My son has a 1989 GMC pickup that he just bought and we can't find the ignition timing bypass wire. I understand it should be a tan wire with a black stripe. I had the same on my 1987 GMC and it was located at the firewall between the distributor and the master brake cylinder.
I looked around in the 89 truck and can't seem to find the wire.
Anyone know where it could be located?
Thanks
Al I can suggest is that it is near the distributor, branching out of a main engine harness leg behind the engine. Perhaps it is taped up really close to the harness, or perhaps the ignition system has been modified or tampered with.
Toyota MDT in MO
Look under the black plastic cover on the passenger side of the engine compartment firewall. Just did a 1990 not 2 hours ago...
I might be imagining it, but I thought in my 89 S-10 it was on the inside of the truck down by the heater box/passenger foot area under the carpet.
That's not your imagination, but it is unrelated to the OP's full size truck EST bypass wire location.
Toyota MDT in MO
I did look by the distributor and couldn't find a tan/blk wire. Found the wires that go to the coil, pink and white and also found a single violet wire that had an inline connector.
I will try to check the black plastic cover.
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