Volvo Troubleshooting Questions? Ask a Mechanic for Answers ASAP
Hello, sorry for the delay. There is two things I can think of that you have not checked that could be you issue. 1 the wiring harness installed may have the knock sensor and the engine temp sensor swapped. I have done thins and it will cause a no start. Also there are two relays on the passenger side strut that are black. These are a system relay and a cooling fan relay. You can swap the relay as they are the same and see if the vehicle starts. The connectors I am talking about for the temp sensor and the knock sensor are under the intake but you should be able to reach them. I am not sure on your vehicle if these connectors can be swapped though due to the age. Make sure all the wiring is connected properly if any of the connectors are the same especially if they can be swapped. Make sure that the wiring harness is correct for the year as there are Regina and non Regina vehicles that have different harnesses. If this corrects your issue please give me a positive review.
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