I JUST FOUND a 1990 with 10k miles. The original owner said he had the battery replaced just before putting the car up for sale.

The "INFL REST" stays on all the time and the seat belt indicator is on all the time.
I have a service manual per the indications in Chapter 9 SIR SYSTEM DIAGNOSIS I should go to CHART A, I started the steps listed in CHART A but was unable to get pass Step 1. After shorting pins K and A on the ALDL CONNECTOR I have no indications on the panel.

Can anyone help in solving this problem?

Fuzzy

 

Make sure the plugs off of your seat belt holder are connected.

 

I have a 1990 that had dead battery replaced and have exact same problem-seat belt lite and infl rest. I'll look at belt conection too. Hope someone has answer.

 

I read somewhere that the solution to your problem is to find both airbag sensors and remove them. You will most likely find crosion on the back sides of them, clean them up as well as where they contact on the body and then apply a film of dielectric grease to the backside of the sensor and reinstall. Most likely will fix your problem. The newer C4's had the grease applied to them at the factory, that is why it is less problematic than the older C4's