[St Elmo]

a few problems.

1. When I turn on the high beams, the fog lights go out but high beams don't come on.

2. I just replaced the headlight bulbs with a set that are one step above basic part. The left bulb flickers and the right bulb works fine. I switched the bulbs from left to right and still the same problem.

This did not happen until I replaced the bulbs and I do not see any loose wiring that might be causing the problem.

All fuses I have checked so far seem good.

A while back I tried replacing the multi-purpose switch on the column and that did not help. Could the Central timing module be part of the problem?

I have eliminated the obvious causes that I could think of.

Feel free to answer here or by E-mail. Thanks

 

[oldmarine]

About a year ago I had an issue where all lights - headlamps, tail lamps, instrument lights, would flicker off for 1 or 2 seconds then back on. After troubleshooting everything else and confirming all wiring and connectors were good, I replaced the CTM. Haven't had any problems since.
I found one on eBay for $90 shipped. Make sure you get the correct part number - the CTM differs for base model and high line models.

 

[St Elmo]

The bugger of it is this. The problem started with the high beams not working. All other lights are working.

 

[oldmarine]

I'm attaching the wiring diagram for the headlights from the service manual. There are only three components involved for the headlights - the light switch, the multifunction switch, and the CTM. The CTM is the last component before the lights themselves. And even though in my case all lights were affected, it is possible that only the high beams could be affected in the CTM.
If you want to back probe the wires in the connectors, you could check and see if you are getting 12V at pins 2 (red/orange trace) and 3 (light green/brown trace) of connector C3 (12 pin connector) on the CTM.

 

[St Elmo]

Some folks say you don't need to get the CTM coded. But if it isn't what does that affect?

 

[oldmarine]

I have a base model Dakota/CTM. Mine required no coding. High line versions cover more systems, and I did find in the manual that the CTM must be programmed with a DRBIII scan tool (dealer?) to enable the vehicle theft security system (VTSS) if installed. The sentry key immobilizer module (SKIM) (chipped key) and PCM must be programmed with the DRBIII scan tool to accept new keys, but it didn't mention anything about the CTM for that.

 

[St Elmo]

Mechanic says I need a new central timing module.