutch cylinder and a leaking hose repaired. The dash lights are not working and I was told the electrical harness needs replacing. Wow! I didn't expect this kind of expense right away. I thought about just cutting my losses and selling it, but I may hang in there and try replacing the harness myself. I've been watching "how to" videos on harness and dashboard replacement. You may be laughing at this point at trying to make this a DIY project, but any tips would be greatly appreciated. Below is my 1975 B (with a much younger me) and the 1978 on the trailer in Orlando being shipped to me in South Carolina.

 

[BobHaskell]

I replaced the main harness in our '80 MGB - didn't replace the harness that went to the gearbox or to the rear of the car. Suggest that as you take the old harness out that you label every wire with what it was connected to - not just the item (windshield wiper motor), but also the terminal/post. Take lots of pictures showing how the harness is routed and connected to the bits. Keep the old harness laid out next to the car while you install the new.

 

[Cottenmgb]

Thanks Bob! I also plan on just replacing the front and dash harness.

 

[JPSmit]

Who told you the harness needed replacing? I took my harness out when I did my car and found a couple of burned/fused wires but, a careful repair plus a fuse on the dash lights plus bypassing the rheostat dash light dimmer plus a few relays on the headlights and horn and all works well. Even when I let the smoke out of the harness a couple of years ago it was still not a difficult fix. One step at a time and all will be well. Oh and welcome!

 

[Cottenmgb]

Who told you the harness needed replacing? I took my harness out when I did my car and found a couple of burned/fused wires but, a careful repair plus a fuse on the dash lights plus bypassing the rheostat dash light dimmer plus a few relays on the headlights and horn and all works well. Even when I let the smoke out of the harness a couple of years ago it was still not a difficult fix. One step at a time and all will be well. Oh and welcome!

Thanks for the welcome. The tech at my local MG shop told me the harness needs to be replaced. To get the dash lights working will cost 2,500.00. The full harness replace will be over 5,000.00. I can't spend that much so I have been thinking about doing it myself. If the lights, turn signals and other dash functions work with the current harness why does it need replacing for the dash lights to work?

 

[DrEntropy]

Harness can be found for $500~$600, Replacement in a "crash-pad" MGB can be a fiddle but if seats are out it can be done without removal of the dash. Color codes, diagram and LOTS of photos of the "before" wiring will help. Start at the instrument end. get a new firewall grommet, fit it to the harness before threading the wiring thru the bulkhead.

 

[Mickey Richaud]

Whether or not you decide to do it yourself, here's a link to a wiring diagram that's easy to follow. Just scroll down to your model year:

http://www.advanceautowire.com/mgb.pdf

 

[DrEntropy]

And one good source for the harness. Look for the year-appropriate one.

 

[Cottenmgb]

Harness can be found for $500~$600, Replacement in a "crash-pad" MGB can be a fiddle but if seats are out it can be done without removal of the dash. Color codes, diagram and LOTS of photos of the "before" wiring will help. Start at the instrument end. get a new firewall grommet, fit it to the harness before threading the wiring thru the bulkhead.

Thanks for the info!