A 4-amp fuse.
You could replace it with a 3A fuse. You should never replace a fuse with one which is rated higher.
The 4A fuse associated with the headlight auto dimmer circuit in a 1971 Lincoln Mark III is located in the main fuse box. For this vehicle, the fuse box is typically mounted behind a small panel in the glove compartment. Additionally, some circuit breakers related to lighting may be located to the right of the glove compartment area. If you are troubleshooting this system, having the shop manual for the 1971 Mark III would be highly beneficial as it provides detailed diagrams and component locations.
.044 in
(4a)2 or 16a2
4a*4a*4a = 64a3 cubic units
What is the additive inverse of -4a?
8
4a+2b+a
-4a.
A 4A T fuse, specifically in the context of automotive applications, is a type of automotive fuse rated for 4 amperes. The "T" designation indicates that it is a time-delay (or slow-blow) fuse, which means it can tolerate brief overloads without blowing, making it suitable for circuits with high inrush currents. These fuses are commonly used to protect sensitive electronic components in vehicles, ensuring reliable operation while preventing damage from electrical faults.
On the one Rendezvous I've ever worked on, it was in position 4A in the fuse panel which was located in the center console with the access door in the passenger side foot compartment.
The fuse protects the cable it is feeding therefore in UK upto 10A for 1.0mm cable, upto 15A for 1.5mm cable and upto 20A for 2.5mm cable. This is for installation type (solid core copper) cable not flex. In the UK and the rest of the EU (230V) 1 Kw load = 4A so 5A fuse should be OK. 2KW = 8A, 3KW = 12A so use 13A Fuse.