Service engine soon

[Txsilverado87]

I have an 87 Chevy r10 tbi 350,I was trying to figure out why my ses light wasn't coming on.I pulled the gauges and found that the bulb and plug where missing.The bulb and plugs for all other three indicators where there for the brake,seatbelt and 4wd.My truck isn't 4wd,so I was kind of thinking maybe previous owner may have put service engine bulb in wrong slot but I've tried some different things to get this light to illuminate and nothing.Maybe try to trace the wire from the ecm to the light.Any input on this would be appreciated

[Captkaos]

Is there a bulb in the SES light section?  Is it a known good bulb?  Key on should illuminate the SES light.  If it isn't coming on you may need to trace the wire.  If it is getting power it may be a bad connection at the cluster printed circuit.

[Txsilverado87]

Key on is only illuminating brake light and bulb and socket missing in ses

[Captkaos]

So there is no bulb in the SES, just move one over to it...

[Irish_Alley]

just move one over to it...

you could just move the brake light bulb since you know its good. also on my 91 the contacts where dirty and had to be cleaned up a little.

but if the bulb still doesnt light. use a voltage meter and see if the copper contacts on the printed circuit are getting power (when you first turn the key on). if they are then your bulbs the problem, in not then trace the contacts (one will be ground) to the dash cluster pigtail and test there

[Txsilverado87]

I took the 4wd bulb and used it,i didn't know these where made this way and from wiring diagram in Haynes repair manual,well the diagram aint worth a nickel.I learned something new today and that's a good thing,thanks for all input on this topic.PROBLEM SOLVED

[Captkaos]

The wiring diagrams are in the tech section