Fujitsu M4099D While attempting to scan I get a Front lamp error. Any idea what could cause this? The bulbs and housing are installed correctly.

If the front lamp is correctly installed (take a look at the lamp carrier pictures) and all 8 possibilities from zone48 are OK,
then you have to check the cables.

At the front camera right side you see one wide black connector for the CCD data transfer cable and one grey plug for power.
Inside the CCD cable there are 40 coloured wires.

Power plug test:
Use a voltage meter to check the power. In some cases the soldering points at the PCA are broken or the plug pins are burnt.

CCD cable test:
Disconnect the CCD connector at the camera.
Disconnect the CCD connector at the scanner's backside at the junction board.
Screw off the metal cable clamps.
But the two connectors side by side.
Now use a resistor tester and measure from connector contact number 1 to contact number 1 at the other connector if there is a linkage. Then do the same with contacts number 2 and so on.
A lot of work but a must.
By a broken wire you will get no linkage.

In case you found broken wires you need a new cable.
Fujitsu part number: CA04315-F851
Fujitsu part name: CCD Cable

Good luck!

First, you didn't say whether the Front lamps are actually lit. I know that it is difficult to tell on this model unless you cheat the lamp interlock switch and fire up the unit into scan mode.
Front Lamps errors can also be generated by a loose front camera cable. There are no dedicated lamp detectors. The 4099 uses the camera's ccd's to detect if the lamps are burning. It is also possible, but less likely , that the lamp fuse on the main board (slides out from rear) is blown. (Fuse part number CA53004-0227).
From previous experience, there is probably a 95% chance that the issue if coming from a loose front camera cable. Not the kind of thing to get in and check unless you are service savy. I have had several calls that drove me nuts with this issue until I reseated that cable onto the camera.

The Fujitsu service manual list these possibilties :

a. Do the Front side lamps lite up when you attempt to scan?
b. Is the lamps correctly seated?
c. If the lamps don't light up, possible lamp inverter problem or fuse problem.
d. Is the glass surface and white sheet guide clean?
e. Are the connectors at the front camera ccd loose?
f. Is the power supply output normal?
g. Possible front camera failure.
h. Possible connections from camera to the Rom board problem.