Paul Belluomini's Journal

This entry is dedicated to the electrical system, gauges and accessories of my MGB. I When I was stripping the car down I had removed the original main wiring harness, and dash harness. Both had been hacked into by the previous owner(s), they were in poor shape - dried out and brittle Since I was not going to go back to stock, I bit the bullet and ordered new harness from Moss, I managed to get one on sale. I decide to use the main harness #356-610 used on early 1974 MGBs and a rear harness #357-430 used on 1974 & 1975 MGBs. I was trying to eliminate as many possible electrical issues as possible while retaining the needed wiring for my purpose. I have the factory style trunk mounted fuel pump and the late 74-75 harness had the needed connections for this. I did modify the harness by removing the seat belt buzzer wiring before I installed the main harness.
I decided I wanted to back date the gauges to real chrome bezel MGB gauges while keeping the late style 6 gauge dashboard. I know some people would have used the early style 1963-67 style dash, but converting to one of those is a really major undertaking and they are hard to find in restorable condition. By mixing the earlier large tach and speedo gauges with the later 6 gauge style dash I could get the best of both. I really like the look of the older style gauges with the classic British lettering and markings. The original dash was totally shot due to sun exposure so I began searching for a replacement. I located one on ebay for $75 that had only one tiny crack on the right side near the glove box. I purchased the dash, cleaned it thoroughly, repaired the crack and the used interior plastic spray paint. This involved using their primer and the their black dash paint. It turned out looking like a new factory dash and the crack was now invisible. Using Ebay, I then purchased used Smiths speedo and tach from a 1967 MGB, the tach is also electric as earlier MGBs have mechanical tachs. These are the same diameter as the late style 1977-1980 gauges. The tach was sent out to Nissonger for conversion to negative ground and they updated the tach signal pickup to be more accurate and reliable. I also purchased really nice used fuel, temperature, and oil pressure gauges from Ebay. These were from a 1974 MGB and were cleaned and refurbished with new bezels and glass. Lastly, I purchase a new Smiths voltmeter to be used in place of the original clock which I did not want.
The harness was installed with the hardest part being the installation of the dash board part. Getting all those wires through the hole in the firewall into the interior was a real pain. The switches on the later style dash can be a real pain and are fragile. I sourced new hazard and heater fan switches. The headlight master switch was originally on a column switch which I did not like, also the horn was on the wiper/washer stalk which is not a good place in my opinion. I decided to back date my steering column to the 1975 configuration. This style fits the later body shell but has a horn mounted in the center of the steering wheel as is the norm. At this point I moved the headlight switch to the lower left hand dash position. To do this I bought a headlight switch from ebay - a Lucas SPB601 6GA3 - which is used on mark 4 Mini Coopers. This fit the dash opening and looks very similar to the factory switches. I also added a fog light switch in the spot where there is usually a blank and added the needed wiring for future use. I also back dated some small items such as the turn signal indicators to the 1973-75 style that have chrome trim and look much nicer that the late style indicators. I also removed the dash indicators for the brake failure , ignition, etc which looked tacky. I replaced those with the chrome trimmed, round indicator lights from a 1974 MGB. I had to make a plastic panel to fit these into the recess in the dash but it came out looking much better than the factory ones which always looked cheap and cheesy to me. Lastly I updated the headlights with a premade headlight wiring & relay harness to eliminate the problems with running the headlight power through the switches. I also added a set a set of euro style Lucas Halogen headlights, backed dated early MGB taillights and front turn/park signals, and LED taillight & brake light bulbs which are way brighter and safer than the factory bulbs. Overall it looks great and functions with no problems.