7 Electrical switch & relay parts are listed for the 1978 MG MGB, in 4 part types, covering the 1.8L L4 engine. Each one has a brand, a manufacturer part number and notes that say where it fits.
On the 1978 MG MGB, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. 6 parts of the 7 listed are Radiator Fan Switch (3 parts), Fuel Pump Cutoff Switch (2 parts) and Ignition Starter Switch (1 part). The other 1 part type covers the remaining 1 part.
The 1978 MG MGB came with a single engine, the 1.8L L4, and every part is verified against it.
5 brands supply electrical switch & relay parts for the 1978 MG MGB, led by STANDARD MOTOR PRODUCTS (2 parts), ÜRO PARTS (2 parts) and ACDELCO (1 part), plus 2 more brands.
Each part number listed for the 1978 MG MGB opens a page with every vehicle that part fits.
Fuel Pump Cutoff Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO | D1876D | 🇺🇸 US 🇨🇦 CA | Gold | View on Amazon |
| STANDARD MOTOR PRODUCTS | FV7 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the Fuel Pump Cutoff switches. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
2 Fuel Pump Cutoff Switch parts are listed for the 1978 MG MGB, from ACDELCO and STANDARD MOTOR PRODUCTS.
Part numbers include ACDELCO D1876D and STANDARD MOTOR PRODUCTS FV7.
Ignition Starter Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ÜRO PARTS | BHA5292 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the ignition switches that feed the starter circuit. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
This group shows a single part: ÜRO PARTS BHA5292.
Radiator Fan Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FACET | 75038 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| STANDARD MOTOR PRODUCTS | TS257 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| WELLS | 1S4431 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the Radiator Fan switches. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
3 Radiator Fan Switch parts are listed for the 1978 MG MGB, from FACET, STANDARD MOTOR PRODUCTS and WELLS.
Listed part numbers: FACET 75038, STANDARD MOTOR PRODUCTS TS257 and WELLS 1S4431.
Turn Signal Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ÜRO PARTS | AAU4995 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the combination / turn-signal switches. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
One part is listed for the 1978 MG MGB — ÜRO PARTS AAU4995.
Buying Electrical Switch & Relay Parts for a 1978 MG MGB
On this vehicle, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches.
- Confirm you have the 1.8L L4 engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Radiator Fan Switch and Fuel Pump Cutoff Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 1978 MG MGB?
Our catalog currently lists 7 electrical switch & relay parts for the 1978 MG MGB across 4 subcategories and 5 brands, covering the 1.8L L4 engine. Each part is matched to the engine(s) it fits.
What are the signs of electrical switch & relay problems on a 1978 MG MGB?
Common symptoms include accessories that work intermittently, a click without action, or one function dead while its fuse tests fine. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 1978 MG MGB was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 1978 MG MGB?
Every part on this page is matched to the 1.8L L4 engine. Then swap a suspect relay with an identical known-good one from the fuse box before buying — it is the fastest diagnostic there is. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 1978 MG MGB
Electrical Switch & Relay Parts for Other MG MGB Years
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