99 GMC Suburban Door Locks w/not function

DOLFAN4EVERUS

MEMBER
1999 GMC SUBURBAN
165,000 MILES

I recently purchased our 99 GMC Suburban. It is equipped with keyless entry/security, however upon delivery of the vehicle I only received 1 key and no fob(s). Here is my problem: Since I have no key fob the only way to unlock/lock the doors is by the thumb/finger locks or key. None of the lock switches unlock/lock the doors and I get no distinct click from the relay. If replacing the relay does fix this problem, what should be my next action? Is there a way to check the continuity of the relay to ensure power is getting to the pins?

1 Reply

JDL

MECHANIC
16,098 POSTS

I'd check voltage and ground at the relay. Unplug the relay, use a testlite between orange wire terminal and black wire terminal. The test lite should come on, if not check voltage and ground at wiring harness/ where the relay plugs in. The terminals are lettered.

Blue and gray wires are lock. White and tan are unlock. Because the lock actuators are reversible, the wire colors should between between voltage and ground, depending on lock or unlock.

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