1989 2.6 ram 50

[leojohn]

my truck runs great but red warning light on dash comes on and goes off seemingly with no ryme or reason . will 02 senser do that . .The head was changed from jet valve to non jet valve burt other wise stock and runs great hahah . what will cause check engine on these models . thanks

[lush90]

I would try to pull a code from the ecu and see what is triggering your check engine light. It can be done pretty easily with an analog voltmeter. There are plenty of online sites that will walk you through the procedure and give you the listing of the codes.

[dmr8x2]

the carb engines don't really have an ECU
it is more of an AND ,OR circuit
but th 02 censer will turn on the dash warning lite
the dealer might have a tester for the engine
but my guess is that they are long gone