2003 lincoln towncar no crank no start

is the starter circuit wiring diagram u sent for a 2003 lincoln towncar? the only reason i am asking is i don't see the pcm under the hood and i had seen where it was located in the kick plate on passenger side inside the car? can you verify the location? thanks Rich

I know this sounds basic but i am having trouble comprehending how the load side of the start relay works. if power is always at #30 does turning the key to start complete the circuit to #87 when the iginition switch is in run i have seen people jump across #30 and start the car on you tube could you explain it thanks im used to workin on 68 cougars and mustangs with no electronic shXt i have not done this work in along time (electrical)

Cournoyer wrote: is the starter circuit wiring diagram u sent for a 2003 lincoln towncar?

Yes.

can you verify the location?

Sorry, no I can't. The component locator says "Left (driver), rear side engine compartment. On firewall"
Occasionally, these are wrong.

if power is always at #30 does turning the key to start complete the circuit to #87

Indirectly, yes. The relay is, basically, a switch operated by an electro-magnet. In this application, the switch is normally open (voltage/current cannot pass through).

#30 and #87 are the load side. Power coming in on #30 (all the time) cannot pass through the relay to #87 until #86 & #85 get a power and ground. Turning the key to start sends power to #86. The computer, if theft/security checks out, sends a ground to #85. When #86 & #85 get a power and ground, it creates an electro-magnet. The magnet pulls the "gate" between #30 & #87 closed, allowing voltage to flow from #30 to #87.

If either #85 or #86 (control side of relay) lose the power or ground, the magnetic field will collapse and a the "gate" between #30 & #87 (Load Side) will open back up, stopping current flow through the load side.

Hi , this morning I just went down and pulled out relay and did a voltage test on the #30 pin in run position i have 10 volts in start position i have 12.1 volts that looks low in run position . I did not check at the fuse it started to rain i will go back out there and check the fuse voltage under load if it lets up . also i did pop the cover on the relay and put it in socket without cover and the 85-86 side looks like it is engaging in start position . and it clicks while it engages this is with the start post which i took off last night and left hanging so that side is open.

i went back out when rain stopped, i have 12.3 volts at fuse i have 10.3 volts on 30 pin when in run . i can take my jumper from the starter and crank engine on the fuse box post where short cable from battery runs . when I try to take my jumper and put key in run and touch the #30 post i get no crank , what i do get is the relay that runs the abs#209 clicking also over by the abs i hear electrical sound. mind you 'im not holding it down but for 1/2 second to see if i get a crank. I don't think the abs relay should be going off when i do that.

hi, Does the key itself (cylinder lock ) have anything electrical to do with the car starting?

Let 's back up, a bit. With the relay in place, Yellow/LT Blue wire disconnected at the starter solenoid, and key in the start position,....Do you read voltage on the disconnected starter solenoid wire? Does the starter relay click?

Cournoyer wrote: hi, Does the key itself (cylinder lock ) have anything electrical to do with the car starting?

Yes. Anti-theft. This would prevent the PCM from grounding #85...Pin #86 should still get power with the key in the start position, but without the ground on #85, no electromagnetic field. Relay #30 - #87 gate will not close. No power to the solenoid. But you should STILL get battery voltage on #30, all the time, and on #86 with the key in the start position.

HI i have 11.6 volts at the starter yellow n white solenoid wire with the key in start crawled under there and checked again late today with relay in . The other day after doing this test i hooked it up to the post and the voltage dropped down to .6v in start

there is no anti theft problem nothing on dash and when i turn the key to star the dash board (on top of center dash stays on 3 seconds then goes of like owners manual says it should . what about neutral saftey DTR switch will that cause the same effect as anti theft?

the relay closed on the control side when i opened it up and put it in and looked at it and the load side buzzed

the relay closed on the control side when i opened it up and put it in and looked at it and the load side buzzed

Have you tried a different relay? If turning the key to the start position activates the relay, the starter should crank.

With the relay removed, jumping #30 and #87 together should crank the starter. Does it?

tried different relay no it wont crank might be pcm or dtr