Mustang MonthlyHow To Tech Qa
Beyond The Basics - Vintage Tech Advice
In 2010 I purchased a 1973 Ford Mustang Mach 1. Upon getting it home, I discovered that the dash lights do not work with the exception of the turn signals and the high beam indicator. To try to resolve the issue, I have replaced the fuses in the fuse box, bulbs, headlight switch, printed circuit board on the back of the speedometer, and the voltage regulator that snaps onto the printed circuit board. All the lights on the outside of the car work when the headlight switch is on. Turning the headlight switch will also turn on the dome light inside the car. Recently, someone told me that the dash ground could be the problem. Can you confirm this, and tell me where this would be located or other possible solutions to the problem?
Via the Internet
The fact that you have working lights on the outside indicates that the headlight switch is powered correctly, therefore your problem has to be between the headlight switch and the dash cluster. The power runs through the headlight switch rheostat (which adjusts brightness) to the fuse box where there is a 4-amp fuse dedicated to the lighting circuit, and up to the dash cluster and other illuminated items, such as the radio and clock. The wires in question are light blue/red striped and can be checked using an ordinary 12-volt test light. The headlight switch must be pulled on so the illumination circuit is live during the tests.
Rotate the rheostat counter-clockwise. If the radio and other items illuminate normally, then the circuitry from the switch and fuse box is okay and your problem is isolated to the cluster itself. Check for power on the light blue and red wire at the snap-in connector on the back of the cluster. If there is power at the connector, then the issue is with the cluster/printed circuit. No power means there is a break in the wire between the headlight switch and the cluster.
The circuit is simple and wiring problems are rare; usually the connector is the problem. A redundant ground using a jump wire can be attached to the cluster to double check the ground circuit.
I would like to install a collapsible steering column in my 1965 Ford Mustang hardtop. I cannot understand why no one has come up with an aftermarket collapsible column for the '65-'66 cars. Or, if it's not effective to produce aftermarket, how about a conversion kit to put a collapsible '68 column into the early cars? It seems strange that with all the new safety updates for early cars, like 3-point shoulder belts, dual master cylinder, and front disc brake conversions, why wouldn't a collapsible column be available? Do you know of any manufacturers that are in the process of designing one?
Via the Internet
Flaming River (866/815-3677; www.flamingriver.com) offers a tilt/collapsible steering column complete with an installation kit. It is very high quality and allows use of the stock steering wheel if desired. Adding a collapsible column to an early Mustang will require a steering box modification. The shaft from the steering wheel down to the box is a single long piece, so it has to be cut so a separate column shaft can be used. The installation kit includes a coupler to join the old steering box shaft to the new column shaft.
My 1967 Ford Musang hardtop has a problem with the fuel gauge. When I turn on the ignition, the needle correctly indicates how much fuel is in the tank. But after half a minute, the needle moves past FULL to the stop, to the point where you cannot see it any longer. The temp gauge is working fine. Any ideas to fix this problem?
Michael D. Klör
Via the Internet
It appears that the circuit between the fuel gauge and the gas tank sending unit is shorted to ground. If the wire is grounded, the gauge will read overfull as you have indicated. Try disconnecting the yellow/white striped wire on the gas tank sender to see if the gauge no longer responds. If so, then the short is in the sending unit. If not, trace the yellow/white wire from the gas tank up into the trunk area and around the left rear wheelwell to look for a bare or damaged spot in the wire. It is common to find that the wire has rubbed through, as it is relatively unprotected by the thin trunk mat.
The wire continues up the driver side of the rocker panel and under the sill plate to connect to the underdash harness behind the kick panel. Any damage to the wire should be evident.
Let us hear from you. Send your '65-'73 Mustang questions to: Beyond Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to firstname.lastname@example.org.