Chrysler Repair: headlights problem 89 chrysler GTS

Question
Hello Roland,

my headlights on 89 lebaron GTS shut down during cruise after driving 2km or 2 minutes. They switch on back almost immediately, and then switch off again. Time between on and off is shorter and if I switch them off for 10 seconds, they will stay ON longer - maybe 1 minute. It started with shutting OFF brights when they were ON 1 minute or little more. Maybe there is serious problem with wires or grounds, because now electric mirrors doesn°t work, speedometer work, but odometer and RPM doesn°t too, and also rear wiper. I will appreciate any answer. Thanks.

Patrik

Answer
Hi Patrik,
The headlamp circuit would best be diagnosed with a voltmeter or neon 12V glow lamp, using that at the headlamp switch in the instrument panel. The voltage to that switch comes from the battery and passes first through a gray fusible link wire near the battery and from the 'wire-like' fuse it goes on a red wire to the ignition switch arriving on terminal B1. Inside the ignition switch there is a circuit breaker which should only open up when there is a short circuit in the headlamp wiring, but the breaker may be wearing out as an alternative explanation.  When you turn on the headlamps voltage appears on a light green wire at terminal H of the switch and then goes to the dimmer switch which chooses high or low beams. So you could verify whether when the light goes out you loose voltage at terminal B1 (in which case the fusible link/wire may be intermittent or you loose voltage at terminal H (in which case either the circuit breaker is failing or there is a short in the headlamp wiring that is causing the circuit breaker to open). To check out which you could measure the current being drawn on the light green wire to see whether it suddenly jumps up then the breaker opens or the circuit breaker just opens on its own accord. Try these tests while at rest, and see if what you observe when moving is identical or not in terms of the headlamp failure time/behavior.
The electric mirror is powered by fuse 6 under the dash, while the rear wiper is powered by fuse 7. So check those fuses to begin.
The odometer is gear driven and so you will need to get a replacement gear (try www.odometer gears.com) and then remove the cluster and replace the gear. I can send you instruction on how to do that. There are two gears and usually it is the 20-tooth gear that fails. The tachometer has a 'tachometer drive module' also on the circuit board. See if the same web site sells that or go to a dealer parts counter. If plugs in, I believe.
Let me know how it goes.
Please read the PS below and respond to it.
Thanks,
Roland

Roland