No start 1991 sonoma 4.3 2wd

Engine cranks, no start. All fuses good, but no power to fuel pump, running lights, headlamps, interior lights, heater a/c, or radio. Turn signal, brake lamps, and hazard flasher all functional. Issue began after install of aftermarket dash cig lighter and attempt to use. melted headlamp switch (has been replaced), killed power to radio (which was powered by voltage on courtesy light circuit- Orange wire, by previous owner) . In an attempt to restore radio to functioning state caused crank no start problem. Replaced fuel pressure relay, no change.

Possible replace module under dash passenger side floorboard?

Please advise options.

Engine cranks, no start. All fuses good, but no power to fuel pump, running lights, headlamps, interior lights, heater a/c, or radio. Turn signal, brake lamps, and hazard flasher all functional. Issue began after install of aftermarket dash cig lighter and attempt to use. melted headlamp switch (has been replaced), killed power to radio (which was powered by voltage on courtesy light circuit- Orange wire, by previous owner) . In an attempt to restore radio to functioning state caused crank no start problem. Replaced fuel pressure relay, no change.

Possible replace module under dash passenger side floorboard?

Please advise options.

I would check all fuses and fuse links and wiring first.
Does it have spark to spark plugs?
Does fuel pump relay have 12 volts power to it?

Yes, spark to plugs tested with inline spkplg light tester.

"Does fuel pump relay have 12 volts power to it? " 1 of 2 mounted to firewall driver side?

Thought I should fill in a little more background, might help...

Revised- Engine cranks, no start. All fuses good, but no power to fuel pump, running lights, headlamps, interior lights, heater a/c, or radio. Turn signal, brake lamps, and hazard flasher all functional.Testing found melted contacts inside headlamp switch (has been replaced).

Issue began after install of aftermarket dash cig lighter and attempt to use, noted power to radio failure. When driving home, wiggling head unit would cause intermittent power return to stereo.

Crank-No Start issue is direct result of my attempt to get my stereo to function again. My guess is tension to wiring caused failing connection to completely fail or other control circuitry fried. Or I activated anti theft.

Possible replace module under dash passenger side floorboard?

Please advise options.

Yes, spark to plugs tested with inline spkplg light tester.

"Does fuel pump relay have 12 volts power to it? " 1 of 2 mounted to firewall driver side?

Thought I should fill in a little more background, might help...

Revised- Engine cranks, no start. All fuses good, but no power to fuel pump, running lights, headlamps, interior lights, heater a/c, or radio. Turn signal, brake lamps, and hazard flasher all functional.Testing found melted contacts inside headlamp switch (has been replaced).

Issue began after install of aftermarket dash cig lighter and attempt to use, noted power to radio failure. When driving home, wiggling head unit would cause intermittent power return to stereo.

Crank-No Start issue is direct result of my attempt to get my stereo to function again. My guess is tension to wiring caused failing connection to completely fail or other control circuitry fried. Or I activated anti theft.

Possible replace module under dash passenger side floorboard?

Please advise options.

Find fuel pump relay and check orange wire to it for 12 volts power.
Fused by ECMB fuse

OK, no power to relay and to any of the fuses on far left row of fuse panel, which control all the systems currently failing.

The fuseable link you mentioned would that supply the power to that bank of fuses?

OK, no power to relay and to any of the fuses on far left row of fuse panel, which control all the systems currently failing.

The fuseable link you mentioned would that supply the power to that bank of fuses?

There is more than one fuse links.
Get a good wiring digram and check all power feeds.
Does ECMB fuse have power to it?
If not it is a fuse link or ign switch or a wiring problem.
Let us know what you find.
Good luck

I think I found the problem...

On the wiring loom behind the engine close to the dist, I found a connection that had melted. 2 wires clamped together.

ran a jumper to test and it fired right up.


THANKS for your wisdom

Now that its running again, lets consider the cause and see what you think.

I bought the vehicle from the local garage as is, for $1800 smogged. It had 2 owners and it was a commercial vehicle at some point and is working on 250K miles.

Heres a few things I noted.

When I got it, the cigarette lighter was missing from the dash socket, the entire ashtray assembly was missing, light hanging down.

The glove box light was missing, socket and all.

The cab light cover in the back was missing.

Some of the gauge lights were out, one turned on after tapping on the dash plastic cover a couple times.

I think the a/c would come on in the heater selection and the blower was intermitent.

The tilt steering is sloppy as hell and there was an aftermarket Loctronics antitheft device installed. (which I removed) Im not worried about it, thats what insurance is for.

The factory stereo was spliced, finger twisted together and taped back in and was powered by an orange wire that had a black ground wire with it (wire cut but not used) the 2 floor lights have the same orange and black pair wiring.

The orange wires insulation to the cig lighter was cut back and the wire exposed, but not cut.

When I found the link, on one side, the insulation on the wiring was hard and brittle and slightly darkened. At this link, 1 wire is linked to 2 smaller wires. There was a lot of oxidization(?) at the break.

Could this be symptoms of a failed stereo instalation with the first time almost burning the link complely? Possibly popping a fuse each time the cig lighter was used?

Thanks.

I think I found the problem...

On the wiring loom behind the engine close to the dist, I found a connection that had melted. 2 wires clamped together.

ran a jumper to test and it fired right up.


THANKS for your wisdom

You are welcome and thanks for posting back the fix.

Now that its running again, lets consider the cause and see what you think.

I bought the vehicle from the local garage as is, for $1800 smogged. It had 2 owners and it was a commercial vehicle at some point and is working on 250K miles.

Heres a few things I noted.

When I got it, the cigarette lighter was missing from the dash socket, the entire ashtray assembly was missing, light hanging down.

The glove box light was missing, socket and all.

The cab light cover in the back was missing.

Some of the gauge lights were out, one turned on after tapping on the dash plastic cover a couple times.

I think the a/c would come on in the heater selection and the blower was intermitent.

The tilt steering is sloppy as hell and there was an aftermarket Loctronics antitheft device installed. (which I removed) Im not worried about it, thats what insurance is for.

The factory stereo was spliced, finger twisted together and taped back in and was powered by an orange wire that had a black ground wire with it (wire cut but not used) the 2 floor lights have the same orange and black pair wiring.

The orange wires insulation to the cig lighter was cut back and the wire exposed, but not cut.

When I found the link, on one side, the insulation on the wiring was hard and brittle and slightly darkened. At this link, 1 wire is linked to 2 smaller wires. There was a lot of oxidization(?) at the break.

Could this be symptoms of a failed stereo instalation with the first time almost burning the link complely? Possibly popping a fuse each time the cig lighter was used?

Thanks.

Just give the wiring so tender loving care.:rofl: