Rks1

Yeah, my batteries aren't charging. Is there a way to test the pcm without a scanner?
Also how much do used pcm's run?

patdaly

You have to fix your Tach problem before you go any further, without it reporting, the Alt. will not charge and the Trans. will not work properly.

I will almost bet you have a wiring issue, not a bad PCM, starting in 95 or so, they protected the power side of the PCM from shorts.

Did you ever get your FSM?

Rks1

Hopefully it will be here this week, that way I can at least have a idea where to start looking.

Fueling around

Go to the dash fuse block & check #12 which is a 15amp. That fuse (circuit) provides 12 volts to all the dash idiot lights & gauges for them to operate including the tach

Rks1

All the other guages and lights work except the tach. I'm not getting a check engine light in the dash and it doesnt light up when the ignition is turned on so I was wondering where it is located in the cluster?

patdaly

Rks, read this thread and it might help you out a bit.

https://www.dieseltruckresource.com/...t-t186943.html

Rks1

Thanks, I wanted to know is this the fuel shutdown relay? There was a wire inserted in the connector as a bridge. The truck will run even if the relay is removed. If the jumper is removed the truck will not start even with the relay in. Could this be the cause of the no charge no tach problem. I have read post about the no start problem but have never heard of anyone bridging this connector. Also what are the two red wires in the last pic for they were disconnected from the battery.

Rks1

Any help on identifying the relay my fsm is on back order and wont be here until the 5th.

patdaly

Wow, someone has hosed your wiring.

That is the fuel relay, probably why they jumped it is they were not getting the coil engage voltage. If I remember right, that is a part of the same circuit that provided power for the ESS.

Let me look around, I might have taht circuit saved on my puter.

The red wires are a mystery, can you track them back to see if they go into the factory wiring or are a remnant of a old installation.

patdaly

Here you go, not the best, but the best I have right now.

Rks1

Thanks for the help, when I called the auto parts store to price that relay I was told that that part number was for an airbag relay. There is also another relay on the left side of the one pictured that screws into the firewall. What are the wire colors of the fuel shutdown relay? Also does anyone have a part number for it. Also the trucks started direct wired to a starter button in the cab using speaker wire that goes directly to the starter. The button activates the starter whether the ignition is on or not. Is you try to start the truck by turning the ignition it will not work.

patdaly

LOL, Your Auto Parts store might know Toyotas.........

Thats the relay, they use the same relay in plenty of different places.

For your fuel relay, from the Battery to the 12V power to run the fuel solenoid will be Red/Black stripe the other side of the relay to the Solenoid ( power side ) will be Red/Violet stripe. The engage circuitry ( coil ) is from the starter to the relay will be Brown and from the relay to ground will be Black and Tan.

Power side wires are 10 Gauge, engage side are 12 Gauge in, 18 gauge to ground.

The relay right next to it is the fuel heater relay, but it has red/tan and red/black 14 Ga wiring, should be easy to make sure you have the right relay.

Rks1

Well from the paperwork I found in the truck it looks like it came from some type of equipment company. I think that when the truck started to have problems they bridged the fuel shut off relay and wired the starter to a push button so that the truck will start.

They never bothered to fix the trans harness plug and just sent it through the auction. That's where my cousin bought it and thought it was just a trans problem, so he took it to a shade tree mechanic that gave him a filter and fluid change for $1500. lol Then gave him back the truck in the same condition saying that it was an electrical issue.

From the diagrams I have been looking at the starter will not engage from the ignition without the fuel shutoff relay present and functioning properly?

Or is there yet another problem I need to chase down?

bud300ft

to see if trans is shifting ok go to under hood fuse box find trans relay take it out . then try manual shifting it. start in 1st go to 2nd then 3rd if it shifts ok then it is in your burnt wiring harness . when you try this shift pattern you must go to neutral then back to 1st to start over. if you dont you will be in 3rd gear. did they replace od solenoid gov sensor or gov pressure transducer

patdaly

I think it is the other way around, the fuel shutoff relay will not drag in unless the starter is properly feeding it. I do confess to not having to deal with this issue yet on the CTD, but I do know the fuel solenoid is split into 2 circuits, a Drag in and a Hold circuit. I will try and research it better this weekend.